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Lucy in the sky with deadly radiations: An attempt to make a grand tour using kerbalism


king of nowhere

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10 hours ago, Spaceman.Spiff said:

Maybe someone else has suggested it, or you don't want to, but have you considered rotating crew?

Not sure how difficult it would be, but if you did a Kerbin assist then you could send up a fresh crew during the flyby, the capsule would just need a lot of DV to reach escape velocity, dock, and then return to orbit.

I did consider it. there are, however, multiple difficulties. if i send a new crew to the DREAM BIG, I would need to build and launch a new vessel and send it to jool to meet the rest of the crew. that's a 2 year trip, unless i make an oversized rocket with extra fuel to cut on travel time. And it will be subjected to radiation, the hardware at least. and, more important, after those two years the new crew would be just as stressed as the old one. after every breakdown they lose 50% stress. A new crew would have to be less stressed than that, and it seems stress management is bugged. and then i would send back the highly stressed crew with the same ship, and malfunctions could be a problem.

Or, the way you suggest with a kerbin assist, that would remove the problem with sending a new ship all the way to jool, but it would require to change all the flight schedule. Finding a Duna-Kerbin-Jool trajectory without stretching travel times is not easy. in stock game, or with unmanned probes, one can wait a couple of orbits to get a jool insertion five years later at a lower cost, but not in my case. and i need to be at jool at year 8 for the launch windows, and my fuel budget doesn't give me much leeway.

on the other hand, the DREAM BIG was designed specifically to tank a lot of malfunctions - i was expecting space weathering to be harsher, though i was also expecting less crew breakdowns, so the two compensates. there isn't a critical systems of which i don't have at least 5 copies, and i can lose 70% of my stockpile of practically anything and still go on.

so, ultimately, attempting to rotate the crew would generate many more problems than it can solve. especially considering the breakdown situation seems under control for the time being.

 

it would also be less elegant, though if i do nothing but transfer crew i could still call it a grand tour. that's a secondary consideration, but it's still there. I did mention in some of the updates i considered rotating crews, that was mostly when i didn't knew how to fight radiations. I would do it if i thought it was necessary, and actually a workable solution

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Part 8: We can't go there, mon. That's the forbidden radiation belt

Running a Jool 5 is made significantly more complex by deadly killer radiation belts encompassing all three inner moons. It was a race against time to avoid my kerbals getting fried, and then it was a race against orbital mechanics to avoid running out of fuel.

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The difficulties are overcome, and all the joolian moons are successfully visited. But new challenges loom

8.1) A quick update from Dolphin 2 and Digger 1

Spoiler

We left Dolphin 2 well set on its way to Kerbin. The only unknown was the impact of solar storms. Well, surprisingly, it turns out that it has enough shielding to pass them unschated.

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Habitat radiation being negligible during a solar storm

Which I'm having a really hard time coping with. The only things standing between the hitchhicker compartment and direct exposure to Kerbol are one clamp-o-tron (50 kg), one structural tube (100 kg), one 4k battery (200 kg) and one food container (80 kg empty, 860 kg full, currently close to empty). Barely half a ton! After all the trouble I went through, half a ton of material was enough to reduce habitat radiations to basically zero??? What the hell? Why did I make a 4000 ton ship if a tiny 15 ton pod was just as effective? I feel cheated :D(just joking, of course. And the obvious answer is that the 4000 ton ship is much more cool).

I also had some issues where it would alert me that I would run out of oxygen in less than one year, despite another menu telling me I'd last over two years. and despite having a chemical plant that should recycle oxygen. Well, I did notice some higher than expected oxygen consumption, but I still have more than enough.

So, no problems there.

As for the now-unmanned Digger 1, previously abandoned in Dres orbit, I sent it back to Duna, where it can eventually rejoin the DREAM BIG. Without a crew to worry about and with the ship in generally good repair, it doesn't require direct attention. If I'm really unlucky I will lose the antenna, then Digger 1 will miss the injection burn at Duna and keep hurling through space. Not particularly important anyway.

8.2) let's split up again

Spoiler

The last year of navigation for the DREAM BIG went smoothly. Few storms now that the sun is in a minimum, so I could time warp much better. It took about one afternoon to complete the trip.

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the DREAM BIG seen from a docked Digger

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First sighting of Jool without image magnification

I had time to refine the plans for Jool insertion. As it turns out, my original outline didn't properly account for how the radiation belt tails well past Tylo's orbit, so the previous trajectory for Pol was still too dangerous.

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A reminder of the size and position of the inner and outer death zones.

I set out to refine the transfer, making the first apoapsis burn longer, so that it would raise periapsis to 90M km. This would miss Pol on the next orbit, but a further manuever would still see a Pol injection two orbits later.

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Start on the dark yellow line coming in from the top of the image. Free gravity assist at Tylo, quick pass in the death zone on the green trajectory, apoapsis at 160k km, touching Pol's orbit. Here the first manuever, 380 m/s, is made (mostly prograde, some radial component to better match the elliptical orientation of Pol) kicking Home on the dotted yellow-ish trajectory. After one full orbit, at apoapsis again is the second manuever, 85 m/s prograde, raising Home to the violet dotted trajectory. Encounter with Pol two full orbits later; those manuevers were expensive, but now Home's orbit closely matches Pol, so it takes only 40 m/s for a mostly circular orbit.

Total cost is about 500 m/s, even cheaper than the previous one, and total time is 70 days after reaching Tylo, still within the limit of 200 days.

Meanwhile, I would detach Digger 2, coupled with the Can, and Digger 3, coupled with FU Eve.

The FU Eve is the only vehicle I have capable of landing on Laythe (or, more accurately, the only one capable of leaving it). I would slightly alter the Tylo flyby, so that it would end up on Laythe. Then it would quickly leave the death zone and reach Pol, where it would wait for Home.

Digger 2 will make a different correction manuever to have a low periapsis on Tylo, so that it can make a full capture burn. It will quickly explore Tylo, Vall and Bop, and then also rejoin Home at Pol. Besides being cheap, those trajectories are also convenient for minimizing exposure to the death zone.

I wonder if I ever run a mission according to the plan. I'm sure I did, and I forgot about it because it was boring. Now that I think of it, that's exactly why I stopped playing the career; everything was working, nothing ever required to kerbalize a mission. Since then I've been seeking greater and greater challenges trying to stay in that sweet spot where I have plenty of hardship and I have to keep improvising new solutions in front of unplanned problems, but I still succeed in the end. So far, this grand tour has been most enjoyable; every time I set into a comfortable rythm, soon I reach a new point where I have to improvise new solutions.

Anyway I split the crew with one scientist, pilot and engineer in every vehicle, according to radiation exposure. I kept Giostio, Ferdozza, Alrodo on Home, because they were the least contaminated; I am saving them for the Eeloo mission. On Digger 2 Giuritto, Pendatte and Iabretto, because they  were the intermediate level of contamination; they would have to spend several days in the death zone, better to take someone more healty. Digger 3 would take Bill, Sildona and Jeb. They were the most contaminated, so I set them on the mission that involved only a moderate stay inside the death zone.

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The three different trajectories around Tylo: green is Digger 2 going for a capture burn, blue is Digger 3 taking a steep turn for Laythe, and pink is Home taking a different turn to a high orbit.

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And the aftermath; Digger 3 trajectory stops at Laythe's SoI

Decoupling is just after entering Jool's SoI, some 50 days before reaching Tylo. The Diggers have food for about 160-180 days.

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Coupling Digger 2 with The Can and the Tylo descent stage

For convenience, I will now tell the story not in chronological order, but following each ship individually.

8.3) Traveling with Home

Spoiler

Soon after devising all those convoluted trajectories to save every possible drop of fuel, I was gradually having doubts about it all.

Do I really need to park the ship at Pol? Can't I just leave it where it is? Let's see

Pros Cons
I can get some small Oberth effect when I leave I would have to spend 200 m/s to get there, negating any tiny Oberth effect advantage
Easier to rendez-vous Harder to plan departures across multiple SoI
                                                                                                          Will get solar occultation, taxing my limited power supply                                                                
  Slow orbit, imposing time constraints on manuevers

Well, it's clear there's no real advantage to reaching Pol. So, at apoapsis I raise orbit just enough to clear the death zone

There you go, 300 m/s saved

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Home in its final orbit

Even the short (1 day) passage inside the death zone was enough to kick my crew from 10% to 40% radiation exposure. The editor granted  me I'd have 15 days. Great. I'll be lucky to survive 5.

8.4) Traveling with Digger 2

Spoiler

Digger 2 is the first to see action, landing on Tylo immediately. It's my 4th Tylo landing, but only the first where I don't crash on the surface a dozen times before succeeding. Though that may be only because I crashed on the surface a dozen times during testing. That's also my first lander that's neither scraped up together from limited money and part count (as the Tylo/Laythe lander of the Marco Polonium), nor optimized to do something else entirely and not really suited to Tylo (as the Dancing Porcupine rover).

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Not much to comment, just some scenery porn

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Detaching the last stage during ascent

Now the mission gets tricky, though. It takes a few days to reach Vall, and a few more to quit the death zone. I must be fast to keep the crew alive. At the same time, braking and circularizing around Tylo required some 1100 m/s. Extra fuel, because Digger 2 was also carrying the 70-ton Tylo descent stage. And now it will take 800 m/s just to leave Tylo, and after that the fuel budget is about 2000 m/s, and it must be stretched for all the other moons. I will never make it. Ok, Digger 3 still has lots of fuel (I almost sent it out half empty because its mission didn't include many long burns, but I realized I may need some change of program). I will send Digger 3 to Bop. And maybe Pol too.

Anyway, I spent one day around Tylo waiting for the Vall transfer. Luckily Tylo protects from some of the radiations, the death zone is less deadly here. But now I have a 4 day transfer. To speed it up, I had to burn more fuel. I mostly botched the manuever, ending up with an 800 m/s intercept on Vall. I carried through with the landing and all, then I realized my remaining fuel would only be enough to quit the death zone, then I'd have to send Digger 4 to recover the ship. Radiation level was 65% among the crew. I realized I could stretch my stay in the death zone one more day, so I reloaded and went for a 3 days transfer, costing only slightly more than the optimal 4 days trajectory. According to the tool there should be cheap Tylo-Vall trajectories lasting only 1 day, but I could not find them.

Anyway, I'm finally at Vall.

Here I have another problem. Remember my Moho landing and the lack of adequate thrust? Vall is almost as expensive to land. But now I have one more tool: I use EVA construction to strip down everything non-essential from the Can

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Away with the landing legs, they were only needed at Tylo. The solar panels can go, the battery will last long enough and they are basically useless anyway. The reaction wheel is removed, I don't need 3. All in all, I'm 300 kg lighter. On the down side, this time I am not able to spend the monopropellant, so that's 120 kg. I would remove also the redundant life supports (120 kg), one is more than enough for so short a time, but the editor won't let me touch those, probably because modded.

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one engine malfunctioned. I put 16 for a reason. No problem

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Here I still have solar panels because it's the first landing, the one I reloaded

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Vall landing, achieved. Jeb is pushing past 70% radiation, with the other crewmembers close behind. Which means it's time to RUN! GO GO GO GO! GET THE HELL AWAY FROM HERE!

Pity. The inner Joolian moons are beautiful places. I circumnavigated Laythe twice, and I did a half circumnavigation of both Vall and Tylo with the Flying Christmas Tree mission. Good times, especially Vall. This time I did not see the Vallhenge channel from my position. I miss crawling up the Shadar Logoth trail, climbing Kraken Maw peak, or running down Rover-Crasher peak, or traveling at twilight through Enchanted valley. But kerbalism turns those worlds into death traps, and no amount of repositioning the ship did any good in this case. I miss you, friendly Vall. But I must GTFO ASAP

I made it with 1600 m/s left, maybe I will manage to reach Pol. The alexmoon planner is telling me I need at least 1 km/s from Vall to Pol, and the window is many days away - of course I can't wait. But I discover a different trajectory that's as cheap as the cheapest regular transfers and starts now. Those manuevers are normally much more expensive than a regular transfer, I guess in this case it's not because Pol has too tiny Oberth effect to make much difference.

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A 500 m/s ejection from Vall to match apoapsis with Pol, then 177 m/s at apoapsis to syncronize with Pol on the next orbit. 276 m/s to enter Pol orbit. Total 950.

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This is just to show the ship status. Jeb is at 77% radiation, but still alive, and likely to stay such. There is still food for 116 days, with Pol encounter planned in 40 days.

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General recap; Digger 2, above Jool, is about to make the last manuever for Pol. Digger 3, in the lower left corner, is chasing Bop. Home is still in its parking orbit.

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Finally, Pol is reached

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Flawless landing! Ok, the gravity is low enough that the reaction wheels can pull it up

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From here, rejoining with Home is quite expensive, and I only have about 700 m/s left. But I have enough food, so I can afford to wait until Pol crosses the orbit of Home. Leaving Pol there will make for a much cheaper rendez-vous

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There you go, less than 350 m/s

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With 15 days left of food, a few hours of radiation tolerance, and 10 tons of fuel, Digger 2 successfully rejoins Home after a hard, but positive mission.

8.5) Traveling with Digger 3

Spoiler

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Digger 3 en route to Laythe

Even though Digger 3 was scheduled to only stay in the death zone for a couple of days (the Tylo-Laythe stretch is around 8 hours), it soon became clear that the radiations became gradually worse the closer to the center one got. Laythe is barely out of the greater death zone, but it's already much deadlier than Tylo or Vall. Even the atmosphere doesn't protect much.

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Laythe's atmosphere is unfriendly towards aerobraking, especially if you have heat-sensitive gigantor solar panels in exposed positions. In the stock game I would only burn the rockets enough for a capture, and circularize with slow, gradual aerobrakes. Of course, this time I'm quite in a hurry and that's not a feasible solution

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Hitting an island was achieved with the time-tested method of "saving and reloading with slightly different trajectories until you eventually get lucky"

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the FU EVE is still occasionally crippled by a kraken disaligning its pieces. This damage occasionally reverts upon reloading.

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The FU Eve last stage was specifically designed as a Laythe lander for the Marco Polonium mission, and it performed admirably. It has a base wide enough to land in the rough mountains of LaytheCRAP!

Yeah, it can take some slopes, but there are limits. Reload again.

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See? It can stay upright there, which is already more than most landers can manage

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And rejoining Digger 3 (reminder: it has the small clamp-o-tron on one of the lateral cylinders)

At this point Digger 3 has been in the death zone for less than 2 days, but the crew is already pushing close to 50% radiation damage. Time to move on, really fast. I start with a large prograde burn, not because I have a specific target in mind, but because it's the fastest way to escape the death zone. It took an extra day to cross the boundary, and by then the crew had accumulated 65% radiation damage. Damn, that was hardcore. Without the best (and heaviest) radiation shielding, I'd have died without even seeing Laythe.

After this manuever I went to take care of Digger 2 and its Vall stretch of the mission. During this time I realized I wouldn't be able to send it to all the moons (a pity, Digger 1 and 2 had the best science instruments, which is why I prioritized them for missions to moons I wouldn't visit otherwise), so I started planning to turn Digger 3 to Bop. It's somewhat uncomfortable to reach it from this unplanned orbit, but then, Bop is hard to reach from anywhere, this isn't really any worse.

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I start by creating a point of contact between the orbits. I do not try to equalize the orbital planes, that would be too expensive.

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This orbit has a period of 20 days, while Bop has a period of 25 days, so I will eventually overtake it. It will take a while because it is in the opposite side of the orbit, but a quick look at the food storage shows I can do it.

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Finally, a small nudge will syncronize passage on the orbital node for an intercept in 80 days

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Bop was the last moon I explored. For some reason, the food on Digger 3 lasted longer.

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Keeping constant check on FU Eve's engine and fuel cells

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And for the first time, I manage to land on Bop in decent sunlight! Also, nice sky view

Rejoining Home was also a tad expensive, what with orbital inclination and all that. But a Digger is intended chiefly as fuel tanker, it can manage. This time I didn't think to take pictures

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The DREAM BIG is reconstructed. I docked Digger 2 on a side to drain the kraken-riddled fuel tank in preparation for the Eeloo mission

8.6) Outlook for the rest of the mission, AKA I'm out of fuel

Spoiler

Digger 2 is set to go for Eeloo, paired with a Dolphin. I already tested the pairing going to Dres, and it performs excellently. Those ships have been very successful, and radiations haven't been a problem. It has food for 4 years and I already identified an Eeloo transfer for 2 and a half years, leaving one year to get back to Kerbin in safety. That transfer is more expensive, though, so perhaps Digger 2 won't have enough fuel to be brought back. It's ok, I actually expected to lose some much earlier. This part of the mission looks promising.

Less promising is the outlook for the DREAM BIG. It needs no less than 1900 m/s to return to Duna, including aerobraking as much as possible. Well, now that I finally have all the moving pieces out, I could make accurate calculations.

I have 1700 m/s left.

I kept saying that Home's fuel tanks are so big, even a Digger won't make much of a dent in them. Well, a Digger holds 200 tons. And I first sent Digger 1 to Dres. Goodbye to the first 200 tons. Then Digger 2 and 3 went out at Jool. They took 470 tons of fuel, including the Tylo descent stage, and they only returned 40. And now Digger 2 is leaving again, carrying 200 more tons. There's also the FU Eve, for 10 more tons. We're looking at 850 tons of fuel. Even Home's deep tanks aren't that deep.

I have several options now. At least, thanks to the Dolphins, the mission is not in danger. I am confident in the Eeloo landing. I can send a Dolphin coupled with the Can to finish landing on Mun and Minmus. I am now struggling for outstanding success.

I decided if I recover all the ships (excepting, at most, Digger 2 left at Eeloo) I can claim outstanding success. After such a trip, recovering everything in good conditions except a single shuttle would be great. If I lose more ships, it's only complete success.

Right now, I could ditch Digger 3 and 4. This decreased weight would increase the DREAM BIG deltaV to 1900 m/s. And then I could still refuel with Digger 1, back from Dres. But then, it would be no better than just taking the Dolphins and leave.

I could look for gravity assists. I am currently doing it. But it's not easy. Dres is useless, Tylo is too awkwardly placed, Duna is too small and I will pass it too fast to get a good kick, and Kerbin is too expensive to reach. I spent hours studying trajectories. Still, I may find something good there. Or I may just be forced to abandon the DREAM BIG. Time will tell.

Edited by king of nowhere
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Just a reminder, the rules for grand tour specify a  Kerbal needs to land on every planet or moon, so you will get a honorably mention even if you successfully landed on every object and returned safely, though your mission is still very impressive nevertheless, I enjoy it very much!

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On 2/5/2021 at 7:50 AM, Space Nerd said:

Just a reminder, the rules for grand tour specify a  Kerbal needs to land on every planet or moon, so you will get a honorably mention even if you successfully landed on every object and returned safely, though your mission is still very impressive nevertheless, I enjoy it very much!

You mean one specific kerbal, always the same?

Huh. That's a bother.

Well, I'm already planning a new one, with an improved ship, using the full isru rules of kerbalism, i.e. you need 7 million electricity to make a single unit of fuel. I planned a ship with 150 solar panels that should be able to make 1 ton of fuel per day at ike. It would spend many years refueling.

And then I'm planning another mission, much less inspired, that would use a small ship packed with food and drop tanks, and no attempt at isru whatsoever. I've been quite disappointed to discover that all the shiny new toys kerbalism give you are ultimately trap options. Not only a greenhouse weights 3 tons and would take 3000 years to produce its own weight in food+ oxygen, but for every kg of food it makes, it also makes 200 grams of oxygen, but it consumes 4 kg of water that are not recycled. If one is looking for efficiency, making no attempts at recycling anything is actually the most efficient route. Even all the luxuries I brought to keep my kerbonauts appeased are backfiring; for some reason probably related to glitch, the crew of my comfortable ship is actually getting more stressed than the crew of the smaller shuttles. And bringing 12 kerbals at once does for a neat mission, but ultimately it just increases four-fold the amount of breakdown losses I suffer. With that it should be relatively easy to make a grand tour by the rules. It would also be kinda depressing. Isn't the whole point of the last 50 years of space exploration to learn to live in space with less resources, recycling stuff and using local resources? They wouldn't do it if it ended up being less convenient than just making a new apollo mission, except bigger.

But, rants aside, I am fairly confident I can eventually make a grand tour according to the rules. Though this mission will still probably be much more fun (except for all the lag. and for the time i had to run 30 refueling missions from Duna with included docking with lag and couldn't even time warp too hard. And the days spent doing nothing but time warping, stopping for a storm, turning the ship around, waiting for the storm to pass, turn the ship around again, time warping until the next storm, rinse and repeat.... ok, it's a fun mission but it's full of terrible moments)

Edited by king of nowhere
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10 hours ago, Space Nerd said:

Just a reminder, the rules for grand tour specify a  Kerbal needs to land on every planet or moon, so you will get a honorably mention even if you successfully landed on every object and returned safely, though your mission is still very impressive nevertheless, I enjoy it very much!

3 hours ago, king of nowhere said:

you mean one specific kerbal, always the same?

huh. that's a bother.

As a further reminder, the challenge rules are flexible. In this case, I'm willing to waive the "one Kerbal lands everywhere" requirement, since it's near-impossible to fulfill when using Kerbalism.

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Part 9: Journey before destination

DREAM BIG has to find some gravity assists to reach Duna with its limited fuel. Digger 2 has to find a trajectory to reach Eeloo in less than 3 years, while saving enough fuel to land and possibly to return. Digger 1 has to make a Duna landing without control. Dolphin 2 chances a high speed atmospheric reentry. All objectives accomplished

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the second part of the DREAM BIG trajectory

9.1) Digger 2 pushes on to Eeloo

Spoiler

So, Digger 2 has just reunited with Home, that it must leave again. This time it will carry Giostlo, Ferdozza and Alrodo all the way to Eeloo. Dolphin 3 will accompany it, providing a safe means of return and precious food stores. Food is the limit here; there is enough for 4 years. Which is about the time it takes to get to Eeloo in the optimized trajectory. My kerbonauts would have just the time to plant a flag there before starving. I could send a second Dolphin, but I prefer not to if I can avoid it. And since Diggers have plenty of fuel, I decide to spend some of it to go faster.

On the other hand, I would also like, if possible, to recover Digger 2. No particular need, just because I hate to abandon a reusable vehicle that I like. And Diggers have performed really well. However, I lack a lander... wait, what am I saying? I want to save the Can for Mun and Minmus, but I still have the FU Eve. Let's send it, it's only 10 extra tons of fuel. It's like 30 m/s for Home, I doubt they will make a difference on reaching Duna.

Now another dilemma: I can send Digger 3 or 4, which has the docking port for the FU Eve, and hope to recover the ship. Or I can send Digger 2, which has a lot of science instruments I would like to use at Eeloo, but it has no small docking port, so I'd have to abandon it there... Or I could use EVA construction mode to take a spare docking port (Home still has a dozen small ones, from when I was considering including a dozen Wings) and attach it to Digger 2. It's almost too easy.

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Ok, perhaps I should have docked FU Eve first, and Dolphin 3 last. This was painfully hard, FU Eve kept hitting on stuff

Now the trajectory. I have food for 4 years. I know a Dolphin can make it back from Eeloo in one year. I want to reach Eeloo in two and a half years, so I can save 6 months of supplies for emergency. Good thing I thought to give Dolphins 3 times as much food capacity as needed. My concept of "emergency supplies" and "safety margins" has grown dangerously thin as this mission progresses.

I would also like to spend no more than 2500 m/s to reach Eeloo. This way I'd have 2000 m/s left, which are barely enough to get back to Duna. Alexmoon tool isn't helping; it can't even calculate Jool-Eeloo trajectories starting at year 8 and lasting less than 4 years

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The purple spot is where my travel solution should be

But I learned a lot since my first Jool-Eeloo transfer, back when I was taking my first baby steps in interplanetary transfers. That time it took me half an hour just to find a route for Eeloo. This time, I could immediately find intercepts, and in half an hour I found the one I wanted.

No, I did not get better at knowing interplanetary flight. Well, ok, I did a bit. But the greatest improvement has been figuring out how the game calculates "close approach". The main problem had always been that it suddenly deletes the good approach to find another 200 years in the future. After I figured out how to avoid that, it becomes much easier.

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480 is the bare minimum to leave Jool SoI. The direction doesn't really matter. This is one of the cases where you have to just point away from any regular orbit and make one of those scrambles transfers that include a large radial component and whose only logic is intercepting the target at the right time. I used similar trajectories to get to Gilly. Those trajectories are normally inefficient, but they work when you have low orbital speed and have to reach targets in orbits very different from yours. This is one such case ("low" orbital speed is relative to the sun, so still pretty high). One such manuever brings me to Eeloo with 840 m/s in slightly more than one and a half years, and from there it's another 840 m/s of intercept.

Not much else to report here. Both manuevers successful. Ship is holding up well, no problems with maintenance. Some occasional problem with kerbals having breakdowns and breaking stuff, but none of the critical components has been touched. Now there's only to wait

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One such breakdown resulted in a broken parachute. I am using EVA construction to get rid of it. Goodbye dry mass!

9.2) DREAM BIG finds a course for Duna

Spoiler

The DREAM BIG has to find a way back to Duna to refuel, with only 1700 m/s. Direct transfer from its current orbit would require 1900 m/s, even including some generous aerobraking. Gravity assists are needed. On the plus side, I have supplies for well over a decade, flight time is not a big problem.

It should be easy to find assists around Jool. I can go straight to Duna, or I can get a slingshot from Tylo, or I can even go to Kerbin... that's part of the problem. Too many possibilities. And none of them looks right.

Tylo, if we discount the radiation problem, never seem to be aligned right. If I had to go to Dres it would be easy, but I keep finding trajectories to lower solar periapsis down to 30M km. And from there it's rocket burn. And this removes all the advantages. I once found a direct route to Duna's orbit, but while Duna itself was on the wrong side of it. So much for the transfer window. I even found a direct intercept Tylo-Duna, but it reached Duna with an awkward angle, so that afterwards it was like 1300 m/s for capture.

Getting to Duna and getting a gravity assist from it to lower periapsis would be nice, if Duna gave a decent kick. Spoiler alert: it doesn't. I'd be going too fast to gain much speed from the planet. Maybe in 3-4 orbits it would be possible, but those would be too slow. I can also rocket brake at Duna; I can't get captured by the planet, but if I slow down enough, maybe I can get a more efficient gravity assist to get captured at the next passage... worth considering.

Kerbin is bigger and gives much better gravity assists. But it is also expensive to reach: 1400 m/s for a direct course, leaving me with only 300 m/s for further manuevers. I found a Jool-Kerbin-Kerbin double flyby that would send me to Duna in 6 years. But it's impossible to calculate further than that, trajectories start flickering - try planning too many manuever nodes too far in the future to see what I'm talking about - and I can only estimate I'd have still 600 m/s to lose to get captured. Maybe I could then get a gravity assist from Duna and have a more gentle capture and the next orbit, but it's a big risk without knowing in advance.

I even considered using a Jool assist, leaving Jool only to return to it one orbit later. Being so big, Jool must give a real gravity kick... except, it doesn't seem to. Perhaps because my orbit would be matching its own too closely.

All this was resulting in hours spent looking for trajectories, and it was giving me a headache. I made a breakthrough realizing I had to split the problem in two: leaving Jool first, and getting captured later.

And to leave Jool, I made some simulations, it's really better to use Tylo. Which does not want to cooperate.  So, step 1 is getting captured by Tylo.

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First manuever, top right of the picture, lowers apoapsis to Tylo's level. Follows purple manuever, it's a plane change to get perfectly equatorial, because this is already messy enough without having to also worry about inclinations. Green and red are just manuever nodes I made to force a simulation in time. I know if I keep up that orbit I will cross Tylo at some point, I just have to click "next orbit" until the game sees it too. Finally, in 66 days I reach Tylo. It's important that there is a low capture speed, and that the periapsis is placed right

But wait, Tylo was offlimits because radiations... oh, right.

Of course I wouldn't start planning for Tylo without a plan for radiations. The plan is very simple. Put all the crew in a Dolphin. Leave them parked in the current orbit. We're looking at 100-150 days; it's gonna be cramped, but it's manageable. When the DREAM BIG leaves, find a way to rendez-vous with it. With 15 km/s it won't be a problem.

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Dolphin 1 detaches from the DREAM BIG, carrying 6 kerbonauts away from the death zone

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A Dolphin isn't made for 6, but it's only for a limited time. The alternative, sending 2 Dolphins, was just too much hassle.

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The unmanned DREAM BIG now begins its new journey. Being lazy, I found more convenient to just use the Digger 4 engines instead of moving it

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For once, a correction manuever saved fuel instead of losing it. I don't know how, but I found myself with an even smaller Tylo intercept.

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Orbiting Tylo. 543 tons of fuel left, for 1430 m/s. Make it 1400 because I will rejoin with Dolphin 1, adding 15 tons.

For a long, long time, I would have considered a 500 ton rocket utter foolishness. I wonder how the myself of the past would have reacted to this mission

Now DREAM BIG is orbiting Tylo in an ellipse that stretches to the limits of its SoI. A small push will send it flying, and it will have 800 m/s of burn at Tylo periapsis already included. The only limitation is that I can't change the orientation of my orbit; I must make a prograde burn at Tylo periapsis to take advantage of it. This orbit points 45 degrees away behind the sun, the right inclination to exit behind Jool. I spent 300 m/s getting there, but now 200 m/s will see me to a Duna intercept; 300 m/s will reach Kerbin. What I gained in deltaV, I lost in flexibility, as I no longer can leave orbit whenever I want.

I must wait 50 more days for Tylo's orbit to be aligned correctly just when the ship is reaching periapsis. I would have been hesitant to leave the DREAM BIG so long exposed to radiations; except that traveling one year without shield at solar maximum taught me that radiations aren't that bad on hardware. Speaking of solar activity, it's now solar minimum; I've seen no more than two or three storms in the whole last year. When every storm forces me to slow down and turn ships around, it's a real time saver.

I spent several hours simulating manuevers. Eventually I settled for a Kerbin assist, with a future to be determined.

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With 300 m/s I can reach Kerbin's orbit, without intersecting Kerbin. For that I need a radial component to push up my solar apoapsis and slow down my trajectory a bit. Later I managed to reduce the cost of that manueverfrom 540 to 360 m/s. A second manuever fixes orbital plane, again I didn't want to be bothered by it. But I still have time to look for better trajectories.

This first manuever sends me on a Kerbin intercept 3 and a half years later. Here I can use Kerbin for apoapsis lowering. From there the game becomes inaccurate, but I know I will have options. I can lower apoapsis as much as I can in the first pass, and then a small manuever will see me to Duna on the second orbit (as shown in the image). I will still have around 800 m/s, should be enough for capture. If not, I can change my flyby to aim for a second Kerbin assist, and that could lower solar apoapsis all the way to 20M Km, and I am sure I can intercept Duna then.

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The Tylo ejection manuever seen from Tylo and from Jool. I was able to skip with the radial component by making the manuever a bit before periapsis.

Luckily, the ship was in contact during the manuever. There was the risk of having to do the burn when shadowed by Tylo. In which case I could have changed a bit Dolphin's orbit to be able to provide a radio bridge at the right time. Or I could have sent Dolphin to rejoin in Tylo's orbit; I already determined it's not as bad as the rest of the death zone, my kerbonauts could survive a few more days in it. In fact, I considered making that manuever anyway to save some fuel. I didn't because I didn't want to risk disturbing the planned manuevers, after all the effort I put into them.

Hey, maybe I did actually get better at interplanetary flight after all.

This manuever will happen in a fast part of the orbit, I need decent thrust. I decide to use the full engine pack, which requires removing Digger 4

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I put it to a specific docking port because, if you remember, I have some bugged fuel tanks that won't communicate with the rest of the ship. Some of my engines are attached to them, and won't work otherwise. So I transfer some fuel.

Then the proper procedure would be to move both Diggers at the front and sides, to keep the DREAM BIG symmetrical. I'd need to move both Diggers, and the Can too, since it blocks one of the needed docking ports. Too much of a hassle. I will move the fuel inside the tanks instead to try and compensate for the unbalance caused by a digger attached laterally, shifting all the available fuel on the opposite side of the ship.

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And hey, it worked! Despite 80 tons of Digger docked awkwardly to the side, the DREAM BIG is flying at full thrust perfectly straigth! Gotta love that engine pack. And with most shuttles removed and most tanks empty, they are pushing the huge mothership at almost 0.7 g! Home is surprisingly manueverable for its size, when it doesn't lag too much.

Ok, now that the DREAM BIG has left Tylo, it's time for the crew to return. I made a lot of rendez-vous in difficult conditions, this one can't be too hard, right?

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 :0.0: right? :0.0:

Ok, new strategy: the game won't give me an easy intercept, so I'll aim for the only one I can clearly see: the "escape from Jool" marker. I can aim my manuever to reach as close to it, at the same time. From there I will be close enough to finish rendez-vous just by aiming the target in the navball.

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It's gonna be expensive, but nothing is impossible with enough deltaV

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Dolphin 1 manuevers. It can actually reach 8% thrust with 4 ion engines, at Jool it's remarkable. But even more remarkable is that the persistent thrust mod started working! What could have been a sequence of multiple 6 hours manuevers was accomplished in minutes! Thanks to @JupiterJaeden for suggesting it.

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As Dolphin 1 gets closer, I can refine the trajectory better

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Outside of Jool's SoI, I finally see an intercept! Looking at the orbits is pretty useless by now

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Better to start braking in advance, wouldn't want too fast an intercept with ion engines

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getting closer...

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There! Year 8, day 262, the DREAM BIG has a crew again! The kerbonauts gleefully run around the mothership after being cooped up for almost 200 days

3 more years before reaching Kerbin. I hope I can reach 40M km before the new solar maximum, being able to use the radiation shield makes traveling much smoother.

9.3) Dolphin 2 returns to Kerbin

Spoiler

We left Dolphin 2 and its crew coming back to Kerbin after visiting Dres. Now their voyage is finally at an end.

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Approaching Kerbin at 10 km/s, it will only take 2 hours from the margin of SoI to crashing on the planet

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Slowing down a bit for a safe reentry

Now that I think of it, I had enough fuel to get into orbit. I could have tried to recover the whole ship. I was too worked up with testing the Dolphin at extreme speeds, though.

First I tried not braking at all. I hit atmosphere at 10.5 km/s and I disintegrated. Thermal shield overheated and exploded. The rest of the ship didn't have time to explode for heat, because excessive g forces killed it first. Wonderful!

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Jettisoning the habitation and service module

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Hitting atmosphere at over 8400 m/s!

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At 35 km deceleration is enough to knock out those kerbals. Good thing they are made of iron, humans would be unlikely to survive

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Now the capsule is decelerating real fast

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And at 20 km altitude, it's reached a sane speed

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It reached 37.7 Gs of acceleration during atmospheric reentry. So, I can probably push it up to 9 km/s if needed. 25 km/s are also an impressive speed. Probably reached in solar orbit

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Year 8, day 148: Bob, Val, Elionito are safe on Kerbin, after exactly 7 years in space

9.4) Digger 1 lands on Duna

Spoiler

The other leftover from Dres landing, Digger 1 was abandoned on Dres, but not forgotten. It was coming back to Duna in its own time, to wait for the DREAM BIG there. If refueled, it could also provide some extra fuel at a critical time.

Well, now it reached Duna, and it has enough fuel to enter orbit.

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One solar panel broke in the long years without maintenance

There is a problem, though: during descent, aerodinamic forces will be strong enough to destroy the antenna. No antenna, goodbye ship. I can close the antenna, but then I lose control. And without control I can't reopen the antenna again, because I set that in the difficulty options. I look at the kerbalism automation features. There are so many options: exposed to radiation, hard disk full of science data, entering atmosphere, exiting atmosphere, landing... but there is nothing whatsoever that would help me survive the landing. Without activating the rockets, I will crash on the surface at 30 m/s, turning an excellent space vehicle into an expensive modern art exhibit.

Wings 2 is still active in orbit around Duna, but its relay antenna is too weak. If I remake this mission, I need to either power up those little probes, or ditch them entirely.

I could just leave Digger 1 in orbit, but I'd like to land. That fuel could be useful, and the ship would be better protected against aging. It will be many more years before it can be serviced again. I'd just need to be able to turn on the antenna after turning it off.

Good thing, someone else somewhere had my same problem, and had the skill to develop a mod. Thanks to @Snark for his antenna snooze button!

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I can retract the antenna for atmospheric passage, and it will reopen afterwards

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This manuever was a bit harsh, but I want to make sure to land while in full communication with Kerbin

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Landed! There's no engineer on board to speed up ISRU, but then, DREAM BIG won't be coming for another 5-6 years.

Edited by king of nowhere
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  • 2 weeks later...

Part 10: A day in the limelight for Dolphin 3

The Digger 2-Dolphin 3 couple reaches Eeloo and lands the FU Eve. Digger 2 then takes a slow route to Duna, while Dolphin 3 makes full use of its xenon fuel to take a hyperbolic trajectory at breakneck speed to reach Kerbin well before the end of food supplies. In fact, it manages to reach Kerbin just as the DREAM BIG was passing there, succeeding in a rendez-vous with the mothership. there it swaps crew and picks up the Can, bringing it to land on Minmus and Mun before landing on Kerbin with most of its bits still attached. 

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10.1) Meanwhile, the DREAM BIG...

Spoiler

I still had to define an exact trajectory for the DREAM BIG. I had a plane change that would set it on the Kerbin flyby, and from there there were still many possibilities. Well, for start, the plane change was 190 m/s, but I suspected some savings would be possible. Indeed, they are. I got the same effect for 70

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Making a normal/antinormal burn away from the nodes got me with a high angle of intercept on kerbin, but orienting correctly the gravity assist fixed that too

After that, I experimented a bit with future trajectories. A direct duna intercept will never work. As you can also see from the image above, I cross Duna's orbit at a wrong angle, my intercept speed is too high. And I can't lower apoapsis more than that without crashing into the atmosphere. So I set off for the double assist, taking a smaller gravity assist to get in line for meeting Kerbin again in 2 years. Good thing I brought plenty of supplies and the ship is sturdy. I went back and reread some entries; just one real life month ago I was all "must burn extra fuel to minimize time". Was that really me? I can't believe I was so naive regarding deltaV and time requirements of this mission.

But then, I also went and read about my old jool 5 science mission. It was 2 months ago. It felt like an eternity. Feels like i've been running this mission for years.

Crew stress has been strangely quiet. No more breakdowns in a long while. Perhaps it was too many crew members. Now that I have 6, it seems stress levels are ok. One less thing to worry about.

The first couple of years of traveling, Kerbol was in its quiet phase. I got two or three storms in the whole year. Wonderful! I can use max time warp. But now solar activity is increasing again, to a storm every 3 to 10 days. And at every storm, I have to turn the whole ship around to point the engines at the sun, then turn it around again to point the solar panels. But I carry on with the sure hope that this ordeal is about to end, because at 39M km I will be able to use the active shield again, and no more need to turn the ship around.

However, it turned out that was unnecessary, for at 43M km I got another boon: my ship could stay powered while pointing the engines at the sun.

Well, turns out, with the greenhouses shut down (i have food for years, but i am short in carbon dioxide) the ship requires very little electricity, and the 10% exposure I get is enough. So, no more need to turn the ship around. And no need to turn on and off the fuel cells and the electrolysis all the time. I can wait until I can sustain the shield on solar power alone. which happens... NOW! year 11 day 124, active shield online!

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You should see the little lights transitioning from red to blue, but the image is kinda small

with the shield up, I can time warp at will even during storms. I almost forgot how convenient it was to simply ignore them. And now, aside for occasional manuevers and hardware maintenance, I can also ignore the whole DREAM BIG while I fly Dolphin 3. No more lag.

During all this time, I did suffer a single critical malfunction, to a small and completely irrelevant reaction wheel. I have around 900 m/s left.

10.2) Eeloo, I love you

Spoiler

After 1000 days of traveling in the cold darkness of deep space, without all the comforts of the DREAM BIG, finally Digger 2 reaches Eeloo.

Not much to be said about this part. Eeloo is hard to reach, but once there, it's a cakewalk.

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This last manuever was meant to park in an elliptic orbit pointing the right way to make the return trip cheaper. But I got the angle off, so it didn't help much.

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only one day from the rendez-vous, I have first visual contact with Eeloo. Of course i couldn't spot it sooner, I am approaching from the dark side

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Last round of maintenance before Digger 2 is left on its own for several years

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Detaching FU Eve. The honor of landing goes to the engineer Ferdozza, because the engine will need lots of servicing

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I like Eeloo but I never get to spend time on it. So here I take a suborbital jetpack flight to reach another biome

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And I even go out searching for rocks.

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Rejoining FU Eve with Digger 2. The space is narrow, but this time the manuever goes smoothly at the first try

10.3) Eeloo-Kerbin in 375 days

Spoiler

Landing rituals completed, the crew transfers to Dolphin 2 to return to Kerbin. Fast.

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Undocking Dolphin 3

There is food for 600 days (also, water for 700 days, oxygen for 6 years, and nitrogen for 10), but in the name of safety (yes, I can remember the meaning of that word sometimes) I want to reach the target in one year. There's been all kinds of glitches, who can say when some resource will start running out faster than it should. Even too many breakdowns venting food in space would do the trick.

Now, I felt confident on finding a fast return trajectory because i tested the dolphins before. And by "tested" I really mean "I used the debug console to send a dolphin around Jool - which is more or less the same distance than Eeloo - exactly once". So, I wasn't really completely sure that the same principle could be applied to any situation. But it was. There's very few problem in orbital mechanics that cannot be overcome with more deltaV

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Don't try me! I have 15 km/s worth of xenon and I'm not afraid to use them!

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The return trip begins. Goodbye, little dwarf planet. One day, I'd like to spend a whole year on your surface

Don't cry Digger 2, I'm not abandoning you! I will recover you at Duna with your brother Digger 1.

Of course, that requires finding a trajectory. Diggers can aerobrake somewhat better than the DREAM BIG, but this one is still a far cry from being able to reach Duna.

Well, I learned a lot on gravity assists when searching one for the DREAM BIG. And one thing I learned is, you can always count on a Kerbin assist. Even if you can't see the future trajectory after that, you are pretty much guaranteed that there will be one. So I sent Digger 2 to Kerbin, starting right now.

The optimal launch window would have saved 100 m/s, but it won't be for another 4 years. And an antenna malfunction would lose the Digger. Too risky. I'm left with 350 m/s. If the double Kerbin assist works just like it does for the DREAM BIG, that should be enough. 200 m/s to brake to 400 m/s intercept speed, which should be still a manageable aerobrake for a Digger. 50 m/s to land. 100 m/s left for correction manuevers. If the DREAM BIG is already there, I can also send another Digger to intercept

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yes, the parking orbit wasn't quite right to save fuel.

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The Kerbin trajectory. Of course, I will refine the flyby once closer

Now Dolphin 3 has a 7000 m/s burn to make. While limited to maybe 8% thrust from the little solar power. Good thing I have a mod to time warp during that, as this would have literally required days!

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Since I must point towards the sun, I did a quick reconstruction and shifted the solar panels to optimize energy in this situation

I could also see for the first time the fascinating behavior in passing from a solar orbit to a hyperbolic trajectory.

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veeery long, but still a regular orbit

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here the circle is being broken in bigger and bigger segments. I believe this means that the engine will calculate the orbit as a fixed number of points, at fixed time intervals. And for very long times, this approximation becomes evident

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Until the very fast (at least compared to a 1.7 million years orbit) part close to the sun doesn't even look like an orbit anymore

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and then it becomes hyperbolic and returns to normal

Here, though, I realize that I will be touching Kerbin only twenty days after the DREAM BIG. And the way I will gently touch Kerbin's orbit results in a relatively low intercept speed - 3000 m/s, an enormous number in normal times, but if you consider the kind of trajectory Dolphin 3 took, and then you consider that Dolphin 2 had 11 km/s... Fuel supply would be all right for the rendez-vous, with enough left for exploring the moons and a good safety margin. Perhaps with some extra manuevers I could dock with the DREAM BIG again? I was already in a conundrum on whether to detach the Can during the flyby, but i'd have rather kept 6 people on board. This would solve the problem neatly. I don't have to postpone exploring Mun, I can evacuate those kerbins that suffer worse from radiations, and I can keep my last two dolphins.

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It only took 160 m/s to reach Kerbin at the same time

Here I am also hit by another glitch I was afraid of. Ship data said my oxygen would last 6 years. Indeed, some quick calculations confirm that. But now, less than halfway through the trip, i already lost 30% of my oxygen! Should have been 5-7% by calculations.

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Probably it has something to do with the solid oxide electrolysis (a process to recycle oxygen from CO2) while the ship runs in background at high warp speed. Well, if it keeps up like that, I will still reach Kerbin, barely. However, by this time I was turning on the shield on the DREAM BIG, so I had no need to select it. And once I started traveling with Dolphin 3, the problem magically disappeared. I still had 70% of my oxigen upon reaching Kerbin.

With no more worries from solar storm, the time goes by fast. And the final approach comes. This is going to be even more difficult than docking the DREAM BIG while escaping from Jool. This time I also have a very final deadline if I want to be able to stop at Kerbin and reach the moons (docking after Kerbin and dropping the lander on the next flyby in two years would certainly be easier, but less satisfying. And I have Jeb with 83% radiation damage, he needs to see a doctor). It took me some 5 tries before I managed the rendez-vous right, and still far enough from Kerbin to manuever before periapsis.

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I must slow down gradually, while trying to keep my speed pointed straight towards the target. But not too gradually, because I also want to reach the DREAM BIG before Kerbin periapsis, with enough time to do all the docking manuevers and then slow down for capture

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There's no way to get a close approach marker here. I can only trust the navball

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Success! The DREAM BIG is there, and still 20 minutes to periapsis

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Year 11, day 330, Dolphin 3 rejoins the DREAM BIG. For about one minute. The crew is still quite healty, they stay on the mothership. Dolphin 3 picks up those with the worst radiation damage. And some extra food, oxygen and water, just to stay safe.

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17 minutes to periapsis. Undocking from the DREAM BIG, picking up the Can. This feels like a racing car pit stop.

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Docking is made more complicated by the Can getting stuck on the mothership. To those smaller crafts it is not just a space station, it is an entire landscape

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Finally, docking is done. Now there's just enough time to turn just enough for aerobraking!

Yes, aerobraking. After all this time I haven't learned! I exploded the marco polonium skimming the atmosphere of Jool, I exploded the flying christmas tree trying to aerobrake at Laythe, I exploded the DREAM BIG at Duna, but I STILL KEEP BEING NAIVELY DUMB OPTIMISTIC ABOUT AEROBRAKING!

Ok, it wasn't that bad. Dolphin 3 has a big thermal shield, indeed the return module survived a 9 km/s reentry. And I assumed the Can would be much more draggy, so it would go backwards. Correct. And I assumed the Can would be covered by the shape of the Dolphin. Also correct. And I assumed I could do a quick EVA to move the solar panels in a less exposed position. The only exposed part are the engines, and they are quite resistant, especially when they are not taking the full impact. Here is where I go wrong. the gas tanks on top of the engines are also exposed. And they have a lower thermal resistance. They exploded as soon as things got heated (literally), and without xenon tanks my nice dolphin could be renamed oyster, for it would have the same ability to move. And I can't move the tanks because they are modded parts.

And then i also broke the engines. Just as a reminder that indeed I was exceedingly optimistic. Sure, I entered Eve with an engine exposed, but i was moving at 3200 m/s from a low circular orbit and i did it very gradually. Here i am at 4000 m/s and I am going deep in the atmosphere to lose 1 km/s in one single go.

So, I have to rocket brake. Ok, I have some 2 km/s, I only need 1.

Or at least, I would need 1, if I had a chemical rocket to use oberth effect. As it is, I am slinging past the planet so fast, by the time I stopped I was already close to Mun.

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At periapsis I use some of the Can's fuel to take advantage of oberth effect. With limited success, since the Can also has no thrust to speak of. Awful lander.

All I can say in my defence is that making a light, simple rover design with multiple engines redundancies is harder than it looks like

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Finally, with less than 1 km/s (yes, this time the game calculation is correct), Dolphin 3 gets captured by Kerbin's gravity. It must use the little remaining fuel to orbit both moons.

As for the Can, it has 2100 m/s when full. I spent about one third of its fuel to brake, I'm not sure if I still have the 1700 required for both landings, and through how many hoops I will have to jump to make it suffice.

10.4) To do things backwards

Spoiler

At least from a high elliptic orbit it's not too hard to reach Minmus, if one knows some unconventional routes. It's almost like a bi-elliptic transfer, only less elegant.

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24 m/s for intercept, 200 m/s for low circular. I may save some more if I lowered apoapsis to Minmus level with approach on another orbit, but i'd have to raise my kerbin periapsis because i'm currently going to hit the planet.

after making a full grand tour (albeit a somewhat irregular one, what with all those shuttles detaching from the main ship), landing on the two moons of Kerbin is easy and not worth mentioning. Unless someone happens to be very short on fuel. Anyway, Minmus landing

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Low cost transfer to Mun

Mun is the easier target and the first celestial body any new player visits. Only fitting that I would visit it last

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I am really short in fuel. This lander with its low thrust is not cooperating. Maybe I should have removed the landing legs again

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Not enough thrust! Now I crash!

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Wut!?!?!? I bounced!

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And now I stopped, and I saved fuel!

Ok, let's talk a bit about this successful lithobraking. First, I crashed several times into Mun. Into Minmus too. I'm not used to a lander with such low TWR. It's hard to time a suicide burn correctly with low thrust.

I first bounced on Minmus. And I was going even faster, 90 m/s. And I took no damage. That time, though, I wasn't ready to snap pictures. And this time, I took damage. You may notice 3 engines are missing.

It's not surprising to survive a 100 m/s impact. My time driving the Dancing Porcupine rover thaught me that landing struts can take a lot of punishment, as long as it's glancing blows. Smash into a rock wall, you die. Fall down from some height, you die. But skim the surface at high speed, barely touching it, and you'll bounce. So, not entirely unexpected. Still, I would not try to replicate this manuever, unless I was really, really, really desperate. Even then, removing the landin legs for weight saving is probably more efficient than using them for lithobraking.

Anyway, with 3 engines down the Can still has enough thrust to get orbital again, and now it also has enough deltaV. I only have to turn this capsule upright first. Redundant reaction wheels make this possible

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I have to give one thing to the Can. I designed it with a concern for engine malfunctions. My primary objective was to design a lander that could lose a couple of engines and still keep flying. And look, it lost three engines - all on the same side, no less - and it's barely noticeing. Perhaps it wasn't such a bad lander after all.

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Rejoining with Dolphin 3

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The return manuever to Kerbin. Since I am on a polar orbit, I must wait the correct alignment to return cheaply. Good thing Mun orbit is just 6 days

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Aerobraking needed a couple passages to slow down before it was safe. Do notice the fuel left. Dolphin 3 started the mission with 15000 m/s and is now down to 150. The Can had 2100 and it's now reduced to 24

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My last worry was that the parachutes, upon opening, would flip the ship around so violently that they would break something, like the Diggers on Duna. The opening was indeed violent, but nothing broke

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Year 11, day 369: Bill, Jeb and Pendatte are safely on Kerbin, where some specialized doctors will treat them for radiation poisoning. They spent over ten and a half years in space

In the end the Dolphin, designed as a humble escape pod, proved itself capable of far more. It led a manned mission back from Eeloo at high speed, it managed the craziest rendes-vouz I ever tried so far, and it ushered the Can around the Kerbin system. Indeed, it should be possible to make a kerbalism grand tour as a relatively simple mission with a marginally expanded Dolphin design

Of course I could just recover the Dolphin's reentry module, but it feels better to recover all. My kerbin scientists will gain a lot of insight on how vehicles survive space weathering over a decade if I bring down some intact pieces

With this, I have visited every remaining celestial body in the Kerbol system, and I brought half the crew back home. I could have just evacuated the remaining kerbonauts during the during the kerbin flyby, achieving complete success. But I am now trying to recover the ship, to achieve outstanding success. Of course, I can still get a partial failure if my remaining kerbals die, but at this point it's unlikely.

Edited by king of nowhere
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  • 2 weeks later...

Part 11: No thing left behind

DREAM BIG makes it successfully back to Duna. Digger 1 and Digger 2 are successfully recovered. The fully reunited DREAM BIG successfully returns to Kerbin and lands the remaining crew; practically everything of the original ship is still fully functional, or it was recovered. The mission achieves outstanding success rating.

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11.1) Jool-Duna in 9 years 394 days

Spoiler

Last time we heard from it, the DREAM BIG had made its first Kerbin flyby, and was heading for the second. It has some 900 m/s left. I had established a second flyby was needed to reduce solar apoapsis enough, but i was still uncertain on the trajectory afterwards. Well, the easiest way is to wait in my parking orbit until the celestial mechanics, aided by a small correction manuever, align me with Duna. There is a problem with that, though: I would hit apoapsis just behind Duna.  And the orbit after that i'd be too far from it to reach the planet in a reasonable course correction manuever. And the next orbit, too. I'd have to catch up with the planet again, which would take 3 or 4 orbits. It's a lot of years.

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First solution: Kerbin flyby lowers apoapsis to meet Duna there. I miss Duna on the first orbit, I can meet it again in 3 or 4 orbits. Intercept speed will be about 600/700 m/s, leaving 200 m/s for course corrections. Safe, but slow.

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A refined version: Kerbin flyby, then at apoapsis a periapsis-lowering 160 m/s manuever sets me on course to meet Duna three orbits later, with an intercept speed of 750 m/s. Total cost 900 m/s, I can save 200 aerobraking. Good safety margin

The alternative is to try and catch Duna on the first orbit. I will need to go faster for that, which can be achieved with a lower periapsis. I will then need an apoapsis-raising manuever. Of course, this will result in a faster intercept.

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250 m/s apoapsis raising, and 850 m/s to capture, and I can reach Duna immediately

Total is 1100 m/s. I have 900 m/s and I can aerobrake for roughly 200 m/s. It's close. It's really close. So I must choose between one safe trajectory that will have me orbiting Duna in 5 years, with 200 m/s to spare, or one risky trajectory that will reach Duna in just 1 year, and once there I'd burn all my remaining fuel and hope that was enough to not disintegrate in the atmosphere. Do I have enough deltaV for the fast trajectory? Do I feel lucky?

Well, that's the wrong question. The real question is, do I actually need to take the fast trajectory? Let's see:

- food and water stores fully support waiting. Nitrogen is starting to run low, but I can't refill nitrogen anyway.

- I have to wait Digger 2 back from Eeloo.

So, I don't really gain anything by forcing a Duna encounter early. I still have to wait Digger 2. Slow route it is, then.

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Kerbol is again at maximum activity, but with the shield online, that's of no concern either

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Final trajectory. Planned arrival at year 18

And that's basically it. For 5 years I don't have to do anything about DREAM BIG, besides one maintenance tour midway through the trip and another one after arriving at Duna.

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Course correction at solar apoapsis

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Sending out an engineer to check out all the systems

During the trip, I lost a shield to a nervous breakdown. Oh well, I have 130 of those. I also lost some nitrogen, that's a greater concern, but I have enough to finish with years to spare. Finally, after a long pause while I was dealing with Digger 2 (in its own section), the DREAM BIG reaches Duna.

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Rocket braking before the atmosphere. The idiosyncratic use of some groups of rocket is dictated by the fuel tanks bug; here I run out of fuel for the lower engine pack

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Aerobraking; the manuever node was set to 0 before and it keeps track of how much I am decelerating in the atmosphere

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turns out the DREAM BIG could shed 250 m/s. Perhaps the fast manuever was viable after all

Year 18, day 94, the DREAM BIG is safely orbiting Duna, 9 years and 394 days after starting all the manuevers to leave Jool (counting from the moment I detached Dolphin 1 to protect the crew from radiation while I sent the DREAM BIG around Tylo). And all because I was missing 200 m/s.

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And one more round of maintenance in the narrow tunnels of the ship

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This final picture details my remaining resources upon reaching a stable orbit. I made it with 50 tons of fuel left, but now I can get more. I still have half of my hydrogen and oxygen stockpiles. Water is not very representative, since I regolate its amount with fuel cells and electrolysis. Food is starting to be short, but I can reactivate the greenhouses. Many years of kerbonauts breathing filled again my CO2 stock. I am down to one third of my starting nitrogen, though. Ammonia supplies won't last long once I reactivate the greenhouses. As a reminder, I can mine water from Ike, and I can get CO2 from Duna's atmosphere, but nitrogen - and therefore ammonia - is in limited supply. Still, that's 17 years worth of consumption; I should have enough nitrogen for at least 5 more years, perhaps up to 10.

11.2) The long trek of Digger 2

Spoiler

Last time we checked on it, Digger 2 was on its way back from Eeloo to a Kerbin flyby. It only had 350 m/s left, but on the plus side, it can aerobrake much better than the mothership. Also, once I am around Duna I can send another Digger to intercept, so I only really need to reach Duna's SoI.

So, first thing is setting up the first Kerbin flyby so that I can get rid of inclination and I can reach another Kerbin flyby twothree years later.

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Lowering solar apoapsis enough to return to Kerbin two years later would require a 40 km apoapsis on the first flyby. The atmosphere would kill me well before that. This sets the mood for the rest of the mission, full of "almost" and "not quite"

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A softer flyby send me to Kerbin three years later. Of course a periapsis of 55 Mm will require a course correction later, but when planning so far ahead, you can't get much precision

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A shot of the greater trajectory up to the second Kerbin flyby

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To achieve the precision necessary to return to kerbin in 3 orbits, I planned a manuever for 0.007 m/s. Not even RCS can do something so accurate. I made it by setting a single engine at 1% thrust and hitting the shift key as softly as I could

Now there is the second flyby to plan. It should send me on a Duna intercept, possibly in a reasonable time.

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Option 0: the straightforward manuever. Use the Kerbin flyby to touch Duna with my apoapsis, then use a course correction to force an encounter in some orbits. But I would reach apoapsis slightly behind Duna, so I would have to wait multiple orbits to catch up. It would take something like 5 more years after the flyby. While DREAM BIG waits on Duna with its dwindling nitrogen reserves.

Doable, but I'd rather be faster. So let's try other options:

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Option 1: just like I tried with the DREAM BIG, take an even steeper assist at Kerbin, end up with a shorter orbit (red). Then raise solar apoapsis to Duna's level, and intercept Duna. Problem: I can't lose enough speed on my gravity assist alone. You can see I am planning a 70.5 km periapsis. to reach the desired trajectory i would also need 215 m/s burn at Kerbin periapsis. Then a 145 m/s burn at solar periapsis would send me to Duna. It's 360 m/s, and I have 347. No, I tried to refine that trajectory better, won't work. I need to brake by that amount for the red orbit to be syncronized to reach Duna. And I need that amount of apoapsis raising afterwards because that's required to raise my apoapsis enough to touch Duna.

Option 1 does not work, for lack of 20 m/s.

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Option 2: As option 1, but going inside Kerbin's atmosphere. I only need to save 20 m/s, perhaps if I lower kerbin periapsis to enter the atmosphere for a few kilometers I will get them. In this new iteration, I make the manuever work with 340 m/s by lowering the periapsis to 53 km; it would leave some juicy 5 m/s for course corrections. Of course Digger 2 is too fast to aerobrake without shields, but perhaps it can survive a pass to 53 km? I normally don't even start to see flames or a significant drag until I am below 50. Worth a shot.

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Intercept speed is over 5 km/s. At 65 km I lose the first two solar panels, but it that was the only casualty, I could accept it

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Before reaching the altitude of 60 km, the ship starts breaking apart

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At 59 km, there's basically nothing left. So much for a 53 km periapsis

So, option 2 does not work because Kerbin's atmosphere is 10 km too high. I can't speed up the encounter with engines because I miss 20 m/s, and I can't speed it up with gravity assists because they would take me 10 km deeper inside the atmosphere than I can survive. Do I really have to take the long route? Is there really no other option?

One last thing to try: a Kerbin-Mun double assist!

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Slowing down by 40 m/s would let me find Mun  after leaving Kerbin. You can't get much from a Mun flyby, especially at high speed, but I only need to save 20 m/s.

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And passing in front of Mun does lower my solar apoapsis enough for my purposes! Now I can reach the parking orbit (which in option 1 was red, this time is brown) without further fuel expenditure. I can then raise my solar apoapsis for a Duna encounter with 120 m/s, and it leaves me with over 150 m/s!

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This is after the correction manuever. I need an additional 16 m/s after Mun for plane correction, all right. I can reach Duna in less than 3 years after the second Kerbin flyby. Intercept speed close to 1 km/s, don't think I can aerobrake that much, but I can send a rescue mission

So, option 3 is successful. But I have to wonder: I made all this mess to reach Duna at year 19 with a 1 km/s intercept so that I could send a rescue mission. I could instead have waited two years around Eeloo to launch in the right window at 12:259 with 1100 m/s (instead of 1400 to reach Kerbin). Then I'd have reached Duna in 17:224 with an intercept speed of 1200 m/s. And I'd still have over 600 m/s to rocket brake, so it would have been a better trajectory after all. Only problem, there still was no DREAM BIG around Duna to help. Though there is a similar solution to reach Duna in year 19 starting year 13. Anyway, we learned two things today:

1) You can always find a gravity assist, if you look for it hard enough :cool:

2) Overthink your gravity assists, and you end up spending more than if you had just used the direct transfer :(

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Kerbin periapsis: I am slightly inside the atmosphere and you can see the drills are getting a bit red, but the disaster attempt of Option 2 taught me that I can dip up to 4 km before bad things start to happen. There is one single broken reaction wheel; Digger 2 tanked its long trip without maintenance very well, especially compared to Trucker, or the Wings probes, or its sister ship Digger 1

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The small amount of aerobraking lowered my mun apoapsis, but still at a safe level. I've never seen a Kerbin-Mun transfer in 45 minutes, although when reentering with Dolphin 2 I was even faster

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The Mun flyby was exceptionally fast, it felt like time warp was on

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The final burn will set Digger 2 on course for Duna, arriving in the second half of year 19

11.3) Recovering Digger 1 (plus, general stay at Duna)

Spoiler

The crew of Digger 1 left Dres in year 7. The poor ship has been over a decade without maintenance, and it shows

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Out of 12, there is one single heroic solar panel still working. I decided to bring it back to orbit, it would be easier to recover it if I lose contact completely. On the plus side, most of those malfunctions can be fixed.

Broken solar panels cannot be retracted, so I had to launch with the array deployed. It meant going straight up, at a slow speed to avoid breaking them, (also, I needed the antenna deployed to pilot the ship remotely) and the aerodinamic was pretty bad. I used 400 m/s more than in a normal Duna ascent, but it worked.

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Launching Digger 1 back to orbit, in year 12. Only 4 malfunctioning panels at the time.

Anyway, one solar panel was enough to keep the ship active and rejoin with the DREAM BIG

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Limping, crawling, but defiant to the end! That's a great ship!

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Don't worry baby, Giuritto will fix you in no time

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Those are broken for good, they have to go. And half a ton removed.

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Remember that Home had some extra solar panels because of a construction accident (7.5)? I used one of those to replace the broken one. There you go, 17 years in space, as good as new.

Then it's refueling time. Digger 3 and 4 alternate to land on Duna, bringing up 110 tons of fuel every time. Digger 1, the only vessel with a water drill here, takes unmanned trips to Ike to gather water and hydrogen; each one of those trips uses 50 tons of fuel. Well, I already have a lot of pictures of refueling at Duna, back from the first time I did it (6.2). I only took a couple more.

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Just to show that not only Diggers can fly without one engine, but they can also land without a parachute

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Things to do before dieing: night shot of Duna's atmosphere Done

Refilling the tanks completely would take a lot of real life time, I don't want to do it again. This time I only load 800 tons of fuel, enough for 1300 m/s, a more than safe margin to go back to Kerbin.

Radiations are again a problem. Turns out, Duna's magnetosphere is irregular and does not fully cover the orbit. Sometimes I am exposed. And I cannot leave the shield always open because my batteries won't last through the night. I did the best I could with automated options (turn off the shields when low power, turn on when high power or when irradiated). But between sun/night trigger working imperfectly and time warp making for rounding errors, I still got mildly irradiated. Around 5% in two years, which is still a net improvement over the first Duna stay. If I could go back, I'd pack some more batteries on the DREAM BIG, so that it could keep the shield online through the night.

Or perhaps I would rearrange the solar panels so that they would be irradiated while the crew is shielded, and then I would ditch the shield entirely. It's great to have, but perhaps not worth all the trouble it makes.

Anyway, the DREAM BIG is now ready to grab Digger 2 once it shows up, and then leave for Kerbin at the next transfer window.

11.4) Recovering Digger 2

Spoiler

Digger 2 is approaching Duna at high speed. I'm not sure how much a Digger can really aerobrake, so I try it, without much hope.

Well, turns out, it holds up pretty well. It did reach stable orbit. But it lost 2 solar panels. I could accept that outcome, if I didn't have a better strategy. Wait, I do. I sent Digger 3 to the rescue

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Digger 3 times its orbit to meet Digger 2 at Duna's periapsis

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They are going to pass very close to each other, but the intercept speed is very high. I need to slow down in advance, and this makes the capture less accurate

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Digger 3 managed to pass periapsis before Digger 2. Now it needs to wait for its sister to catch up

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Digger 2 recovered! It really survived very well its 8 years in isolation. Compare with Digger 1 in its liftoff shot, that was after only 6 years alone

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There is still the little problem that the two Diggers are in an escape trajectory. There is enough fuel to make it back. Actually, deltaV reading on the stages is wrong, and this is the first time when I see it being overestimated. Still enough, barely

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Rendez-vous with the DREAM BIG, now let's dock everything in place

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The FU Eve takes back its place

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Here for the first time I am trying two dockings simultaneously

11.5) Outstanding success!

Spoiler

Now that every single shuttle has been recovered, all is left is the trip back. First I must wait one more year for the launch window. I launch at 20:277

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I decide to use Ike for a gravity assist, mostly for training as I just learned to use moons for small helps on fast trajectories. It saves 50 m/s

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Using the rhinos for more precision

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Ike flyby

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After 300 days of uneventful travel, I'm back on Kerbin. Capture burn.

I am down to 25% of starting nitrogen. I could have stretched the trip maybe 5 more years. I am also not particularly large in oxygen, hydrogen and food, but that's only because I cut short the resupplying trips at Duna. During this time there were some more breakdowns, but they all resulted in malfunctions that could be repaired, so no permanent damage was suffered.

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Stable orbit reached. Now to land the crew

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I decide to try and land a Digger

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Unfortunately, it turns out Diggers don't have enough parachutes to land with those alone. Digger 3 hit water at 11 m/s (including rocket braking, the wolfhounds don't do much at sea level) and killed the crew. Reload

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So I use a Dolphin. Only 1, I will try to land it whole. Hey, it did the trick with the Can

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Turns out terminal speed for a whole dolphin is still too fast. The Can survived because it had heavy landing gear.

What the hell, those things were never intended to try to land with the full habitation module!

Reload again?

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I am on water, and kerbals are made of iron. So I decide to get three of them out of the crew pod. They survive the dive all right. The other three stay inside the command module, it's sturdy and will survive the impact

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Everyone safely on Kerbin!

It's 21:115. The mission started on 2: 150, so the crew spent 19 years 390 days in space. (And I spent over 2 months of real life time, using most of my free time on this game - because, with the quarantine, not much else I could be doing.)

Almost 20 years of breathing, eating, drinking, getting stressed and breaking up stuff, being bombarded by deadly radiations, and the DREAM BIG kept them alive through all of that, and it's still fully functional. I am proud of that ship

From the original mission objectives:

On 12/26/2020 at 5:55 PM, king of nowhere said:

1.11) Goals and success

Outstanding success!

Grand tour is completed successfully; DREAM BIG returns to Kerbin and it’s mostly in good conditions, ready to make the trip again with minimal resupplying.

Well, I landed a kerbonaut on every celestial body (though it was pointed out that i didn't fulfill a technicality, my fault for misreading the rules). I brought every kerbal back to Kerbin. The DREAM BIG is also back to Kerbin, and it only broke a handful of pieces. Actually, it survived the trip in much better conditions than I was hoping for. I didn't even need most of the redundant contingencies.

And every ship was recovered. The Diggers are all there, all fully functional, maybe missing a single reaction wheel. One Dolphin is still there, one made a reentry, one landed whole, the last one landed semi-whole. The Can was recovered - minus the Tylo descent stage, which was always intended as disposable. Trucker was recovered.  FU Eve was recovered, at least the part that went back to orbit. The Wings were not recovered, but they were fire-and-forget probes.

There was some lack of elegance in sending some Diggers to Dres and Eeloo alone and not recovering the crew for the rest of the trip, but all things considered, I claim confindently that the mission was an Outstanding success.

Whew! I wasn't even sure this ship would be able to fly when I started all this.

Edited by king of nowhere
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On 2/28/2021 at 9:42 PM, RealKerbal3x said:

Now go do something easy in KSP for a while! :sticktongue:

Nah. Boooring. I need challenges.

My next one is another grand tour with kerbalism, this time without isru. which is actually easier, as i will use ion engines and a lot of xenon. since it would become too easy, i decided that part of the mission will also be taking samples from at least two biomes on every planet, and i will do it at hard level, which increases failure chances and reduces radiation shielding effectiveness. But now that I discovered how to enable the radiation decontamination unit, i should be able to visit the jool moons one at a time, then retreat at a safe distance and heal my crew before going in again.

that mission is also meant to test the effectiveness of the tv to reduce crew stress. if the mission shows it's viable, then the next mission is another grand tour, with isru, with the full kerbalism rules. it will entail landing a 3000 ton beast (which i already made, it has all the fuel tanks on the outside to protect the crew from radiations from multiple directions) and waiting there until it refuels with the slow, slooooow kerbalism isru. if my calculations are correct, one such refueling should take 90 years. as long as i have enough solar power - as far as duna's orbit, basically. i don't know if that plan is viable, but if i can keep stress in check, i definitely want to give it a try.

i will make new mission reports once the missions are on their way

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I have an idea, deploy a Elcano capable rover(use bon voyage) but only keep the Kerbals in there one day on each planet. I'll use ions(cheaty) but I'll give you seniority for the achievement. I just have to finish my SSTA mission(in stock) and then download Kerbalism. For laythe a hypersonic plane to minimize rad exposure. Tylo, a realld low orbit for surveying and an unmanned rover.

Edited by Single stage to ocean
I had a new idea.
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3 hours ago, Single stage to ocean said:

LOL what if you land home on kerbin with parachutes.

I actually considered it. enough cocoonators should let it survive atmospheric reentry.

i decided against because it's not a ship made to land and be retired. it's made to last. in fact, it was so enduring, it could easily perform another grand tour if i only sent up another eve lander and small lander. on the other hand, if it landed, it could only go in a museum. so i decided to leave it in orbit, because it's still young and strong.

Also, with the lag and the necessity to dock dozens of cocoonators, it would have taken days to manage a landing.

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You could "steal" someone elses EVE SSTO(give credit of course), add more parachutes to the dolphins, and use orbital docking and rocket SSTOs to launch Home and the shuttles up there fully reusable. (Part count can **** itself). I have the advantage because I have a good desktop. (No bragging). And to answer you, when Home starts having permanent damage, I would have first fixed it with EVA construction, when its too late, I escape with a dolphin and then, use home unmanned, or if it is immobile, send an ion fast ship to recover it and use it in a museum. I might also maybe adapt it as an Minmus-Mun crew transfer perhaps. Extra points if I launch it again after some on Kerbin "refurbishing"(really just sending an army of Kerbals and using the EVA construction assist feature to take off all the broken parts and add new ones back. The shuttles can stay in orbit and the solar panels can be sacrificed during re-entry.)

I plan to start a thread where you have to do the fastest grand tour in Kerbalism, and I have a concept a Ion powered fast ship called "Nucleus" with adaptable Lf-Ox shuttles called Electrons that can land on any planet as an ssto. It will also have some escape pods called Kepler and some support vehicles called Galileo(or "dust bugs"). For Jool I'll use a ship called Katherine(you know who its named after) with full shielding and ion engines to force super quick planetary transfers.  I'll land unmanned rovers(for science and for PR, expensive missions don't do well unless science is done) everywhere and try to do a circumnavigation of each planet(really just a super low orbit on the vacuum worlds and a hypersonic plane for Laythe and Kerbin.) For Duna an ion glider will do the trick(extra points if I return to orbit.) Might take a year but it will be spectacular.

Edited by Single stage to ocean
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Part 12: Post-flight ramblings

Looking back on the mission and on the mod. A final closure

12.1) DREAM BIG cinematics

Back at the beginning, when I was en route to Eve, I took a recording of a spacewalk around the DREAM BIG, before it started to drop stages. I knew I wanted to turn it into a cinematic, but i never put up the time and effort for video editing until now. Part of the reason was laziness, part was that before presenting this as "the ship who made a kerbalism grand tour" i wanted to actually make sure that it would manage the grand tour in the first place. Anyway, I hope you'll like it.

12.2) Kerbalism review

Spoiler

Now that I used it extensively, it's time to express some opinions on the mod.

And I'll start by saying that it's definitely a great mod, and it does indeed enhance the feeling of a "realistic" mission. I definitely would recommend it to anyone who's looking for an extra challenge. The fact that the mod is not made to make things easy is exactly what makes it appealing.

The mod is quite hard to learn, and the guide will miss on most details. On that, it's no worse than the stock game, but it's easier to find guides, tutorials and answers about the stock game. Not sure there is really anything that can be reasonably improved here, though.

There were a few bugs along the way, not sure how many of those were connected to the mod and how many to the stock game. In any case, when you have a 1300 part ship and you run it over 20 game years without irreversibly crashing the game, it's already a big success.

Now, though, a few things that i think could be improved.

- I appreciated the stress mechanics. It feels real to have stuff go randomly bad from time to time. However, as currently implemented, stress just punish you from bringing more astronauts. Bringing more is already a considerable investment - the DREAM BIG could have been renamed DREAM AVERAGE if i had contented myself with a crew of 3 or 4 - in that they require life support and 20 cubic meters of habitat, with radiation shielding. In addition to that, they also increase the number of breakdowns. I think more kerbonauts should decrease the likelyhood of stuff going wrong, because they can double check on each other. In addition to the normal breakdown messages "Jeb has opened the wrong valve, [stuff] was lost" or "Jeb was possessed by a blind rage, [part] has been damaged", I would like that bringing extra crew would sometimes give you "Jeb has opened the wrong valve; luckily, Val realized the mistake before it had dire consequences" or "Jeb was possessed by a blind rage, but Val could calm him down".

- heat management is unsatisfying. On one hand, you never, ever need radiators. Even when you're around moho and your ship should get heated to over 300 degrees, everyone is fine. Ok, i assume any crew cabin has built-in air conditioning, but the heat must then be vented somewhere.

More important, heat death happens way too fast. It happened multiple times that upon time warping, I would suddenly find the crew dead - because a battery run out during a passage behind a planet, and then the ship started to cool, and all kerbonauts froze before the ship reached the day side again, and it all happened so fast that the game didn't have time to exit time warp. Which is just no. A spaceship takes far longer than that to heat/cool to a dangerous level. Especially one this big, with lots of thermal inertia.

Speaking of heat/cool, a ship should spend some energy to stay warm in the outer system. I haven't noticed this happening. (later EDIT: it does, it's just a small amount compared to everything else)

- radiations were the big scare of the first attempt, but once I knew them better, they became sort of a paper tiger. A single z-4k battery standing between the sun and the habitation module - coupled with avoiding excessive time warp, something that nobody mentioned - was enough to completely negate solar storms. After investing in 120 active shields, it felt kind of a let-down. My crew traveled 20 years, of which over 5 without the shield, and in all that time they didn't get a single % of radiation damage.

At the same time, Jool's death zone ignored all of that. Ok, inside a radiation belt radiations are coming from every side, I get it, but if my crew cabin is surrounded by fuel tanks on every side, I should still be protected. Then again, maybe it actually happens and I didn't notice some small difference in radiation between Diggers and Home (EDIT: no, there is no difference, the game does not model any kind of occlusion inside belts). Anyway, not sure what I would do there, but I feel it could be rebalanced a little. I also haven't noticed any actual effect of radiations on ship parts, despite years of traveling at solar maximum with the shield down.

- automated routines: kerbalism has some automatic commands that can be set to start/stop processes on some conditions, like high battery, low battery, exposed to radiation, or a bunch of other conditions. Those are a real life saver, there's no other way to deal with time warp otherwise. Yet they can be improved. One thing I would have liked would have been additional battery settings, so that i could shut down non-essential processes way before battery charge becomes an issue, and reserve the 20% battery for emergency measures.

But more important, I'd like to be able to set automatism based on resources, because it made some problems. When the Diggers were mining duna, they had to pass the night with fuel cell power. this produced water. To avoid wasting that water, in the day the water would be electrolyzed, so there would be again hydrogen the next night. Problem is, the routine would electrolyze all the water, and then the crew would have none left. I had to go around this by carefully balancing the amount of hydrogen in the tanks, so that they would fill before running out of water. My future plans for more advanced isru are facing this problem even worse. So, adding a condition "water 20%" to stop water electrolysis there, or adding a caveat on the electrolysis reactor "do not exhaust water completely" would be of great help.

- reuse of resources was kinda depressing when closely analyzed, unfortunately. I mean, ok, doing that stuff is complicated, I get it. But one big progress in space we made through the decades is that we started to reuse more and more stuff. The Apollo crew would breathe from an air tank and the CO2 would be absorbed chemically. their waste would be chucked overboard. Nowadays instead we process the CO2 to get more oxygen out of it, we process the waste to get water out of it, and so on. That stuff should be convenient.

But in kerbalism, it's often not the case. Waste recycling gives back practically nothing. Same for water recycler, it's as heavy as it is inefficient (later EDIT: actually the water recycler is very efficient, I got fooled by other mechanisms of water loss). But the cake goes to the greenhouse: I run the mass calculation, and it takes much more than 1 kg of resources to make 1 kg of food. Which is all normal, but then your kerbal eat the food, craps, and you reuse that to run the greenhouse. But even detracting the resources you can recycle, it still takes over 2 kg of resources to make 1 kg of food. So, greenhouse+water recycler+waste recycler are actually trap options, and you are better off just loading more food and venting everything in space. And that's before even counting the weight of the greenhouse.

I think resources recycling should be made more efficient. Of course there should be no 100% recovery, you never get 100% in reality, but recycling should be actually convenient. On the other side, pressurized tanks should be heavier; part of the reason recycling is unoptimal is that carrying more is so cheap. They are big metallic tanks that must be thick to resist pressurized gas, they are heavy.

- isru is surprisingly balanced, I run some calculation on solar power output and energy needed for some processes, and it actually fits. But finding resources is way too hard. There is close to no water on Minmus, despite it being described as a slushball. There is no water on Pol and on some other joolian moon, despite water being the single most abundant compound in the outer system. Carbon is not available anywhere except in some atmospheres, and ok, carbon is not very abundant on rocky planets, but there are sources of it. And you need carbon to make fuel, which limits you greatly. Wherever there is water you can get fuel as LH-LOx, but under kerbalism that's not possible. You can only get fuel at Duna. You could get CO2 at Eve, but there is no water anywhere on that planet -  which is crazy, because there are oceans on it1.

So, isru high requirements in energy, time and machinery are entirely appropriate. But the necessary resources should be more readily available.

1 There is a claim that the oceans of Eve are made of hydrogen peroxide. This may be the intention of the game designers, but it is completely ridiculous to anyone who knows anything about hydrogen peroxide. Even accepting that, though, you still can get hydrogen and oxygen out of it. Hydrogen peroxide is also inappropriate as oxidizer in rocket fuel; it was experimented, but it was way too unstable for use, and not at all energetically convenient over the alternatives. Or, Eve's oceans could be made of hydrocarbons. Which would be even better, you still can get hydrogen out of them, or you could burn them for fuel directly.

12.3)  ship review (and preview of future missions)

Spoiler

In chess, after a game, it is advised to look back at the game, to find mistakes and opportunities and learn from it. I've been playing chess since i was 7, so looking back on the mission amd wonder what could be improved comes natural. I hope it won't come as too self-referential. So i'll give a report on every module of the DREAM BIG, as well as on the flight plan itself

Dolphin :rep::rep::rep::rep::rep:

The Dolphins definitely earn top marks as the single best performing ship among those I used. They started as escape pods, and are extremely efficient at that, but they also turned out to be very capable long-range transports. I would hardly know how to improve them. Just two small things, I would add a small tank for carbon dioxide. Not because it's needed, but because its absence caused a glitch with the solid oxide electrolysis that caused the oxygen to not be recycled efficiently. And I would remove 400 units of ablator from the heat shield, it's not necessary (those units were left after the high speed reentry) and it would make the ship lighter.

Digger :rep::rep::rep::rep::rep:

Diggers were also performing well above expectations, showing endurance and adaptability. But they had room for improvement.

For once, I'd pack more food and water in them. Their main limitation to making long trips was their limited food supply, because they were not supposed to make long trips. Then I'd especially add water capacity, because the fluctuations of water level were causing problems running the fuel cells efficiently (see the part about automated routines in kerbalism review). I'd half the number of ore drills, they were too many. And I'd put a couple nitrogen drills in their place, I felt the lack of nitrogen mining capacity. I'd try to streamline the profile better, because aerodinamic losses were still a thing, and I'd move some instruments inside the side compartments on the landing pod, to further improve aerodinamics. Finally, I'd add a couple of parabrakes, as the direct opening of the main parachutes was a very violent even that threatened to rip the ship in half every time.

Quite a lot of changes for something that got top marks, but they are all minor ones.

Home :rep::rep::rep::rep::rep:

Home was designed to provide life support and logistics, and it performed its task wonderfully. It had an inordinate amount of built-in redundancies, way more than I ended up needing. It definitely can last a lot of decades. So it gets full marks. But it could be improved  a lot. In fact, it was improved along the way, as I had to go out and do some eva construction to reshape Home to resist storms. If I were to remake it, I would do it in a way that would not need reorienting. And some crew compartments were way bigger than needed. And... well, it's easier if I share the project of its successor, the Keep Dreaming Big

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The Keep Dreaming Big takes full advantage of the lessons learned in this mission. It has 1000 m/s more than the DREAM BIG, it has 60% more solar energy, it withstands storms better, it aerobrakes better.

So, when will I be launching it? The answer is, unfortunately, never.

As far as this mission was fun, repeating it with an even more capable ship would be too easy now. Furthermore, with even more parts than the DREAM BIG, the Keep Dreaming Big would be even more laggy. Not going to put up with that again just for a slightly improved rehearsal of a mission I already made.

What I will be piloting instead is this

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It's called Nail, although the nail shape will become more evident when the lateral boosters of the Eve lander are dropped. It only has a crew of 4. It uses no isru whatsoever, but it has supplies for over 20 years, and ion engines with a ridiculous amount of propellant. It is much smaller than the DREAM BIG, but about as expensive for all the xenon gas. The nail head in the top is fuel tanks, they are to be oriented towards the sun for radiation protection, dispensing with the need for hundreds of tons of shields. Nail also aims for a grand tour, with the additional challenges

- hard difficulty level (except that saving/reloading is still enabled)

- crew of 3 in every landing

- two astronauts must land everywhere

- must visit and collect ground samples from at least three biomes, on each planet

- must find the green monolith on every planet.

For this, the regular lander is a modular lander-rover thing, while I prepared 3 disposable planes for the main planets with atmospheres (including Kerbin) and two disposable unmanned rovers for Tylo and Vall, which I won't be able to explore with humans because radiations. I plan to deal with Jool radiations by scouting one moon, then retreating at a safe distance, healing of radiation damage, and going in for another moon.

If that mission goes well and proves survival for decades, then I plan another mission using the full kerbalism ISRU rules. After I kept complaining how unmanageable they are. This is the temporary project of the ship

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At 3000 tons it's somewhat smaller than the DREAM BIG, but still huge. It doesn't have the shield, it needs all its energy for isru. It has enough thrust to land and take off from Duna. It has mining capacity to turn ore and water into fuel, at a very slow pace: if my calculations are correct (and I really hope I made a mistake by excess) it should need 90 years, if fully powered (the limiting factor is how much ore the convert-o-trons can process, and i have 9 of them). Which it will be as far as Duna. It will have a rover underneath that can mine water, in case there are no ore and water in the same biome.

The living space is all on the inside of those fuel tanks. Crew will be 4 people.

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This setup ensures that upon landing, the crew will be protected by solar storms regardless of the sun's position in the sky.

So far it's 400 parts, but it still lacks a lot of utility, like all the pressurized tanks. They will have to be a lot, because this thing will need to survive on Moho during the full 100-day night on battery power.

A hard exterior to protect the soft parts reminds me of a turtle, not to mention the round shape when seen from below. So, this is tentatively named A'Tuin

The objective is to live completely off the land. This time I have the whole set of drills that should let me regenerate all my resources. Only problems are breakdowns and real life time - because 90 years at x1000 warp? May be a bit too much.

Trucker :rep::rep::rep::rep:

Trucker is a curious case. It was very functional and it did really well. I can't really improve on it. On the other hand, it had a simple task, ample means to fulfill it (I mean, 22 km/s on ion engines? That's close to cheating), and it just feels something is missing.

With what I learned during the mission, I think Trucker could be skipped entirely, and a Dolphin used in its place. Home would then be equipped with an extra xenon tank to refuel the Dolphin after they reunite.

FU Eve :rep::rep::rep:

Here we come to the less functional stuff. The FU Eve was pretty bad. Bad aerodinamics, bad staging, bad contruction. Using the old Laythe lander as a last stage was ill advised. Bad drag from it. And going from three-fold to four-fold symmetry meant the ladder had to take weird angles, and I almost was unable to get my kerbal back inside. Piloting it was a nightmare. Nail has a much better Eve lander (still unnamed) which is lighter and cheaper and yet has a higher payload to orbit, and it includes an airplane. Well, if that mission kicks off I will post it, and you will see first hand all the improvements I did there.

Still, the FU Eve gets 3 stars, for a simple reason: it worked. And on Eve, just barely working is enough to warranty at least 3 stars.

The Can :rep::rep::rep:

The poor, poor lander without thrust. So harangued for his lack of good engines. And its insufficient electric system. Yes, it definitely needs working on. Finding an appropriate engine to maintain redundancy was complex, but I noticed the "Cub" vernier was exactly what it needed.

The poor Can still gets 3 stars for the same reason as the FU Eve, in that at least it did what it was supposed to do. But in addition to that, it was actually a pretty decent craft. It lithobraked successfully. It made a perfect landing on Tylo at the first try. It lost 3 engines and it kept working just fine. It was small and cheap to operate. So, not all that bad. It was like a car without engine, but a pretty good car if we just discount that "small" flaw.

Wings :rep::rep:

Those are the least successful of my shuttles. Deployed on Duna, they immediately failed to work properly for lack of solar power. They managed to make an orbital survey on the resources of Duna and Ike, but they were riddled with problems from the beginning. Wings 1 then broke both solar panels and stopped working within a year.

They get two stars instead of 1 because Wings 2 heroically clung to life after being abandoned at Duna, and it was still active after the main mission ended. Compare Digger 1 losing 11 solar panels out of 12, while being abandoned three years later. Actually, Wings 2 had lots of solar panels malfunctions, but they were all fixed remotely. Anyway, after 15 years at Duna it was still active, but due to power shortages it still hadn't completed its science mission of making a particular experiment with the scanner.

Flight plan :rep::rep::rep:

The flight plan could have been better. At first I was so anxious to reach the next target fast, spending extra fuel for faster travel. After 20 years of mission, it feels silly to worry so much. And I had to wait over 1 year at Duna waiting for the launch window anyway. So, I could have sent Trucker back to Eve instead of launching straight away. I was perfectly safe around Eve.

After that, the whole mission was a history of overestimating my fuel budget and having to find creative remedies. I had to take that ridiculously convoluted gravity assist to bring the DREAM BIG back to Duna, after I spent 100 m/s more than needed in the Duna-Jool trip, to reduce time. Trying to save 1 year costed me 5 years. And I had insufficient fuel to reach Eeloo, so I had to improvise and send there a Digger too. As for Dres, I could actually have sent the DREAM BIG there and back to Duna for refuel. I had the time.

Though it's easy to be hard with myself in retrospect. I had no real idea how radiations worked, or how stress would impact the mission, or even how long hardware would last. I made a bunch or realistic assumptions.

Anyway, 3 stars because it was faulty, but it did the job.

Edited by king of nowhere
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I'm go and steal your hinged solar panels idea, if your fine(I can always have dockable main solar panels that I discard for aerobraking and some backup retractable ones. then i can redock to the solar panels.). I have a concept, an entirely fuel cell and ion fast ship augmented by solar. Fuel cells powering ions reduced the isp to 1200, but its 3x as many as wolfhounds. and I can burn in the dark! Sure, it more like 2x even removing some very overrated oberth effect boosts, but thats me being able to carry 1.5x the cargo with 1.33x the delta-v. I'm so sad that you aren't launching the one with the hinged solar panels.

But why are your greenhouses uncovered?

Tip for the eve lander, add some wings to the boosters and some seperatons, the wings should be angled so the boosters are pulled away.

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Sad news, I need 12 gigantors at Eeloo per ion engine. That is 3.6 tons, in order for a practical ship, I must have a twr of 1/100 on kerbin.This makes the engines and solar panels 1/5 of weight, nerfing the dv to 18000 when I add 1/10 of the mass of the craft woth of habitation space, shuttles, and etc. I have to do 3 kiltons of ship and 300 tons of cargo and 30 tons of thrust. doable, but painful to launch and use. Persistent thrust will be needed. I'll avoid this by stopping at jool which has 5% of power worst case, and sending lfox shuttles to eeloo. That way the main ship can have a higher twr, now I just need 6 gigantors per ion engine, allowing me to 2/3 the mass and give a 0.05 twr, tolerable now, even stuck with 4x physics warp. The fuel cell idea is now dead in the water.

Greenhouses are really intended for surface bases with near unlimted water., but I'll still use them to be fair.

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They'll be exposed to radiation in the jool system. at least some structural panels will greatly be useful, and put at least 4 emergency rtgs, but as far away as possible from the cabins, they'll power life support without sheild, and when sun is there, you can turn on sheild to negate rtg, always add a decoupler to the rtg for emergency.

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20 hours ago, Single stage to ocean said:

They'll be exposed to radiation in the jool system. at least some structural panels will greatly be useful, and put at least 4 emergency rtgs, but as far away as possible from the cabins, they'll power life support without sheild, and when sun is there, you can turn on sheild to negate rtg, always add a decoupler to the rtg for emergency.

on the Dream Big i built the greenhouses that way because when i made the ship i didn't knew how radiations worked.

On the Dream Big 2 I built them that way because they can be pointed away from the sun - and it feels right to expose the greenhouses to sunlight otherwise, even if there are no in-game benefits for it. while you are in  a radiation belt, instead, everything is equally exposed, doesn't matter how you rearrange your ship

On A'Tuin I put the greenhouses and all habitation modules on the inside, so that the landed ship is protected from every angle. it still doesn't help for radiation belts. covering with structural panels would add weight and part count and wouldn't help.

 

as for 4 emergency rtgs, they wouldn't help at all. too little energy. while orbiting jool I had 50 electricity/second, and even that was inadequate. it was barely enough to run the basic systems. greenhouses were off during that time. i'd have needed at least 40 rtg for power. And rtg lose power over time, on a 20 year mission it will matter. Well, Nail has something like that, but Nail isn't particularly serious as a concept. Anyway, Dream Big's emergency power supply are the 4 fuel cells arrays and enough hydrogen to run them for days. And then electrolysis slowly regenerates them. 

There are 64 solar panels on Home, plus other 70-odd on the various shutttles. there's no way they all fail. if they were to start failing in large amounts, i'd have used the dolphins to evacuate the crew. There are 4 fuel cell arrays for periods of darkness, one of those alone is enough to cover for emergency if the other 3 break. Plus 2 small fuel cells on each Digger and 2 on the FU Eve, that can all help in an emergency.

If somehow all this was insufficient, then there is no way 4 rtg would ever help.

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