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king of nowhere

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  1. Part 5: two giant holes

    Leaping Mantis encounters the very most difficult passages of the whole voyage, in the form of two huge holes in the ground with very sheer sides.


    It's hard to appreciate with the game perspective, luckily I managed to get some orbital pictures of the location



    After mount Stegosaurus there is this thin rock ledge I dubbed the knife edge

    This section has been the slowest progress, taking three months to advance maybe 10% of the way. The problem is, on one hand I already did one fourth of the circumnavigation, which is plenty of time to get tired. On the other hand, I'm nowhere near close to the end, so I can't summon the "just one last bit of effort and then I'm done" motivation. Furthermore, I was beginning my rss kerbalism grand tour, my biggest grand tour so far - which, given that I already have a tendency for extremely ambitious missions, is quite the achievement - and I was super excited about it. I resumed steady progress somewhere along the summer.


    mount Cratertop, a mountain with a crater on top. It has two twin peaks at almost the same altitude. It probably would have been the tallest mountain on Wal, if an asteroid hadn't intervened


    here the ravine is steep enough that you can see all the way down to the plains 15 km below

    In fact, the ravine is so steep that a bit of carelessness when planting the flag led to Bill slipping and falling down to his doom. That ravine was so steep, he could not stop. Dead for planting a flag. What an undignified way to go.



    Here the mountain crest followed a sort of S shape. I followed it. Maybe going straight would have been even more challenging?



    I much prefer those narrow ridges with steep walls. For large stretches of the road, the top of the chain was large enough that you wouldn't really appreciate being on top of a mountain. Here you can get a good view. Or at least you could get a good view, if Wal wasn't ugly.

    It was amid one such stretches of large, flattish mountain tops that I found the first big hole - which I dubbed the Trench.


    The Trench, seen from the ledge. Between perspective and poor light, you don't really appreciate that there is a 4 km deep hole in front of you

    The bottom of the Trench is at 13 km altitude. The ledge descends from a 19.8 km tall mountain, but it's already dropped to somewhere short of 17 before the final cliff. So we can call it a 4 km deep hole, keeping in mind that measuring holes is not an exact science.

    It's been an interesting stretch; mount Cratertop, the thin curving ledge and the Trench are all within 100 km of each other. Afterwards, there isn't much worth noting, and nearly 400 km pass by with barely any screenshot taken.

    I could have avoided the Trench, going around it. It certainly would have been faster and easier. But then, I could have avoided this whole mission if I was just looking for fast and easy.


    Moving down the ravine into the Trench. The slope is 60° steep. Those slopes are very dangerous; a small bounce would mean falling tens of meters before touching land again. And then upon landing you'd bounce again, falling more, and gaining more speed every time. Until no amount of roll cages can protect the rover. Easy, you may think; just avoid bouncing. Except the brakes themselves make the rover bump. I learned to always save before descending somewhere like that.

    By contrast, going uphill is easy.


    Going out of the Trench, it's significantly less steep. The cosmic alignment is also right for a nice view of Tal


    Well past the Trench, just another random location with a steep slope


    Leaping Mantis braving a 60° slope upwards


    And finally, in front of me opened the 8-km hole. Yes, that's its name. If that's not impressive enough, I don't know what is. It's a nearly cylindrical hole 8 km deep.


    Though as always, you can't really appreciate the scale


    Carefully inching down the steep walls of the 8-km hole


    The hole is so deep, it's got rocks at the bottom! Seems quite a stupid thing to say, but check the previous chapter for the significance of rocks in this voyage



    Going up, I did something I haven't done anywhere else on this planet: switchbacking!

    The most impressive feature of the 8-km hole is its eastern cliff, though (which I named the western wall because it looks west, or maybe just because I got confused). It's not strictly the steepest inclination on the planet, as a few ravines are roughly as steep (most impressively mount Thor, which will be shown in a later chapter). But it is the most steep east-west ravine, and the longest, with over 7 km of near vertical climb. To the point that despite Leaping Mantis extreme climbing skills, I actually had to stop going forward in some points, and start switchbacking. Even when I could go forward, the ravine is long enough that I run out of battery many times, and had to stop and recharge. Something else I never needed anywhere else.

    It took nearly one hour of game time to cross this handful of kilometers.



    Those two pics show the highest limit of vertical climb Leaping Mantis achieved. The slope is seen on the navisphere as 62 or 63°. The time on the top right shows the second image was taken 3 seconds after the first, and the speed gauge shows increased speed, showing that the rover could accelerate while going upwards a 62° slope. That's its utter limit; accurate use of SAS is necessary to get grip. And those 3.8 m/s are pretty much its top speed in this condition. Battery will lasts maybe two minutes.

    It's also quite complicated to rest and recharge the battery; even with brakes, the rover tend to slip.

    I keep complaining that you can't appreciate perspective, so I reloaded back and took some better pictures from the eastern ledge, after climbing the worst part of the west wall (yeah, it's really a confusing name, but it does sound cool)



    The rover is the white dot in the center of the image

    The 8-km hole is less than 100 km before the halfway point of the circumnavigation. Biome is still the Boreth mountains, this range encompasses half of the planet while the other two are shorter.

  2. Part 4: Mountaineering galore, part 2

    Yes, more traveling across the mountain range. Leaping Mantis changes biome, but the mountains are the same. I miss the variety of Slate.


    yeah, though I walk in the valley of really bumpy terrain, I will fear no wheel breakage: for the mantis claws are with me


    Actually, even the mantis claws can't always protect my wheels. I still need to reload quite often, even though after the first hundred kilometers or so I learned to drive better. To counteract that, I brough as many repair kits as I could (do notice the additional storage space for repair kits on the wheels trusses). To avoid depleting them too fast, I only repair a wheel if it's been more than 5 km since the last time I saved - else I reload the game. I plant a flag every 20 km, and I always save there; plus, I generally save a couple of times between flags. So, there's really a short time interval where breaking a wheel would result in using a repair kit. Even then, at the time of this writing I miss 150 km and I'm down to the last kit.




    Here I'm slamming against a wall at 46 m/s. I don't know what happened next. That's a borderline speed, in that at that speed sometimes Leaping Mantis hits the ground and survives (yeah, it's really sturdy), but it's far from guaranteed.


    This lump of terrain doesn't look like much, but it's the tallest elevation on Wal. I called it mount Lump


    The sky is also very pretty, at least from the part of Wal where Urlum is visible

    Speaking of sky and visibility, I'm using pretty strong light amplification here. Unfortunatly, the color of Wal is really bad for contrast, and it's very hard to understad the terrain in natural light. Even with artificial light enhancement, during the night visibility is poor. At two distinct points during the trip I stopped the rover and waited for the new day.


    A section where a crater chipped away a major chunk of mountan, resulting in a pass with much lower elevation. The mountain profile forms almost a perfect arc, only broken by the reverse uvula - so called because the profile of this mountain section looks like a troath with an uvula, only flipped vertically.

    Wal is a place of extreme elevations. In a few kilometers the altitude dropped from 18 km to 13, up to 15 again at the reverse uvula, down to 11 in the lowest point of the pass, and up again to 16. 11 km altitude has been a record low in the last 500 km, though it's going to get lower at the biome change.


    The biome change, aerial view

    This is the place where the Gault mountains end and the Boreth mountains begin. The Boreth mountains are on average one km lower than the Gault - I don't remember ever crossing 20 km again - but aside from that they are identical. This goal marks roughly one quarter of the voyage; Leaping Mantis landed at 150° W, and it's now at 55° W. Leaping Mantis has run around 700 km; it probably becomes a higher number if we account for all the ups and downs.



    I went down, really far. You may notice something unique here: rocks! Yeah, they are just normal rocks, authomatically generated by terrain scatter, what's so special with them? Well, do you see any in the previous images? Nope! They stop appearing somewhere between 10 and 11 km altitude. You can say that Wal mountains are so high, not even rocks grow on them!


    I should have stayed over the crest, but I took a slight detour to collect a sample from another biome



    A few km later, I'm again high enough that rocks disappeared


    Climbing a 55° slope. Leaping Mantis has a vey hard time, but it's actually making it


    I tried to turn the lights blue to see if it looked better. I eventually swapped them back to white


    This last place I named mount Stegosaurus, because from the profile it looks like a stegosaurus back - something that cannot be fully appreciated from this image. But it does give a stunning view of the plains 15 km below.

    That's close to one third across the planet. Time for another stop.

  3. 2 hours ago, intelliCom said:

    I'm referring to really damn advanced though. Fission fragments, fusion, NTR, ones that don't exist in reality. All the standard rocket engines have seemingly normal values for burn duration.

    Literally all of the advanced engines carry the same burn durations, as mentioned before. This doesn't seem right to me, and I wanted to know if the numbers are provable or just placeholders.

    so you are talking about far future engines. as far as i'm aware, kerbalism is not made with those in mind. as i said, there is a formula, and as far as I am aware (note, I am not in the dev team or anything, just a long time user) the equation is used for engines that the mod doesn't recognize. kerbalism is not even supposed to be strictly compatible with the far future stuff (while it is supposed to be compatible with near future)

  4. 3 hours ago, intelliCom said:

    Just started using Kerbalism for the first time; I've noticed that a lot of the higher-tier engines (mainly the Near Future and Far Future stuff from Nertea) have the exact same burn durations: 10 minutes standard, 40 minutes high quality. Why is this?

    Apparently the author is no longer developing it, which is a shame. Perhaps it would be worth someone figuring out what the burn durations should be?

    i think there is a formula for allowed duration and ignitions that takes into account thrust, Isp(vacuum) and Isp(sea level). basically, the more powerful an engine is, the more it is atmospheric-optimized, the less burn time and ignitions it has. until it hits a minimum, and can't go lower

  5. Part 3: mountaineering galore, part 1

    Leaping Mantis travels across the mountain range.



    Leaping Mantis landed at the base of the mountans. Now it has to climb some 10 km to reach the summit.



    Leaping Mantis path is crossed by those wave-shaped formations


    Up to a 50 degrees slope, Leaping Mantis keeps pushing forward



    Finally, the summit

    Actually, now that I'm on top, it looks even a bit flatter than the rest of the planet. Not that it is a high bar to clear.

    From this, Leaping Mantis starts its real voyage.

    Unfortunately, as I said, Wal is a lot less fun that Slate. Slate had an interesting geography; it had valleys and canyons, and it had different biomes with different characteristics. Here on Wal, there is no such variety. The mountains are not dug by ancient water, they are just a jumbled mess of chaotic terrain. The big equatorial mountain range is split into three different biomes, but they all look similar.

    So, instead of providing a narrative like I did in the previous circumnavigation, I'll just post a photo gallery. Mostly without much comments, unless there is something specific to comment on.



    Here I was desperately trying to save a rover capsized at high speed by landing on the rooftop wheels and going backwards. As I started in march, I don't remember if I was successful or not


    Here I found a bit of flattish terrain, and I took the chance to run faster for a while


    I named that place the football field plateau


    Here the mountain range is interrupted by a crater, only a thin crest remains



    Navigating the aforementioned crest


    Because driving on Wal was a lot more boring than on Slate - and still very dangerous, despite all of Leaping Mantis safety measures - this mission went slowly. Some days I'd drive 100 km, some days I'd drive 20, and sometimes I would go full weeks without even touching it. As a result, I started in march and today 20 october I still miss a couple hundred kilometers.



    The most difficult features to cross are ravines to be cut diagonally. Here the smallest mistake may lead to the rover jumping laterally and falling for hundreds of meters before rejoining the ground the hard way



    This is why, while a low baricenter helps stability, you still want the main body of the rover to be high above the ground



    And that's it for part 1. In retrospect, I should have snapped pictures with more references on progress made, because I'm not sure how much road I've done to that point.

    Anyway, I'll keep updating later.

  6. Part 2: launch and cruise

    Leaping Mantis was delivered on Wal by a relatively minimalistic sky crane.


    Leaping Mantis ready on the launchpad


    Leaping Mantis has a large area, presenting exceptional aerodinamic challenges.

    For Tamarromobile, I used a huge aerodinamic fairing, which was more massive than the rover itself. In this case, it would have been way too heavy to justify its mass. So I launched the rover unprotected, trusting in extra thrust and deltaV to compensate. I put the rover at the bottom of the stack so it won't cause aerodinamic instability.


    Jettisoning the boosters


    Once the atmosphere is cleared, the rhinos are used


    In space, the nose cones are removed for mass reduction

    Urlum is far, I'll use a Jool gravity assist to get there.


    Leaping Mantis plans a Jool gravity assist


    Jettisoning the last stage of the launcher

    Now that the launcher is removed, the cruise stage is a couple of large tanks with nuclear engines. There are a couple of relay satellites embedded in the stack. For return, I will use a small ion-powered pod like I did for Tamarromobile.

    I decided to simplify a bit the architecture from the previous mission by not having a dedicated vehicle to leave Wal; instead, the sky crane has some extra fuel and will double as Wal ascent vehicle.

    I am still using a version with kerbalism installed; I deactivated some of the harshest realities of kerbalism, but I still have to provide food; I loaded enough for 30 years, which makes quite a large pile of snacks.


    The cruise stage leaves on nuclear engines


    The cheapest path to Urlum


    The fast path to Urlum

    From the Jool flyby, I could find - with the help of a couple correction maneuvers - a path with a very clean injection at Urlum. However, it would leave me only three years worth of food. Since I have some extra fuel, I opted for a faster trajectory, spending a bit more on deltaV to shorten the trip by several years.


    Planned arrival at Urlum

    For arrival at Urlum, I use direct intercept at Wal; this way I can use the large moon's Oberth effect and orbital speed to reduce the injection cost, resulting in a cheap capture despite a less than ideal trajectory.


    Arrival at Urlum with 10 years left of food. Water estimate is wrong because it's not accounting for water recycler


    Capture burn. And first glimpse of Wal


    Releasing the two relays in high orbit


    Jettisoning some empty tanks


    The second stage of the cruise stage takes care of circularizing


    Sky crane separation



    Landing is potentially difficult, because of the terrain. I'm trying to aim for a large flattish area next to the mountain range, as a place that's less likely to have 45 degrees slopes.


    After a bit of trial and error, I managed to find a bit of flat ground to land safely

    And now the real challenge begins.

  7. After I had a lot of fun circumnavigating Slate's rugged terrain on an oversized rover, I decided to ramp it up by circumnavigating an even more rugged terrain: Wal.

    This moon of Urlum is surrounded on the equator by a massive mountain range; the plan is to make a full Elcano traveling over mountaintops, hence the title. Full title actually would be The starry heavens above me, a sturdy rover enclosing me 2: Look at me, I'm Reinold Messner!, but it was too long to fit.

    The circumnavigation was indeed very challenging, but it was also a lot less fun that I was hoping, due to Wal ugly and unvaried terrain.

    But let's go with order. Half my resons to pick up challenges is to design vehicles to tackle them and check if they are really up to it, so I must start with the rover.

    Part 1: designing Leaping Mantis


    To travel mountains in moderate gravity, I need something with a lot of traction and a lot of survivability.

    For traction, I have 16 ruggedized wheels; with 10.8 tons of rover mass and 0.37 g, this setup allows climbing up to 40° easily, and up to 55° with difficulty, before I have to resort to switchbacking. Which I still had to do a couple of times, because Wal is hard.

    For protection, I have the active system in the form of three reaction wheels; this rover can turn midair really fast, which is important when you are in a place full of bumps, with a gravity strong enough to pull you down fast, but not strong enough to keep you glued to the ground. Leaping Mantis almost always lands on its wheels. For those times when it doesn't land on its wheels, it has a minimalistic, but effective, roll cage made by the plane wheels on top and the landing struts behind. The main limitation is that if I capsize the rover while going downhill, it may survive the first hit, but it will keep falling and accelerating until eventually the roll cage is overcome.




    The reaction wheels are not strong enough to turn around the rover if it lands capsized, so I included a robotic arm to help with the task. I wonder why I didn't just add a couple more reaction wheels.

    The most important protection system, though, is the couple of plane wheels in front - which I call the mantis claws, giving Leaping Mantis its name. When I was circumanvigating Slate, the main reason for rover damage was taking bumps in the ground at high speed. If the terrain makes an angle in front of the rover, the front wheels are practically hitting a wall. To protect in this scenario, which is extremely common when climbing mountains, I devised the mantis claws. The plane wheels are in front of the others, they are a lot more resistant, and they cushion the impact.


    I started driving straight on against rock walls just for the novelty of being able to


    Finally, I always want my rovers to have a good view from the driving place, and this one is no exception.

    However, in this case it turned out not very useful. This kind of visual was very effective on Slate to detect hard bumps in the terrain. Here it was pointless, because the mantis claws protect effectively from those. Furthermore, Wal color palette has a lot less contrast, making it a lot harder to see where you are going. What I found really useful instead was seeing if there is a ravine over the next crest or not; and for this I need the outside perspective, to watch the rover from a elevated perspective and see more of the terrain. So, first person driving perspective wasn't used much.

  8. 23 minutes ago, magnemoe said:

    Now the question is why an long range SSTO
    I launch them into LKO dock the a space station or something designed to operate in deep space. 
    This is an Laythe base with its spaceplane on top. An tanker above that just topped off the tanks. 
    Its an 3 stage rocket, chemical, an LV-N second stage cross feed to the tug with side mounted LV-N and the base who has enough fuel and oxidizer to land on Pol. 
    Jool trip will be a bit more than an year. 
    First stage will drop during the Jool injection burn, second at Tylo braking. Needed an intercept getting into Pol orbit but had another tug fueled so no issues. 
    Also you might want kerbals to enjoy spin gravity during their trip. 

    yes, it is more efficient to use the ssto to bring to orbit a ship optimized for vacuum, but some people use ssto to everywhere for the challenge.

  9. 5 hours ago, miklkit said:

    Uh ohh, Dres is hard to get to from Jool?  I had hopes of using it as a refueling base. 

    getting from jool to dres and viceversa is not too expensive, actually; from the outer moons of Jool (Bop and Pol) you can reach Dres with 1500 m/s. The problem is, why would you? Bop and Pol are both excellent refueling places, with their low gravity. If you're around Jool, you want to refuel there.

    From Dres to Jool is cheaper, as little as 500 m/s, because you can use gravity assists to get captured. So if you want to use Dres as a refueling base, you need to spend 2 km/s just to get to/from there. And transfer windows between those two planets aren't exactly common, it may take a decade for a round trip.

    If you're coming from the other direction, at Duna wanting to reach Jool, going directly is cheaper than going to dres. A duna-dres transfer always costs over 2 km/s, because inclination results in a large intercept speed at Dres. Conversely, from Duna you can reach Jool with 1 km/s, once more using gravity assists to get captured.

    All this makes dres useless as a refueling base. If you want to go to jool from the inner system, it is cheaper to skip dres and go to jool directly. If you are already around Jool, it is more convenient to refuel around its outer moons. if you aim for eeloo, once more jool is a more convenient stop to refuel. And if you are around Jool/eeloo and want to return to the inner system, it is cheaper to go directly to Duna.


    it's an unlucky position. I'm using rss, and ceres/vesta suffer from the same problems; even though they would in theory be viable spots, in practice it is better to go elsewhere.

  10. Part 6: EVEntually you find a way when you need it MOHOst

    The missions for Eve and Moho reach their intended destinations. There were a lot of unplanned difficulties, especially on Eve, but all worked out in the end.

    In other news, the asteroid is caught without problems. The Jool mission is in jeopardy and it got lightened of its arrays like the Eeloo mission.


    Eve landings rarely go as planned


    First mission about to arrive is the asteroid catcher.


    Asteroid catcher about to grab its target

    It's got plenty of fuel and the asteroid is relatively slow-moving. Way overkill.

    The Jool mission worries me, it's costing more than planned and I risk not having enough xenon to return. Since a lot of mass was the four relays and I already sent a new one for Eeloo, I figured I could do the same here. For Jool I want at least two of them, and for simplicity I want to launch them together. Also for simplicity I don't want to have to design another launch vehicle, so I came up with joining two copies of the Eeloo backup relay.


    The Jool relays ready for launch


    First stage separation

    And they worked pretty well. Some aerodinamic problems with that big antenna, but nothing that cannot be overcome with deltaV.


    Scanner-Relays route to Jool

    This time I have a bit less time constrants because I don't need to return those relays, and the planetary alignment is better. The relays can be sent to Jool cheaply enough. Intercept speed is around 5 km/s.

    Now that I'm safe in having some backup scanners, I can remove some dead mass from the Jool mission.


    Away the scanners


    Now that there are no more docking ports, an EVA engineer also removes empty tanks


    the new Jool mission

    I got rid of 7.5 tons. I still don't feel safe, but it's an improvement.

    A few days forward, the asteroid catcher finds the asteroid.


    It's smaller than expected, but harder to grab than anticipated


    Capturing the asteroid

    It turned out, the asteroid catcher has enough fuel to move the asteroid in Kerbin orbit without even needing to mine more. With enough fuel left to move it to a safer orbit where it won't risk hitting Mun. With enough fuel left to go anywhere around Kerbin.

    Well, that's one item of the list I can cross.


    After course corrections, the Eeloo relay is set for an Eeloo intercept. Fuel is plentyful, no problems foreseen


    The Eve lander arrives to Eve


    And finds a trajectory for Gilly


    Where it drops the scanner-relay

    Remember, the plan is to refuel on Gilly, then use fuel to rocket brake. This way I don't have to invent a thermal protection system for the Eve landing.


    Orbiting Eve

    I completely missed taking screenshots of the time spent on Gilly.

    Then again, I was orbiting Gilly, with a bit of fuel left, and a ship that already managed to replenish its fuel tank in 3 days. You can trust that I could land and resupply without showing pictures.

    Now, before I land on Eve, I need to detach the return pod. That was stored in two pieces.


    The return pod: some assembly required

    Alas, the back part - which has the engine - doesn't have signal to maneuver, so I have to reload and bring in the scanner-relay.

    I took some pics of the trajectory involved, but really, those things have 5 km/s, and it only needed to go from Gilly to high Eve polar orbit. I think I can skip the passages.

    One thing I won't skip, instead, is mentioning that I almost failed to get a scan because scanning Eve took a lot more electricity than other places. Maybe it's related to the planetary surface? Anyway, the probe didn't have enough battery.


    Eve scanner out of battery

    It's been a long, long time since last I scanned a planet. But reading the wiki, I discovered that I can set antennas to transmit the science in small packages. So it took 10 minutes, but it could download the data. It's weird that this setting is not the default; what possible advantage is there to losing a science transmission rather than wait a few minutes to download it?

    Anyway, I could scan Eve, the mission is safe. Wait, I read the conditions of the challenge again and they mention nothing about scanning. What the hell? I'm sure it was mentioned, and performing science too. No idea. Anyway, now all my missions have scanners, may as well use them.


    Return pod assembled successfully


    Rocket braking to land


    Burning up in the atmosphere

    Ouch! Not enough fuel. Did I make a faulty vehicle? Can this mission be salvaged at all?

    Reload back and find out.


    This time I actually took a pic of Gilly

    Above pic is to show that the ore tank is full. The previous time I just forgot, assuming I'd have plenty of fuel; I also skipped loading a few tons. Totally neglectful.

    But the bunch of extra fuel is not enough for a safe landing. No, I need to aerobrake. Can this ship aerobrake practically? Whether I will continue this challenge hinges on this question. I have exposed solar panels; if I have to keep a too shallow periapsis and brake for less than 1 m/s at every passage, it would become way too boring - and time consuming - to do and I will just give up. First I'll spend a few hundred m/s to bring orbital time below half a day, because this is still a time sensitive mission. Then we'll see.


    At periapsis, 4 m/s lost. Nothing is exploding


    Out of the atmosphere, 7 m/s gained

    Seven m/s. Not ideal, but it's something. And after a few passages, with lower apoapsis the lander spent more time in the atmosphere and increased braking.

    Now I just have to do this... a few dozen times... On the plus side, none of the other missions will require my attention for the next 60 days or so, I don't have to worry about missing maneuvers.

    Remember to keep the ship constantly rotating, else the solar panels will burn up. I also have to repeat the maneuvers with the relay, with its slow ion engine. Sigh. Sometimes the stuff I do for this game makes me wonder if I'm secretly some kind of masochist.


    8 days and many, many atmospheric dips later

    I should be ready to land. Let's try.

    Even though I had enough fuel to slow down to 1500 m/s, Eve's gravity is really strong, and it accelerates the lander again. No, I couldn't follow a more shallow trajectory like in a suicide burn; I had to keep out of the atmosphere.




    The rocket survived, damage assessment

    Turns out I lost only three pices: one solar panel (out of 6) and two landing legs (out of 12). I don't want to keep aerobraking (not to mention assembly the escape pod and everything related to it), let's try and see if the lander still works.


    At least it's got enough parachutes to land without rockets. Touchdown was successful


    Ejecting those lateral tanks with parachutes


    The previous model fell over the rocket, but two sepratrons instead of one did the trick


    Tommaso went out safely from the dedicated "elevator". He didn't even need the ladder

    Now a few more days of ISRU, and we'll be back to orbit.


    Liftoff. The landing legs have a bit of fuel, may as well use it before jettisoning


    The second stage up high in the atmosphere


    The last stage, in space

    Ok, this trajectory must have been horribly inefficient. It's a problem with Eve ascents I never managed to fix; first you want to go straight up to avoid the atmosphere, as fast as possible to reduce gravity drag. Then you would like to perform a gravity turn, but you're already going very fast and the atmosphere is still very dense and you can't steer, you have to keep going straight up. Well, the lander had more than enough deltaV to compensate.


    Moving to the return pod, carrying science

    Orbital mechanics are unfavorable to return to Kerbin now, and I have a chemical engine, not some ion engine with 10 km/s (probably I dreaded needing a dozen apoapsis raising maneuvers to escape Eve's gravity). I must be somewhat conservative, Tommaso will wait in orbit for a while. Meanwhile, the Moho mission is also arriving.


    At Moho


    Separation with the scanner-relay and the cruise stage once in orbit


    Detaching the lander




    No problems


    Back to orbit

    The lander had a good 300 m/s more than needed, all went well.


    Trajectory to return to Kerbin

    For this mission I overestimated how much xenon I'd need, so I now have 17 km/s. The only mild complication is that I would like to start with a burn on the shadowed face of Moho, but the solar panels disagree with that. Still, I have such a stupid amount of xenon, returning is trivial. I'm not even trying to optimize the trajectory.

    Now back to Eve; the purple planet reduced distance with Kerbin, and even though the ideal transfer window entails an arrival in year 3 (i.e. too late) now it's good enough.


    A 3800 m/s to return to Kerbin. The return pod has 5200 m/s, it will be safe


    But it runs out of fuel before completing the maneuver

    Yep. Having the thermal shield decoupling in the same stage messed up with the deltaV assessment. I really only have 3300 m/s. I have to look for another trajectory.


    Here it is, to Kerbin with 2700 m/s

    In this trajectory I burn retrigrade at apoapsis to time the arrival on Kerbin at the next apoapsis. It's not an ideal flight plan, but it will bring Tommaso home before the end of year 2.


    Some EVA engineering on the return pod

    I should not need more deltaV, but just in case a bit of EVA construction allowed jettisoning the spent tank. I can't get rid of the docking port because it's the root part, I put the engine back on it.

  11. 8 hours ago, miklkit said:

    Ah, so there are scannable things on Dres.  That makes the building of a rover carrier with that range necessary.  I thought I would already be seeing contracts for Dres, so thought there might not be any after the chatter about how boring Dres is.  I am finding it quite challenging in fact.


    Reaching dres is fairly challenging, and expensive. Because it is so expensive to go to dres from anywhere and back, the place is virtually useless as refueling base. 

    Once landed, it's basically mun without craters - and a more rugged terrain. It is the hardest place to drive a rover in the stock system, according to several rover junkies, because the irregular terrain breaks wheels easily. 

    I think those are the main reasons dres is disliked; you can't use it for much, and after all the trouble of getting there it's very anticlimatic

  12. 1 hour ago, miklkit said:

    I recently landed on Dres and have been setting up a science base.  While wandering around I came across this oddity.  Since landing I have gotten no contracts for Dress, but have already started getting some for Jool.  Anyway, a Kerbal can not interact with this thing and I'm wondering if it needs to be scanned or if there are no contracts for Dres.  I don't want to go to the effort of sending a rover with a scanner arm if it is not necessary.


    what do you mean by "necessary"?

    if you're arrived to dres, by now you should have unlocked the full tech tree, and have virtually unlimited money, so nothing is really necessary.

    if you are just asking "can I scan that stuff? is there scannable stuff on dres" then the answer is yes. I have never seen this specific rock formation, but i haven't been to dres in several updates; you may also have graphic mods. either way, dres has two scannable objects, so a rover arm will be useful.

    I don't know why you didn't include one already; i see your rover has six of the biggest wheels, totaling 9 tons alone. plus the mk3 cockpit and a bunch of crew pods, that thing must be at least 30 tons. compared to that, the 300 kg of a rover arm make no significant difference, you may as well add one.

  13. 1 hour ago, AlSlea said:

    After a bit more flying in my new science plane, I've picked up some more science. Not sure I can hit the target at this point - how much else is there to do, really? But we shall see.


    which target are you talking about? i didn't notice any.

    if your purpose is to complete the caveman challenge - that is, just grabbing some more science - you can easily make a couple more mun landings in different biomes and get easy science.

    if your purpose is to explore all the planets, you can make it at least as far as duna with the money you have. though for me going interplanetary in caveman was quite the challenge and it required learning on the fly

  14. 23 hours ago, Quadkiller said:

    Thanks! I think that it may or may not be better to combine the burn depending on the scenario. On the one hand, you want to save fuel by combining burns with the Pythagorean theorem. But you also want to change inclination near apoapsis since its cheaper. In the ideal case, your relative ascending node is already near apoapsis so you get the best of both worlds. But I'd image if your ascending node is far from apoapsis, you might actually be better off partially fixing your inclination at apoapsis first.

    yes indeed. in your case, you were already pretty high in the node, and the normal component was a lot smaller than the retrograde component, so it was a clear case of combining being better. there are other cases where splitting is better, as you said.

  15. 12 hours ago, Quadkiller said:

    So long story short, I ended up in this really wacky elliptical orbit and I'm trying to rendezvous with my space station in a polar orbit around the Mun. Here's some screenshots: https://imgur.com/a/UP4n12P.

    I'm creating a maneuver at the relative ascending node with the goal of lowering my orbit so that the burn location becomes the apoapsis, the periapsis becomes 30km (where the polar station is), and the relative inclination is 0. Naturally this involves burning in a combination of all three axes. It's pretty easy to get a very rough burn set up by eye, but refining it is a real pain. The main issue is that I can only edit the burn in the coordinate system of my current orbit, which is completely misaligned from the coordinate system of my target orbit.

    For example, to adjust the periapsis the best I can do is use anti-normal since its the closest to the prograde direction of the target orbit. However, this is far from ideal since it also adds velocity in the radial out direction (which messes up my apoapsis location) and the anti-normal direction (which messes up my relative inclination) in the target orbit coordinate system. What I end up doing is going in circles fixing the relative inclination, periapsis altitude, and apoapsis altitude one after another until I slowly converge to the optimal burn.

    I've run into this exact issue several times now, and its always a bit annoying. From what I can tell, the optimal solution would be a toggle that allows you to switch to editing the burn in the target coordinate system. This would mean that the directional indicators would rotate dynamically as you add velocity in the various directions. Has anyone else run into this? Any mods/general tips for making the process easier?

    your maneuver looks excellent. if you still end up with a degree or two of inclination, you can fix it with very little fuel.

    no, I don't know any way to change the reference system of your burn. but you handled it really well as it is, and managing like that is a lot faster than trying to find a mod to do slightly more easily something you can already do pretty well on your own.

    P.S. splitting the manuever is not going to make it cheaper, in fact by combining the manuevers you save fuel thanks to pitagora's theorem. you get the normal and radial components almost for free.

  16. Part 11: Closest thing we've got to a comet

    I wanted to include a comet in the grand tour. Since the game is not spawning any comet (new bug #33), I went for the closest approximation available: an asteroid in a highly inclined, elliptical orbit.

    The target is very challenging, but the Cylinder/Fat Man combo is up to the task.


    If the game is not spawning comets, I'll at least pick a large asteroid

    11.1) Preliminary work


    After my previous OPM grand tour, I decided to include an asteroid and a comet as destinations in every grand tour. I can easily skip asteroids, because getting a near-Earth one is very easy. Comets are challenging targets, and I definitely want to get one.

    Throughout this mission, I kept track of unidentified objects, thanks to the infrared telescope on Wings B. But the game never spawned a comet, likely due to a mod malfunction. However, it did spawn several large asteroids in comet-like orbits, and lacking a real comet I'm going to one of those.

    With an inclination of 45 degrees over Earth, asteroid NZK-022 is impossible to reach without a gravity assist from Jupiter.


    Asteroid NZK-022, its orbit shown compared to Jupiter


    From this perspective, the inclination can be better appreciated

    Getting such a high inclination requires arriving to Jupiter with high speed. A simple Hohmann transfer won't do. So I'll have to spend at least 4 km/s for the Jupiter transfer. Then, in the most favorable scenario, I can match inclination and periapsis; but a rendez-vous with the asteroid will still require lowering apoapsis and a radial change, for at least 3 km/s. And then getting back to a Jupiter encounter will require just as much. And from Jupiter I get back to Saturn, and I can use Titan to aerobrake some, but I still need to have some fuel left. And so it looks like the 11 km/s of Cylinder cannot suffice, even under the most favorable conditions.

    However, I can extend my deltaV by using Fat Man, just like I did with Mercury. I can make a high speed flyby of the asteroid with Cylinder, and have Fat Man pay the 3 km/s to slow down to the asteroid, and other 3 km/s to return to Cylinder - which is still in a Jupiter intercept trajectory - afterwards.

    This is the plan. I lift off from Iapetus and start simulating trajectories.


    Leaving Iapetus, once more


    Not without some hiccups. It is not rare that A'Twin undergoes a spontaneous RUD, but this time the debris cloud was quite spectacular

    I had a half dozen tracked asteroid in interesting orbits. I picked up NZK-022 for a very practical reason: by starting immediately, I could get an intercept to Jupiter very close to its ascending node. For the other asteroids, I'd have to wait a more favorable alignment, and I didn't want to wait.

    Time is going to be another important factor for this mission. Cylinder has supplies for 60 years. With the orbital times involved, I may need all of them. For this reason, I wait until a few days before the Iapetus ejection to separate the two A'Twin subunits.


    Obligatory rearranging of the various shuttles while splitting the ship


    Trypophobia module, ready to land back on Iapetus

    I initially wanted to use some fuel from Trypophobia to further boost Cylinder's orbit, but I realized the mining module can barely land on its own already. It doesn't have much fuel to push a fully loaded, very heavy Cylinder. Indeed, after a few calculations I even had to transfer a few tons of fuel back from Cylinder. Trypophobia barely has enough fuel to land.

    I picked the crew by leaving behind kerbals that were most active during the Jupiter campaign. Except poor Jeb, who should have participated, but was left behind for a shuffling mistake.


    Cylinder module, ready to chase a comet

    Cylinder is full to the brim with supplies. I loaded all the water and fuel I could get. I even carried Nitrogenie in a Bottle in this mission, solely because it has a 3 tons water tank. I figured a couple extra years worth of water were more valuable than a couple dozen m/s I'm losing for the extra mass. Of course, no oxidizer because no lander is involved. The bit of oxidizer left in the tanks is caused by bug #31.


    Landing Trypophobia back to Iapetus

    In its status screenshot, if one took the time to run the deltaV calculations (the gauge on the left is inaccurate, as it often is for large complex ships) it looked like Trypophobia didn't have enough fuel to land. But that's because it was still burdened with extra supplied it ended up not needing. Here I dumped all the water and the uranium, down to the last ton.


    Landed, by the thinnest margin

    The poor Trypophobia barely had a couple seconds of ignition left when it touched the ground.

    11.2) Outbound trip


    It takes 5 km/s to reach Jupiter with the current alignment - already a fair bit more than I planned. It's not in a good position to reach from Saturn, it requires dipping perihelion all the way to Venus orbit. But at least it will give me enough excess speed over Jupiter to exit in the direction I want.


    Option 1 for leaving Saturn: direct ejection from Iapetus

    I considered doing some tricks to get a Titan gravity assist. According to the picture below, it could have saved some 400 m/s roughly.


    Option 2 for leaving Saturn: Titan gravity assist

    In this scenario, an 840 m/s burn at Iapetus would lower Saturn periapsis to the edge of the death zone, where a 175 m/s burn would syncronize the orbit for a future Titan flyby, By making a burn at Titan periapsis, I can save some fuel from gravity assist and extra Oberth effect.

    I didn't take that path. Not sure why, it's been almost one month ago. Possibly because it would take 90 days t get to Titan, and that may affect getting to Jupiter at the right time for the ascending node of the "comet". Or maybe because it involved a long burn at periapsis, which would surely have suffered from cosine losses.

    To avoid cosine losses, I instead opted for a small burn to exit Iapetus, followed by a big burn in Saturn orbit. It was the most precise option.


    How I actually left Saturn: big burn in Saturn orbit, no worry about cosine effects

    Still wasn't that easy. For such a long burn, I had to stop and service the engines twice. And then I had to do it over because I missed slightly the proper timing to Jupiter, missing the ascending node.


    Full trajectory to the "comet"

    As the picture shows, I'm leaving Saturn with a very low perihelion, reaching inside Venus orbit, to catch up with Jupiter. In this picture the big burn to leave Saturn is split into two smaller burns, because I was still exploring ways to try and make it cheaper. Anyway, after one more correction maneuver in 4 years, Cylinder will meet Jupiter in six and a half year. It will pass slightly outside of the orbit of Callisto, the outer moon, so no radiation problems there.

    This gravity assist will change Cylinder's inclination, flinging it on the purple orbit. That orbit has a lower periapsis than the "comet", because if I matched periapsis exactly I wouldn't get a rendez-vous. Orbital timings aren't conveniently aligned, and I had to exit on a more elliptical orbit to compensate. However, meeting the "comet" in those conditions - crossing its orbit instead of touching it Hohman style - would have resulted in too much intercept speed, roughly 8 km/s (see the next image). I can tolerate 4 km/s intercept speed, maybe 5, because Fat Man must pay that twice. So, another maneuver is planned close to aphelion (not at exact aphelion, I can move it around a bit to refine the orbital time) to raise perihelion at the proper time to touch the "comet". It results in an intercept speed of 3 km/s, and an encounter after 20 years, for a total cost of 6 km/s.

    This trajectory leaves 40 years and 4.5 km/s to find a way back to Saturn.


    What happens if I try to save fuel by skipping the periapsis raising: 8 km/s intercept speed, too much. And if I exit from Jupiter with higher perihelion, I miss the "comet" by weeks

    This time, luck is not with me; I soon start breaking up stuff, and a lot of those are critical malfunctions. It's very hard to keep a regular repair schedule on a multi-decade mission, on two different ships with very long loading time.


    Malfunction: lost the reaction wheel on Nitrogenie in a Bottle

    That's annoying because it cannot be replaced; still, I did include lots of reaction wheels in the back specifically to have extra torque. I really hope I won't have to actually try a Titan ascent with two asymmetric engines, though.


    Malfunction: lost a life support unit on Dolphin 2

    Now Dolphin 2, like its sister ship Dolphin 1, is down to five working life support units. Still no concern.


    Malfunction: another big fission reactor

    Ouch! This one is starting to hurt. Up until this point, all the ore I was mining on Iapetus (which has 9% ore concentration) was processed to extract CO2. Now Trypophobia won't have enough power to process the ore faster than it is mined, so ISRU will be a bit slower.

    Still, considering that I'm entering the part of the mission where I face multi-decades travel times, spending one or two years more on Iapetus is not a big deal. Fast mining was a lot more important while I was in the inner system, and I had transfer windows to take.


    Jupiter is reached without further accidents

    I already lost three parts in six years, one of them a precious reactor. Did you want even more accidents?

    There are still a dozen more years to reach the "comet", so there is time for more accidents.


    Malfunction: an antenna on Wings A

    Ok, I still have a handful of replacements for those. But I'm waiting to install one because as long as I keep it in storage, it can't get broken.


    Malfunction: life support failed on Nitrogenie in a Bottle

    While I would have preferred to keep it functional, Nitrogenie is not supposed to carry a crew except on its very first landing, which it already performed. So, no harm done.

    By now I'm starting to get close to the "comet".


    Two years from the target, status

    So far Cylinder has traveled 17 years, and it used up 25.4 tons of water. An average of 1.5 tons per year, almost exactly. So there's still water for 45 years. The ship still got 5.5 km/s of deltaV, though it will have to spend some fuel to move Fat Man shortly.

    You may notice intercept speed is 400 m/s higher than it was supposed to be in the trajectory shown earlier. Planned trajectories are not followed exactly; there are small approximations made when burning, and then course corrections, and then I have to plan the trajectory again and it won't be exactly the same. In this case it resulted in a pretty large difference, luckily a few more tons of fuel used up by Fat Man mean absolutely nothing to Cylinder's greater fuel budget.


    There is still time for one more malfunction: a life support system on one of Cylinder's own crew pods

    Six broken parts in 18 years worth of traveling. But, due to bug #15, only some parts are getting degraded at a fast rate. And with this piece, all of them are either critically broken, or reversibly broken and I'm not going to fix them so they can't get broken again. So the bleeding should slow down now.

    And no, that last part is not an issue either. Not only Cylinder has a bunch of redundant life support, it's supposed to work entirely on the life supports of its Dolphin pods.

    11.3) Encounter


    We're finally arrived at the "comet". Half an hour before the close approach, I detach Fat Man and start slowing down.


    Shortly before the encounter


    Fat Man leaves, burns retrograde to the comet

    The burn takes some time because of the low thrust, but it presents no problems.

    The "comet" is big, an F class object. It was somewhat funny to see it appear suddenly as it entered physical range and occupy a large part of the sky.


    Close to the "comet"


    Rudatte takes a sample. And sinks into the "comet", the ground glitching. Nah, that doesn't even deserve a mention in the bug list


    Rudatte returns to Fat Man... but he can't hold the sample!

    Aww, crap. Fat Man doesn't have a storage space for samples. It's supposed to carry around landers, and those landers have sample storage aplenty, so the problem never came up before.

    No, no way I came this far, went through so much hardship to get this "comet" and I'll just give up on keeping the sample. Though the mission doesn't require it, I am going to keep the sample if I have to return to Cylinder with Rudatte hanging from the ladder.


    Yep, I have to. Rudatte hanging from the ladder with her precious sample

    Return to Cylinder, of course, is performed by setting it as target - it's now leaving at 3300 m/s - and burning enough to make up for that speed difference. Then burn some more to get closer.

    I still got more problems, though, or this part wouldn't deserve a subchapter of its own. Because after using the engines so much, they need servicing. Here I discover another problem: out of eva propellant!


    Toboono (engineer) is out of EVA propellant

    Monopropellant is used for EVA, and I never refilled the storage on Fat Man. There were 3 units left, and Rudatte took them when it went out. The first kerbal going out always takes as much monoprop as it can get.

    Luckily, having also a pilot on board left me with a solution. First I also sent out Monbrio. He took the sample from Rudatte, because EVA kerbals can swap samples with each other. Then I sent Rudatte inside, thus restocking Fat Man monoprop supplies. Then I sent Tobono inside, and outside again, and this time he had monopropellant and he could go fix the engines.


    The trip towards Cylinder

    Meanwhile, even though the stop at the "comet" was short, Cylinder was moving away at 3 km/s, and it's at 7000 km by now. After equalizing speed I spent another 500 m/s to return fast, but it's still going to take a few hours. An EVA kerbal only has air for 2 hours, but this limitation can easily be overcome by sending out a new kerbal, with fresh air supplies, to take the sample while the other kerbal goes back inside. And so it was that I rendez-vous with Cylinder five hours later.


    Still with Rudatte hanging from the ladder! The precious sample was saved

    11.4) Return to Iapetus base


    Now it's time to look for a way back to Saturn.

    Actually, I started looking and simulating trajectories already, which is why some of the screenshots below are dated year 135 while I met the "comet" in year 137.

    As it turn out, I have many different viable trajectories.


    Trajectory 1 to return to Saturn

    This trajectory uses a 1600 m/s burn to reach Jupiter in 20 years. Yes, it's a long time; the burn raised aphelion. By making those burns close, but not exactly on aphelion, I can slightly change aphelion, and thus change how much time I'll spend in this orbit and ensure I'll get a Jupiter encounter. Which is why I have so many options. Anyway, (after the purple course correction) Jupiter will eject Cylinder on the plane of Saturn. Saturn will still be lagging way behind, so Cylinder must be ejected on a higher apoapsis, to lose time and let the planet overtake it. It results in an intercept in 33 years. While the intercept is not ideal, we're far enough from the Sun that it's unlikely to result in too much intercept speed. And Cylinder will still have almost 4 km/s that can be used to help before aerobraking.

    This is a very safe and cheap trajectory. But it is slow, and time is malfunctions. So I keep looking to see if I can find some way to use my remaining fuel to save time.


    Trajectory 2 to return to Saturn

    This is a very extreme trajectory; it skips the Jupiter flyby entirely, simply raising aphelion enough to reach Saturn in 25 years. The high inclination, unfortunately, results in 12 km/s intercept speed. Further refining of the trajectory lowered it to 5 km/s (meeting Titan in the right part of the orbit makes a lot of difference, as does adding 1000 m/s of normal component to that 3 km/s burn), but it's still too much, considering that I will be out of fuel to slow down.


    Trajectory 3 to return to Saturn

    Trajectory 3 lowers aphelion with a 1450 m/s burn immediately, resulting in a Jupiter encounter in 10 years. From there, a direct trajectory to Saturn exhists - and it reaches the gas giant in only 23 years.

    Unfortunately, it has a high inclination. Cylinder will be coming to Jupiter very fast, it wll also leave very fast, which means I either get into a solar escape trajectory, or I get a high inclination.


    Trajectory 3, seen from the side to better appreciate inclination

    Still, this will result in a 5 km/s intercept on Titan, just like trajectory 2. But this time Cylinder will still have over 3 km/s, which it can use to reduce intercept speed. I know from the previous missions that the highest safe intercept speed on Titan is 3 km/s, which means I can spend 2 km/s to slow down, aerobrake at Titan, and still have 1 km/s left to reach Iapetus.


    Trajectory 3, detail of the Jupiter encounter

    This trajectory will make a 90° plane change at Jupiter, it will have to pass very closely. But it misses the greater death zone just enough to be safe.

    I later realized I could have done even better. My problem is that I must leave Jupiter as fast as I'm coming to it, and I'm leaving at high inclination to "burn off" some of that excess speed. However, once close to Jupiter - thanks to the titanic Oberth effect of the gas giant - it only takes 800 m/s to get captured. Meaning that I can use my engines to reduce that excess intercept speed, and get on a milder trajectory with less than 800 m/s.

    It would have been very hard to plan, though, because of the way maneuver nodes work. Any change in the nodes leading to Jupiter would have moved the Jupiter periapsis node away from periapsis, leading to a very difficult planning.

    As I said before, all the parts that were getting the most aging already broke, so for the next 9 years I got no malfunctions.


    The south pole of Jupiter. Io is still too far to be seen


    Periapsis, over Jupiter's north pole

    I could have taken the chance to send Fat Man to skim the upper atmosphere, and maybe from this polar trajectory a crew could even have survived. But without a dedicated spaceplane like Arrowhead, I'm no longer motivated to skim the atmosphere of the gas giants. Some of them now are completely unaccessible because of the radiations, and the others are way too big to enter atmospheric flight anyway. With those premises, touching the upper atmosphere feels kinda pointless.


    Trypophobia leaves Iapetus, preparing to meet Cylinder


    Cylinder reaches Saturn after 14 more years of space travel, without any further accidents

    Good thing I haven't had an outbreak of bug#22 ever since leaving the inner solar system, or those long Cylinder travels would take a lot longer.


    And it prepares to slow down before Titan aerobraking; it's still got 3500 m/s

    By the way, rocket braking before entering the atmosphere changes periapsis; I was ready to find the best trajectory by trial and error, but at the first pass I discovered that I'm actually coming fast enough, and I'm braking close enough to the moon, that periapsis changes only by a handful of kilometers. This pic is from the first failed attempt, showing a 430 km periapsis (way too high to brake enough). Second time I went again for 240 km periapsis and it worked fine.


    Entering Titan atmosphere at 6 km/s. A bit faster than the last time, but I still have a few minutes to slow down

    I forgot to take screenshots from inside the atmosphere, but I spent another 600 m/s to brake, so I was actually slower than I was when returning from the moons of Jupiter in 10.3.


    After aerobraking

    I came out of Titan's dense atmosphere with an apoapsis slightly higher than Iapetus. I could have reloaded and tried a few km lower Titan periapsis, but this is good enough.


    Trajectory to reach Iapetus

    This trajectory first requires to raise apoapsis. Yes, it is expensive, but if I lower apoapsis I won't get a close encounter with Iapetus for, like, 200 days at least. And by now Cylinder is relatively light, so I don't save much fuel. So this first apoapsis raising brings me to the purple apoapsis; the rest of the trajectory is invisible (should I add this to the bug list? Only if it repeats). That high apoapsis make me lose enough time that when I come back to periapsis, I can lower apoapsis to Iapetus level (362 m/s) and get an intercept.


    Still trajectory to reach Iapetus, this time also including intercept deltaV

    Intercept deltaV of 1200 m/s. I barely have enough fuel for it.

    As I said, I could have taken a cheaper, but longer trajectory if I was starved for fuel.


    Malfunction: an engine exploded during the Iapetus capture burn

    It's ok, I still had a third spare engine to replace the broken one.

    Meeting Trypophobia

    Cylinder has been away for 43 years. It had a bunch of malfunctions, but it handled the extended trip like a pro. Water level is very low in the last screenshot because I dumped some leftover water to save fuel.


    The docking dance ofthe landers is repeated, moving them to the top of Cylinder


    A Service probe is used to grab the last spare engine to replace the broken one


    Finally, Trypophobia and Cylinder are docked

    Cylinder is running on fumes, but Trypophobia got full while it waited. And now that there aren't anymore 4000 tons of fuel to lift to orbit, it doesn't have any deltaV shortage.


    And A'Twin lands on Iapetus, using only nuclear propulsion

    In retrospect, A'Twin didn't even need chemical engines. After I gave up landing on the Moon because it was too expensive, the bigger place I can land on is Triton. Which doesn't have any water because "rational resources" mod is anything but rational. After that, the biggest moon where A'Twin can land is Titania, a moon of Uranus, which is only slightly bigger than Iapetus itself. And it has a surface gravity of 0.033 g. A bunch of nuclear engines would have been totally sufficient to land in such low gravity, and it would have given Trypophobia a much better deltaV on its own, and it would have made logists easier - I still carry a spare cougar that I'm unlikely to ever use.

    Well, the current setup I used was good enough.


    With 8 reactors left A'Twin should produce 24000 electricity, but it's limited to 18000

    Damnit. Bug 18 is still striking. I have two more reactors that should work but are nonfunctional. Since those breakages are correlated to the reactors becoming broken and getting repaired, from now on whenever I have a non-critical malfunction on a nuclear reactor, I will reload the game and prevent the malfunction. Maybe this way I'll stop losing reactors to bugs, and will lose them only to aging.

    For now, I have to further reduce the conversion rate. It's still reasonably good even with six reactors. Actually, on both Titania and Pluto the ore concentration is low enough that six reactors are enough.


    A couple of nice pics taken during a maintenance trip


    I liked the way the "window" opened up to a glimpse of the ship's complicated interior


    Year 166, refueling done

    Previously it took 3 and a half years to refuel on Iapetus, now it took five years with broken up reactors. Hopefully it won't be a problem.

    Next I'll be moving to the outer solar system. DeltaV requirements are low, but travel times are getting high, and transfer windows are rare. But so far it looks like I'm lucky: Uranus is in a good position to reach from Saturn, and afterwards I'll leave Uranus with a transfer window to Neptune.

    Pluto is on the opposite side. Can't pretend too much. I already have ideas, but it will likely take a few more months before I can implement them. This update was slow in coming, my real life got busier lately.

    Bugs compilation updated


    A numbered list is so convenient to refer to bugs quickly. This list keeps growing. Problem and Solution

    1) Launching most vessels will crash the game. Must send them to orbit with alt-f12

    2) Ship will randomly get twisted about. Hope it's not too bad, or that it reverts spontaneously. In some cases it is acceptable to alt-f12 in a new vessel to replace the mangled one

    3) Loading the mothership in physical range gets increasingly more difficult, to the point that it crashes the game. Quit and restart the game every time you load the mothership

    4) Propellers start twisting around. No worry, it fixes once you stop time warping

    5) Orbit will get changed upon entering time warp. First warp to 10x, in any case save before warping

    6) Crew transfer function may get stuck. Saving the game often reverts the bug. If all else fails, transfer the kerbal by EVA

    7) Drills won't find ground even though they are on the ground. It goes and passes spontaneously, just accept that mining will take longer

    8) Ship occasionally sinks into ground upon time warping. Just try until it works. Updated: It was limited to Phobos, probably related to microclipping and the extremely low gravity

    9) Pieces get spontaneously detached for no apparent reason. Always check that part count does not change; reload if it does

    10) I can't plan maneuvers or go EVA, the game thinks my buildings are level 1. On starting the game, load the last quicksave instead of going on tracking station. If the bug manifests, restart the game

    11) Chemical plants stop dumping resources they were told to dump. Reset the dump option; doing it once per process is enough for the whole vessel

    12) Occasionally, kerbals will die for lack of power during time warp, even though power is always abundant. Reload when it happens. Updated: save before exiting time warp

    13) Radiation cover glitches during time warp, becoming ineffective even when the sun is completely covered. Set shielding efficiency to 100%, it cancels radiation damage

    14) Docking ports do not undock. This nasty bug must be fixed by editing the save file. KML editor has the function incorporated, I recommend it to anyone with this bug

    15) Actual reliability time is different from what it should be. Just check more often the parts that get broken more often

    16) Intercept on a target disappears randomly. I know the intercept is still there, I can manage with some piloting skill

    17) Crew hatch registered as blocked even though it wasn't, preventing crew from leaving Clamp. Had to move the docking port to free up a different hatch

    18) Some fission reactors are not working, even though they are not broken. Next time I actually break a reactor, I will revert the malfunction with a reload, and drop one of the nonfunctional ones

    19) "Time warp to here" sends me to the next orbit. Always double check on the time, and if necessary time warp manually

    20) Upon starting the game, clicking on the VAB does not work. Clicking on the icon on the bottom left corner of the screen still works

    21) Sometimes elements of the HUD change size. It doesn't affect the game, and seem to revert spontaneously

    22) Sometimes, when the vessel is not in physical range, the nuclear reactors on Cylinder will stop for no reason. Load Cylinder into physical range and they restart

    23) Occasionally, Nitrogenie in a Bottle starts spinning, even though its aerodinamic is balanced. Reload when it happens, and it will get fixed

    24) The ground on Titan has all sort of glitches and malfunctions. Be extra careful during landing, cheat the vessel in orbit before leaving it, jump to start flying. See 7.3 for more details

    25) Negative aerodinamic drag displayed on the user interface. Drag is still behaving normally, it's only the display that's bugged

    26) The docking port on Clamp has all kinds of problems, does not allow fuel transfer, can't be removed. I stuck another docking port there, and I can grab Clamp with a claw if needed

    27) Sometimes there is no signal for probe control even though there should be. Switch to the vessel that's not being seen, then back to the probe

    28) Crew pod of Hartman rover has a broken life support and a functional wheel, but it instead appears to have a working life support and a broken wheel. Nothing I can do about it; but it still works

    29) The sun shines through Jupiter's body as if it was part of the sky. It's just an harmless visual glitch

    30) An object on the surface coming into physical range may be loaded tens of meters above it. Hope nothing explodes. Reload if necessary

    31) Cylinder's central tanks gets refilled on (useless) oxidizer upon reloading; see 10.2. Dump the dead weight again

    32) All mining drills suddenly manifested a new uranium drilling function. Can't revert it, but they still work normally; it seems harmless

    33) The game is not spawning comets (always been active, but only became relevant now). For the comet landing, pick a large asteroid in an inclined, eccentric orbit and pretend it's a comet

    Broken parts recap


    I want to keep track of how much stuff I break, and how much it's affecting the mission, so I prepared a list

    Life support

    1 life support broken on Dolphin 1. I've got five more redundant pieces on it.

    1 life support broken on Dolphin 2. I've got five more redundant pieces on it. (NEW)

    1 life support broken on Cylinder. It's a redundant piece of a redundant piece. Least concern. (NEW)

    1 and only life support broken on Hartman. Sucks, I can't take extended trips, but the rover has enough air to conduct landing operations safely.

    1 life support broken on Fat Man. I've got five more redundant pieces on it.

    1 and only life support broken on Nitrogenie in a Bottle. No problem, it's not supposed to carry a crew any longer. (NEW)

    Nuclear power

    4 Excalibur reactors broken. Up to 4 can be lost before mining is slowed down - though it is already slowed by bug #18. There is concern here that they are breaking up fast. (+1 NEW)

    Reaction wheels

    2 large reaction wheels broken. I've still got 88 working.

    1 medium reaction wheel broken on Clamp. I've got a half dozen spare ones in storage.

    1 medium reaction wheel broken on Nitrogenie in a Bottle. I've still got a half dozen spare ones in storage.

    reaction wheel on the crew pod broken on Nitrogenie in a Bottle. Can't be replaced, but the other three wheels should be enough to keep the plane stable even if I break a lateral engine. (NEW)


    3 big nervs broken. I had three spare ones. If more engines are broken, the ship can work with less than the full complement. (+1 NEW)

    1 big wolfhound broken. I had a spare. Afterwards, the ship can work with less than the full complement.

    1 small nerv broken on Fat Man. I've got 2 more spares, then I can start cannibalizing Nitrogenie in a Bottle.

    1 cheetah broken on Spider. I've got 2 more spares.


    1 RA-100 dish broken. I've got 5 more redundant pieces. After that, I still have more non-relay antennas.

    1 HG-5 antenna broken on Wings B. I've got 1 more spare. After that, the mission can still use normal non-relay antennas.

    1 Communotron 88-88 antenna broken on Fat Man. It was itself a spare part, and I have more spares, as well as redundant antennas.

    1 Communotron 88-88 antenna broken on Wings A. I've got a few more spares; then I can cannibalize antennas from Trypophobia if really needed. (NEW)


    1 radiator panel broken. I had 12 redundant. They should be needed to vent heat from the nuclear reactors, but they are not actually needed anyway.

    Low-quality parts

    A landing light broken on Nitrogenie in a Bottle. Irrelevant, I don't need them.

    Life support on Trypophobia's gravity ring broken. Irrelevant, it only does pressure control and the same function is included in the greenhouses.

    1 Converter broken. Irrelevant, converter is the stock isru functionality that I'm not using. I need the chemical plant functionality, and that one is still working perfectly.


    2 reaction wheels broken on Milly. Now Milly has done its job.

    1 dart engine broken on the Mars Descent Stage. Now it's a pile of debris on Mars.

    Discounting the low quality and outdated parts, that's 26 critical malfunctions so far.

  17. 1 hour ago, stewake1306 said:

    I didn't think of the higher TWR, I used nuclear engines and it took me til I was out of the sphere of influence to rende.

    you can arrange a rendez-vous with nuclear engines too, and with ions - I've done it - but it's a lot harder; you've got to plan in advance, pass several kilometers in front of the other vehicle so that your gradual slowing down will get you closer to rendez-vous.

    but one step at the time; for now I'll teach you to do it with high thrust, low thrust later.


    How can I plan to get my periapsis to coincide with the other ship  at the right spot and right time? Trial and error?

    the thing about a high apoapsis is that a small push at periapsis will change your orbital time by a lot. You can use that.

    1) get your circular orbit with the same inclination of that of the target vehicle, and with the same height.

    2) make your orbit elliptical, with periapsis in the rendez-vous point. You must do this several days in advance, to have time to set up the next step

    3) for your next passage at periapsis, plan a prograde burn. The idea is to change your orbital time so that your next passage at periapsis will be timed exactly with that of the target vehicle.

    For example, target vehicle will pass there in 2 days 3 hours 15 minutes? Then you must burn so that your next orbit will have a time exactly of 2 days 3 hours 15 minutes.

    You don't need to make calculations, because once you are close enough the game will show you the close approach.


    Unfortunately I don't have a good picture to show this exact process - it's been a while since I needed to use it. But I can show a similar picture, only difference is that in this case I was coming from a higher orbit.


    so, the vehicle to be rescued was traveling along the light green line. the rescue vehicle is labeled as "Eve mission + comet catcher". It's in high orbit around Minmus.

    First thing I planned the yellow maneuver. It raised my apoapsis, and that was made to change the orbital time.

    Then the purple maneuver. Ok, there are two of them, the one on the left for 8.2 m/s. That's a plane change, because I had yet to fix inclination.

    Finally the purple maneuver on top (17.8 m/s) to lower periapsis so that it touches the trajectory of the stranded vehicle. and you se, it says intersection at a distance of 0.2 km. That happened because my first burn prolonged my orbital time just enough that I'd fall down to periapsis with the proper timing.

    this was actually more difficult than the maneuver I'm suggesting you, because the time depended on two different maneuvers and not only on one.

    54 minutes ago, LHACK4142 said:

    KSP has a pretty good rendezvous and docking tutorial, so I'd just do that. Maybe play it 2 or 3 times, but you don't strictly need to.

    the rendez-vous tutorial is good for a vehicle in orbit. but it doesn't help with a vehicle on a hyperbolic trajectory.

  18. Part 5: missions missions to everywhere, none of them arriving

    Dealing with a bunch of correction maneuvers. Most noteworthy thing is the launch of a new scanner/relay for the Eeloo mission


    The Eeloo mission ejects a first couple of drop tanks


    The conjoined spaceship uniting all three ISRU missions is launched to Minmus. Meanwhile, the ship with the engineers is sent on its journey to promote them.


    First on Mun, here separating from its extra tank


    Then to go in solar orbit, and return to Minmus

    This trajectory wasn't easy to set up. I sent the ship away from Mun with enough speed to reach solar orbit in a few days, then as soon as I get outside Kerbin's SoI I make a large retrograde push to return to Kerbin. Had to add some radial components to avoid missing it, an operation that was complicated by being unable to select Kerbin as target while in Kerbin orbit. And I had to time it all to hit Minmus on the way back.

    The fuel available is barely enough to perform the mission, which is no coincidence; I could eject faster from Mun to save time, so I set things up to use all the fuel I have and be done as fast as possible.

    Eight days later, the engineers are returning to Minmus, while the ISRU multimission is already waiting for them.


    Trajectory to rendez-vous the ISRU multimission with the engineer promo mission

    The trajectory looks complicated, but it's really just a small plane change and a couple concentric orbits to syncronize the arrival of the two spaceships at the same periapsis at the same time.


    Rendez-vous. Transfer to be done by EVA, because I didn't think I could grab the engineers ship with a claw

    Rendez-vous was at day 18. This time, with high level engineers, it only took 4 days to refuel. The ship is ready to go on day 22.


    ISRU multimission full, ready to leave Minmus


    Jettisoning the lab, now that it's done its job of promoting the crew


    Removing the nose cones. I should have done that before landing, but it's a small difference


    In Minmus orbit, separating the ships

    Now the three missions can take different paths.

    First of all the Eve mission.


    The Eve mission trajectory to Eve

    Eve is passing in front of Kerbin right now, meaning a transfer window just closed and there won't be a new one for a while. So I have to transfer outside of a window - something not unusual in this career. I push solar periapsis lower than Eve, to catch up with the planet. It's quite expensive  (1310 m/s) because from Minmus I have negligible Oberth effect. Once at solar periapsis I lower apoapsis (701 m/s), arriving at Eve at solar apoapsis; this reduces intercept speed at350 m/s. Without this maneuver - if I had just lowered solar periapsis and crossed Eve orbit - I would have needed 1400 m/s to leave Minmus (would have needed a lower solar periapsis) and 1200 m/s Eve intercept, for a total of 2600 m/s; this way I need only 2350 m/s. Doesn't seem much, but the Eve mission is intended to be a multistage Eve ascent vehicle; it doesn't have much deltaV it it's got to stay whole, and it must land on Gilly before it can refuel again.

    The comet catcher, instead, had to be scrapped. In part 3 I had a nice comet to reach, but after I reloaded to remake the mission, it spawned in a different - and very inconvenient - spot. You can see it on the left of the image on the previous pic. It's behind Kerbin, going slower, so to catch it I'd have to make a tour around the sun, lowering periapsis to be faster; this is what I've done for both Eeloo and Jool. However, to reach those planets I had a huge amount of deltaV. This time I have much less, and it's not enough. I also tried to see if I could get a gravity assist from Eve, but the inclination is all wrong, I'd have to make a 20 degrees plane change in low solar orbit. While I could catch that comet with some longer trajectory, I can't return it to Kerbin in two years. And no other comets spawned.

    Well, the challenge didn't specify a comet, so I can skip this mission.

    As for the asteroid, I have one intercepting Kerbin in day 205.


    Asteroid catcher, first part of the mission

    The first part is just matching inclination. It's a high orbit, so even a big inclination change is not too expensive.


    Second part of the asteroid catcher mission

    And then it's just a matter of playing with orbital times to syncronize my passage at periapsis with the passage of the asteroid.

    I launched a new Duna mission, this time made a bit better than the previous one. It's probably got way too much fuel, but money is not an issue.


    The Duna mission

    The Duna mission will wait in orbit until the launch window.

    Now it's time for some assorted course corrections and other intermediate maneuvers. First of all, the Eeloo mission.


    Eeloo mission at perihelion

    The Eeloo mission has reached perihelion - also fulfilling the "low solar orbit" condition - and has to perform a fairly large maneuver to reach Eeloo. Here shown in all its glory; this close to the sun, the solar panels are just shy of overheating.


    Looks good

    Now it's time to refine the trajectory. Which is very hard, because the game does not cooperate. It can't find intercepts the regular way.


    Here you can see the game is giving me an intercept in the past - telling me close approach was 257 days ago

    I set about to do it by trial and error; I try a bit of a radial burn, time warp one year, and see how close I am to Eeloo. 200 m/s radial is not enough, I pass in front of Eeloo. 250 still in front. 330 I'm now passing behind Eeloo... Eventually I find the right amount of burn to get an intercept.

    However, intercept speed is very high - 12 km/s - and I'll also need a lot of deltaV to return back. I'm no longer sure I have enough xenon, so I reduce mass by ditching the relay.


    Eeloo mission ditching the scanner/relay

    If you remember, it was faulty anyway, requiring to stay with the ship to have enough battery to perform its mission. By removing it, I gain over a km/s. Of course now I have to send a new one.


    The new scanner/relay for Eeloo


    It has to be launched vertically due to poor aerodinamics. A fairing would have been too large and heavy anyway


    And its trajectory to Eeloo

    This time I can take a less breakneck trajectory, because I don't have to plan for a return. I can arrive in one and a half year. And I have a lot more deltaV than I'll actually need. Since this trajectory is more sane, the game also finds intercepts a bit more easily.

    Other missions go on. Here we have the Moho mission jettisoning the chemical stage (which still had some leftover fuel after leaving Kerbin) during the plane change.


    Moho mission jettisoning the last chemical stage



    Moho mission, updated trajectory to Moho

    And then it's finally time to launch the Duna mission. I don't use a pure Hohmann transfer, to save some time. Still, the mission has plenty of fuel and plenty of time available.


    Planned trajectory to Duna

    The Eve mission performs its plane change to align to Eve.


    Updated trajectory to Eve

    And then it's time for a big maneuver on the Jool mission.


    Jool mission, jettisoning the chemical stage

    This was made difficult by wobbling; the version of ksp I'm using still suffers from some strutting bug, where it won't make struts between docking ports - something that caused no small amount of nuisance in my caveman Jool 5 mission. I'm using the same install. I had to reload back and use an engineer to salvage a strut from the chemical stage to hold the Tylo lander in position.


    Jool mission, using the ion engines

    For propulsion of this mission, instead of including a special stage, I decided to add a couple of ion engines to the Tylo lander (which will be removed by an engineer later) and use it to propel the thing.


    Planned arrival at Jool

    As you can see from the picture, I'm using a gravity assist from Tylo to reduce the speed a little bit, but I'll need a large maneuver to capture at Jool. This will be a hard mission to pull off, requiring great timing for all the landings.

    I'm having the additional complication of lacking xenon. Oh, there's plenty to reach Jool, but I was planning on leaving a couple tons for the return stages. This included a healty extra, which I will have to use for capture around Jool. Well, nothing I can do about it. I will just have to do my best with whatever xenon is left after capture.

    The Eve mission is about to perform its last course correction. Time to also plan a Gilly encounter.


    I can regulate inclination to match Gilly's orbit

    The Eve lander still has 1450 m/s, it will be able to reach Gilly without problems, halfway through year 1. No worries there.

    A few more days, and I have a complication: the asteorid catcher and the Eeloo scanner/relay have a planned maneuver at the same time.


    Planned maneuver at the same time

    The Eeloo scanner/relay is making a long burn on ion engines in solar orbit, so it's less time sensitive. I split its burn in two hales, first half done first, then I swap to the asteroid catcher - whose maneuver is time sensitive - and finally back to the Eeloo scanner/relay to finish the 6 km/s burn.

    To sum up the various missions:

    - Eeloo: low solar space achieved. Well set up for arrival at the end of year 1. Should have 10 km/s left afterwards (including jettisoning the lander).  Feels safe.

    - Jool: xenon level low. Uncertain whether I'll have enough left for a timely return on Kerbin.

    - comet catcher: mission scrapped for the comet being in a too bad orbit; wasn't required by the challenge

    - asteroid catcher: on its way, feels safe.

    - Dres: safely on its way, no problem anticipated

    - Duna: safely on its way, no problem anticipated

    - Eve: ahead of schedule, no problem anticipated

    - Moho: safely on its way, no problem anticipated

    So all looks good except the Jool mission, and possibly the Eeloo missions, which may have to eat up too deeply into their xenon stocks and may not have enough left to return to Kerbin fast enough. We'll see.

  19. 8 hours ago, stewake1306 said:

    So... I successsfully got some science from Eve and was able to get my ship back to Kerbin. However, the shuttle burns and explodes during re-entry! I also do not have enough fuel to circularize around Kerbin once I get into the sphere of influence.

    I have my ship passing by, and I'd like to somehow transfer crew and data to another ship as it near periapsis around Kerbin. I tried to send a ship with a better module for re-entry to rendezvous, but this left me with another ship in solar orbit with no fuel to get back to kerbin.

    Is there a better ay to "catch" the ship or crew as it's passing by? It is flying by at 4k m/s at about 150k altitude.



    at that speed, you are too fast for aerobraking unless you have good thermal shielding, but you can send another ship to rendez-vous.


    a few days before periapsis, send up a new ship with enough deltaV, and with high twr (because it will have to make large maneuvers fast). put it in an elliptic orbit so that its periapsis coincides with the eve mission periapsis. set your apoapsis so that it will pass at periapsis at the same time as the other ship. get a rendez-vous. transfer the crew on this new ship. then slow down

  20. 4 hours ago, jimmymcgoochie said:

     I got almost 1500EC/s per Gigantor solar panel on the way into Moho's SOI at a distance of less than 1.5Gm from Kerbol and with Moho's weird little equatorial radiation belt thrown into the mix it wasn't a very nice place to be.

    solar irradiation has got nothing to do with radiation. you see the radiation level in the main kerbalism window. and it's actually always the same everywhere in solar orbit: 0.013 rad/h. it will kill the crew in roughly 3 years without shielding, 10 years with full shielding at hard level. an active shield will completely cover that amount of radiation.

    there is no special radiation hazard on moho other than its radiation belt


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