king of nowhere

August 28

1 minute ago, JeDoesStuff said:

As requested, here is the post I had mistakenly made on the old thread:

So I thought I had sent this before, but I have bested my 30 ton SSTO with an 11.215 ton SSTO

I checked it, and your entry doesn't just violate rule number 2, it murdererd its entire family and danced on their corpses. Your submission will go to honorary mentiones.

By the way, I see you have a nerv, a rapier, a convert-o-tron. those together are 6.5 tons, including the drill.

You also have room for 10 tons of fuel. Did you start with fuel tanks half empty? You should provide proof. If you run for low mass, you should start with some way to have the mass clearly on display. Just opening the deltaV tab on the lower left corner would display the mass.

I don't want to sound too much like a pain-in-the-ass. It's still an impressive spaceplane.

August 28

30 minutes ago, JeDoesStuff said:

So I thought I had sent this before, but I have bested my 30 ton SSTO with an 11.215 ton SSTO

Note: part clipping was used here, but iirc there arent any other exploits used besides needed to go to the tracking station because for some reason the ISRU was trying to radiate through the kerbal

This thread is now outdated, there is a new jool 5 thread

I will review your submission, but for the sake of having all the stuff in one place neatly organized, please post in the other thread

P.S. sorry to disappoint you, but the current record for low mass is 5.2 tons. Your result is still very good, though

August 27

Part 9: To brave the open space

Paleodiastimoploio reaches Duna. Everything goes according to plan, except for one slight, grave miscalculation.

Duna is visible above the tank train

9.1) Tools and calculations

Spoiler

My original plan was to launch at the transfer window, then use the next orbit to refine the encounter. This would have required circularizing orbit in solar space, and spending one Duna year to meet the red planet.

I realized I can do better. If I launch after the transfer window, I will pass well behind Duna on the first orbit, and I will have to catch up in the next. This means that I won’t be required to fully circularize orbit in solar space, but only to raise it just enough to ensure an encounter. I may even be able to get some Oberth effect, or even some aerobraking done. And I will spend less time in space with the crew, with the radiaton clock ticking.

The Kerbin-Duna transfer is a 640 days orbit. Launching in the launch window, I will reach solar apoapsis when Duna will pass there. Then, if I don’t change anything, I will return to the same spot 640 days later. Duna will return to the same spot 802 days later. If I want Duna to be in front of me, so that Duna will reach my spot in 640 days to minimize the need to burn in solar orbit. But I’m on Kerbin, which moves differently than Duna; I can’t just launch 160 days earlier. How to calculate it… Ok, got it.

By the alexmoon tool, I can see that there is a 920 days interval between two Duna transfer windows. This tracks the relative movement of Duna and Kerbin; in this time, Kerbin will make a full orbit relative to Duna, returning in the same relative position. So, to miss Duna by 160 days, I want to miss it by 20% of an orbit, 72°. It means I have to leave 20% of the time before the launch window. 20% of 920 days earlier, so 180 days before the transfer window. And at that time Kerbin will be 72° behind the ideal transfer geometry.

But I won’t be very accurate with the apoapsis, and I want to make sure I will have to raise solar periapsis a bit to reach Duna. This will safe guard against needing to lower periapsis, which will cause to both spend more fuel and increase intercept deltaV. So we’ll start somewhat later than that. Let’s say 120 days before the transfer window, that should be safe.

Of course, I am stuck with a 24 hours clock, so it will be 30 days for me. In my 24 hours clock, the next transfer is at 1:290, and I will go at 1:260.

Finally, if I want to perform the transfer burn with any accuracy, I need to gauge 1100 m/s exactly. No, I can’t just keep accelerating until I reach 3400 m/s, because Paleodiastimoploio will be going away from Kerbin by the time the burn is done, so its speed will get lower. For this, I built the final tool – just a few lines of calculations in my excel datasheet, really. It calculates the speed I should have at every altitude. If I want a 1100 m/s burn, I enter 3400 m/s, which is the speed I should have if the burn was istantaneous, and I enter the actual altitude. The tool then calculates the sum of kinetic and gravitational energy and returns the speed I should have at that altitude. So, when I’ll be in a Kerbin escape trajectory, I will pause the game, input my current altitude, and check with the tool if I should accelerate some more or if I’m good.

For fun, I tried to integrate the gravity formula myself, but I discovered that my calculus is very rusty, and I had to get some hints from the internet.

9.2) Didn’t think this through

Spoiler

Paleodiastimoploio has a TWR of 0.3; it will take around 6 minutes to perform the transfer burn. In the last chapter I said it was fine, but it really is not. With an orbital time of 32 minutes, starting the burn 3 minutes earlier means a 34° angle. Not only cosine losses are quite high (that part, I was ready to accept) but the burn will be less accurate overall, especially because I don’t have any reference for where the theoretical istantaneous burn should actually happen.

I could send another couple of Poodle engines, but I got a daring idea. I said that raising apoapsis gradually is off the table, because it would expose the crew to multiple passages through the radiation belts. But! What if I sent Paleodiastimoploio alone to raise apoapsis, then I’d bring the crew later? For this plan, I need a crew shuttle with lots of deltaV, which I achieve by strapping drop tanks to it. I rendez-vous with Paleodiastimoploio, but don’t dock. I raise apoapsis on Paleodiastimoploio, until I achieve an orbital time of 64 minutes. Or 96. This puts Paleodiastimoploio in a resonant orbit with my crew shuttle, so that it will go back to periapsis right when the shuttle is passing there. So I can dock – using all the extra fuel to speed things up – and finish the transfer burn.

The shuttle designed for the task. It's got a lot of deltaV once the six boosters are strapped on

Only halfway through launching the shuttle I realized there were several problems with this idea. The main one is, I will dock with Paleodiastimoploio at periapsis. A bit later, because docking maneuvers still take some time. To finish the transfer burn properly, I’ll need to start burning before periapsis, not after. If I make the final burn after periapsis, it will alter my direction.

I also realize this plan will require the crew to be in orbit in an unshielded vehicle, exposed to radiatons for a while. Just the background level, but it still hurts over time. Putting shielding on the shuttle would lose too much deltaV.

As I’m wondering whether it’s worth salvaging this plan, I realize I forgot to put solar panels on my shuttle.

And electricity will run out in one hour

So I abort the mission.

And I send up another couple of Poodles, see 7.1 for the launcher. Their mass will be negligible, unlike the cosine losses I’d have suffered without them

Too bad for the elliptic rendez—vous, it was a good idea.

No. No, it really wasn’t.

9.3) All aboard! Next stop, Duna

Spoiler

After sending the crew in a shuttle with less fuel, but with solar panels, I am ready to start. I need some more calculations for the timing, though.

The alexmoon planner says I have to make the burn 152 degrees from prograde. I could eyeball, but this transfer burn is important, everything I can do to improve its accuracy is welcome. I’m helped by the fact that the prograde-retrograde direction respective to the planet falls exactly on the terminator line.

Unfortunately, the line is not defined enough to use as a reference. You try figuring out where it falls exactly in this!

So I tried to use solar panel output. If I have the ship pointing prograde, when it passes over the terminator, the panels on the back of the sunshield will have 100% output.

Turns out that’s not an ideal answer too, because those solar panels are tolerant of slight misalignments, they keep 100% yield for almost a minute. But I can still fix this: I chronometer the time those panels will spend at 100% output, then when half that time has passed, I will know they are perfectly perpendicular to the sun.

Before implementing this plan, though, I discovered a simpler way.

The two drop tank trains are so narrow, they almost make up a pinhole gnomon!

With the sun equidistant from both tanks, and the ship holding prograde, I can confidently eyeball I'm 180° from prograde, with a margin of error of no more than a couple degrees

Ok, here I am 180° to prograde. I must center the burn at 152° to prograde. Wth an orbital time of 1916 s, angular sped 0.188 °/s, it’s 149 seconds from now. With the improved TWR of 0.5, it will take 220 s to perform the burn, I must start 110 second earlier. So, burn in 39 seconds, at 06:08:44.

I wanted to also include a screenshot for using the tool to determine when to shut down the engines, but what am I going to show? Paleodiastimoploio with engines shut down?

Finally I can discard the spent tanks

To install the extra Poodles, I was forced to keep a few tons of empty mass. This increased consumption by 4 or 5%. Taking cosine losses from lower TWR would have resulted in at least 20% increased consumption, though.

And radiation is 0%. The passage through the belts was so fast, the crew got less than 1% damage. Considering that every 1% damage means 20 or so less days that the crew can spend in space, that's even more important than saving fuel.

As for how the burn went...

Wow, it was incredibly accurate. So accurate, in fact, that the 50 m/s I included to account for inaccuracies made me overshoot Duna instead. Well, that, and hitting Duna at its periapsis; on average, my burn would have been flawless. I had to burn 80 m/s retrograde to reestablish a proper Hohmann trajectory. As for inclination, Kerbin and Duna are similar enough, there's no need for a plane change. Besides, I actually tried to fix inclinations, but without a functional tracking station I am limited to eyeballing, and I concluded it's not accurate enough to improve on my current orbit.

I am so proud of my work with a datasheet. When I go read my previous diary, and I see my encounter plans were something like "set an orbit to cross the target, and wait for a chance encounter", I marvel at how much I learn.

Paleodiastimoploio tanking a solar storm with no increased habitat radiation

I turned storm probability way down, because during a storm I must time warp at x1000, else the game glitches and irradiates my crew regardless of the sunshield. And those storms are very frequent, and last for seven hours each. They are just a huge bother. But turning them off completely felt wrong.

9.4) How I shoot myself in the foot

Spoiler

To calculate the encounter, I need to take the exact times at which Duna, then Paleodiastimoploio, will pass at the encounter point.

The passages. As well as a radiation report on Paleodiastimoploio

Duna passed at the intercept point in day 307.5, Paleodiastimoploio passed on the same spot in day 329.25 (more accuracy with the hours is pointless, as I can’t be sure I have the exact same spot anyway, and the method is robust enough to account for it). A difference of 21.75 days, or 87 Kerbin days. Duna has a orbital period of 801.5 days, to syncronize I must raise Paleodiastimoploio to a 714.5 days orbit. Entering that in the tool, I have to raise periapsis to 18870 Mm. Having intercepted Duna in its periapsis is working against me here. But the initial fuel calculation accounted for an even less efficient maneuver, I should be fine.

As for radiation, at the current rate I should get around 40% irradiation when reaching Duna, consistent with previous calculations that I should have time to bring the crew back, if barely. My higher tech kerbalism missions didn't have this problem because the active shield cancels background radiations, and decontamination units revert their damage. But without those technologies, the small amount of background radiations will kill the crew in roughly 5 years.

Traveling is fine, just a couple of minor accidents.

A solar panel broke. I got 24 for a reason

The reaction wheel of the probe core broke. I didn't need it anyway

Why does it seem like I'm a bit too far behind the planet?

After a long orbit around the sun… I miss Duna by 4 days

I can barely catch a glimpse looking out of the window at maximum magnification

I am flabbergasted. All my tools, all my calculations up to this moment far exceeded any accuracy expectation, and now this. What went wrong? Duna actually got into the same spot after 800 Kerbin days, that part was correct. The timing I took for the passage was good.I used this same calculation to return from Jool, twice, and both times I got within 6000 km of Kerbin. I double-checked all tools and calculations, all is fine. Desperate to figure out what went wrong, I cheat all structures to level 3, and I find a discrepancy between my orbital time and the one calculated by the tool. But I used Duna to tune the tool, and it calculates its orbital time exactly…

I used the values in the wikia. Does this mean that the wikia has wrong data?

....

NOOOOOOOOOOOOOOOO!!!!!!!!!!!

The Duna page in the wikia, which I used to get its orbital time, reports the periapsis and apoapsis as distance from the center of Kerbol. Unthinkingly, I put those values into the equation, which was set to work with distance from the surface, as the game uses. And it returned a too-high value. Trying to figure out why it did, I came across the solar radius. If I remove a zero from the solar radius, the orbital time for Duna becomes correct. So I concluded that the solar radius was missprinted in the wikia, removed that zero, and used the tool.

I even considered that I used the same tool, with the same numbers, to return from Jool; but, lacking other explanations for why the orbital time of Duna returned by the tool was wrong, I concluded that coming from Jool, very high orbit, the solar radius must have been negligible on an orbit so long. In fact, I was so convinced my data was correct, I was about to post in the forum on how the game wiki has the solar radius wrong.

What actually happened is that without a zero, the solar radius becomes negligible enough, so the orbital time calculated for Duna becomes correct within a reasonable error margin; I didn't bother writing more than four significant digits for every number, I assumed any small inaccuracy to be caused by that. But this oversight removed 260000 km of radius for the spaceship, throwing off the calculations by 16 Kerbin days. Thus fixed, my tool reports I’d have needed a periapsis of 18400 Mm. At this point I’m curious, and I already got the level 3 structures, so I check… Yes, I get a very nice intercept with this value. I get a Duna encounter with periapsis between 18300 and 18450 Mm, so my calculation was pretty spot on. The tool worked perfectly. And the methodology is robust enough to account for an error of up to a couple days.

I did a lot of difficult calculations and I did them very well and I was so proud of myself. Except for the part where I calibrated the tool with the wrong data.

Now I know how those engineers that crashed a probe on Mars due to an error with units of measurement felt. Well, except the part where I crashed an actual probe that costed actual money and most likely sunk my actual career. But the whole "I am a dumbass and should have totally seen it", that's there. It's not an error of unit of measurement, rather an error of reference point, but just the same, it's a silly error on how your data is measured.

Sigh. Well, let’s reload and see if I can at least get the challenge done with one instance of reloading.

9.5) How it should have gone

Spoiler

Luckily, even if this was supposed to be a nanodiamond run - therefore, no save-reloading allowed - Paleodiastimoploio still has the nasty habit of occasionally exploding for no reason. This, in turn, gave me the habit of saving regularly, at least when that cursed mothership is in physical radius. So I could reload to the previous apoapsis, and make the correct burn, with a 18400 mM periapsis.

Then I waited another two Kerbin years. Malfunction time is determined randomly when a part is spawned, so the same parts broke at the same time.

I also got a stress-related malfunction that broke a Geiger counter. I brought two for one such event

This time, the encounter looks right

I can see Duna from the window, but this time I'm moving straight towards it

I got a 15 Mm periapsis, reasonably close

Inclination is also not too bad, I will fix it from apoapsis once I'm in orbit. Radiations are excellent, 38%; if the return trip takes as long as this one - and it should actually take a bit less, because I will be in a lower orbit - I should be good.

After some deliberation, I decide to go for aerobraking. I'm slow enough that I know even the fragile parts can take the heat. My main issue is that, the challenge including a "no reload" policy (well, except for catastrophic damage), I can't find the right periapsis by trial and error as I've always done. I know Paleodiastimoploio is extremely draggy due to its sunshield, and don't want to accidentally crash on the planet. I decide to play it safe; I've been aerobraking on Duna often enough, and I know that before 30 km of altitude, there's very little drag. A 35 km apoapsis will slow me very little; I may have to still spend some fuel to finish capture, but I'll still save something, and I won't risk braking too much.

I changed periapsis by pointing inward and burning. By the fuel gauge, I spent 150 m/s on it

One thing I did NOT think about was avoiding Ike. Fortunately, I narrowly miss it, or I would have been forced to make expensive corrective maneuvers

As I take science, I start discarding science modules. Those are the main sources of spontaneous explosions, I can't wait to get rid of them

I exited with a 3000 km apoapsis, which works wonderfully to fix incliation

Having experimentally determined that a passage with a 40 km periapsis will lose some 20 m/s, I slowly aerobrake the rest of the way to a near circular orbit.

The original plan called for arriving at Duna with 95 tons of vehicle left, and I have 115, having saved 20 tons of precious fuel. They will make the return trip easier. Radiation levels are as expected. Food consumption was a bit bungled, I should have added some more. If I had a stress accident where I lost 10% of my food, it could jeopardize the mission. Anyway, I still should have enough to return, even if one such accident occur.

As for stress itself, the crew is holding up surprisingly well, considering that they miss many of the amenities unlocked by higher tech, like artificial gravity, plants, a cupola, the ability to call home; then again, my multi-decade missions gave me a bit of a skewed perspective on how much of a problem stress is. Water levels are very good, I ended up not needing the Sabatier reaction - I could have saved the weight and part count.

Next, exploration begins.

August 26

7 hours ago, Poppa Wheelie said:

Do Jool 5 missions done in KSP2 count? If so, I think I have a Jeb's Level mission here.

Maybe a different leader board for KSP2, if you want?

a ksp2 challenge goes in the ksp2 forum.
although i don't see a jool5 in the ksp2 forum - rather, i see one, but it includes flybys. very weird. try asking in the ksp2 general subsection, maybe.

August 25

5 minutes ago, darthgently said:

I've always wanted to build a very simple but very efficient heat exchanger for solar water preheating via a winter friendly medium like alcohol or antifreeze. The design I've settle on is simply a very long length of copper tubing inside a very long length of a bit bigger diameter tubing (PEX?) with the fluids running in opposite directions. I figured 3D printed spacers that keep the inner centered and not touching the outer tube while still allowing good flow could be figured out and the tubing could be loosely coiled and surrounded by insulation in a box

you know, that's exactly the kind of problem my students are expected to be able to solve at the end of the topic.

except it misses several important details. namely:

- how much water you want to be able to heat? for a shower, you need a flow of 0.17 liters per second, if you are happy with slowly filling a tank, it can be less.
- by how much you want to heat that water? do you expect your design to raise temperature by 10°C? 20°C? that, and flow, will determine the amount of heat exchanged. of course, the upper limitation to that is the heat that can be generated by your solar heater.
- I'd also need the diameter of the inner copper tube
give me those data, and I can calculate something.

but as a very rough start, a system like that should be able to exchange roughly 1 kW of heat per square meter of surface of the copper tube per degree of average difference of temperature between the flows. I'm using 3000 W/m²K as convective coefficient for water, as a table i found claims it's a typical value for water in forced circulation. I'm using the same value for alcohol, because i can't find an appropriate value but it can't be too distant from water. you can use that to calculate how long the tube needs to be depending on how much heat you want to exchange

August 25

13 minutes ago, Codraroll said:

My best guess: it's a problem that needs to take into account a lot of factors for accurate calculations, and many of those factors can be hard to obtain good data about in operation. That means the calculation has to rely on assumptions piled on assumptions until you can't really create a reliable answer. So the whole complicated problem, including the maintenance frequency, is simplified to a single factor and counted as a constant inefficiency. The average of a sort of "sawtooth curve" as the heat exchanger is fouled over time and cleaned occasionally. The factor you end up with could be based on some old research projects or a collection of industry data. Such things are done all the time in standardization, and it can be quite a rabbit hole to dig up the original source of a number.

yes, that's my best guess too, but it should still include the information "how often are you going to clean up the exchanger". without that information, a fouling factor is kinda useless. and that information is not included in any source i could find, and even the best case only mentions that time is a factor without being any more specific.

P.S. you don't want to take the average of a sawtooth curve. you want to take the worst performance possible. because your chemical plant will have to keep working up to the point when you clean up the thing

August 25

I admit, it doesn't have much to do with kerbal space program, or with space in general. But this forum is the best collection of nerds and stem-oriented people I know, and it was exceedingly useful in providing answers when I had an issue with cryogenic cooling. Besides, I'm doing this for a group of kids. Somebody think of the kids!

I am a high school teacher of chemistry, preparing a lesson on heat exchangers. My university curriculum was more on organic chemistry, I'm not a huge expert on the topic, and the textbook is not helping.

So, fouling factor. Your heat exchanger is going to get dirty, so you have a fouling factor to deal with that. it's a simple addition to the heat exchange coefficient.

However, the problem I have is that I expect fouling to build up with time. I would expect a fouling factor to have a buildup per day, showing how your exchanger becomes less and less efficient with time, until eventually it's time to clean it up. You could also use one such formulation to determine heat exchanger size depending on how often you want to run cleanup. But no, fouling factor is a simple factor that doesn't account for time at all.

I've been looking in the internet, but that's the kind of very specific stuff that's hard to find. I found lots of textbooks, but none mention time. The best I got is this quote

Quote

Practical design of heat exchangers

Plate heat exchangers are often an economical solution if corrosion resistant materials are required. The deposit forming is usually considered by calculating an excess heat transfer surface. The size of the excess surface margin must be as high as the heat exchanger can be used a reasonable time.

TEMA shell & tube heat exchanger

For the calculation of the initial excess size of shell & tube heat exchanger is the guideline with the fouling resistance terms of the Tubular Exchanger Manufacturer’s Association (TEMA) useful.

Other heat exchanger constructions

Plate Heat exchanger Caused by a higher turbulence plate heat exchangers leans to a lower deposit forming as shell & tube heat exchangers.

An examination of the deposit forming in plate heat exchangers and shell & tube heat exchangers with produced cooling water has the result that a plate heat exchanger with a velocity of 0.45 m /s has only one third of the deposit forming of a shell & tube heat exchanger with a velocity of 1.34 m/s. An examination with black liquor (67% solids content) shows a deposit forming in a double tube heat exchanger during 2 hours.

The parallel running plate heat exchanger was free of deposits after 24 hours. Nevertheless the heat transfer coefficient of plate heat exchangers e.g. in the dairy industry went down around 30% during one day.

Caused by hygienic reasons and the resulting recurrent cleaning cycles is fouling in this kind of industry a secondary problem.

Typical heat transfer coefficients of plate heat exchangers are around 6000 W/m²K compared with this are the heat transfer coefficients of shell and tube heat exchangers around 1500 W/m²K. Caused by these different heat transfer coefficients it is not advisable to calculate plate heat exchangers with the fouling resistance of shell and tube heat exchangers. With an exemplary fouling resistance of 0,15m²K/kW is the surface margin of a shell and tube heat exchanger around 22%. For the same example the surface margin of a plate heat exchanger will be 90%.

There are different recommendations for the fouling resistance of plate heat exchangers. In general the choice of the fouling resistance should result an over sizing of the plate heat exchanger below 25%.

underlined by me the parts that are more useful.

this piece acknowledges that time is an important factor, and that the exchanger will become less and less efficient until it has to be cleaned up. However, it doesn't in any way help with determining how often you have to clean it up.

It's like the fouling factor assumes that you are going to clean the exchanger regularly, before the efficiency drops even lower than the factor would suggest. But it doesn't in any way help determining how often that cleanup must occur. Once per day? Once per week? Once per year? I would assume that in the dairy industry you will need daily cleanings for hygiene purposes alone, so it's pointless to design a heat exchanger to work more than 24 hours without maintenance. But in the oil industry, you'd rather keep the machinery running for as long as you can, having to stop a whole distillation column daily to clean it would be unacceptable, and therefore you'll want them to run longer; possibly as much as a year, so you can shut down the plant during summer for maintenance, send most of the workers in vacation, and have the maintenance team clean. But how that affects fouling factors? are the fouling factors for food liquids calculated over different times than those for oil?

or does fouling eventually stabilize to a certain level of inefficiency? is the R factor a kind of asymptote to which the fouling tends? but in that case, why do regular cleanups, if it's not going to get worse?

The way the textbook simply dismisses the problem by giving the formula with the fouling factors is extremely confusing.

For the sake of preparing a better lesson for my kids, I hope in this forum there's some engineer with specific knowledge in the field that can answer.

August 25

Part 8: Giving the rocket equation its due

Sending up all the fuel for Paleodiastimoploio.

Also, Paleodiastimoploio is finally finished. At 230 tons and 550 parts, it's way bigger than I was expecting

8.1) Propellant for the propellant god

Spoiler

Now that I sent in orbit everything I need for the ship to work, I must perform some calculation for how much fuel I will need.

Normally, 1 km/s is enough to reach Duna and aerobrake. Not so when you can’t set maneuver nodes. I need a sufficient amount of fuel to account for the flight plan. But since every 5-ton drop tank sent to orbit requires 40-50 minutes of work, I’d also rather not carry too much of an excess. Hence, some calculation is needed.

Going to Jool, I eyeballed the Kerbin ejection burn, and ended up with way too low a solar apoapsis, spending lots of fuel to raise apoapsis in solar orbit. This time it won’t happen. I will make a tool to tell me exactly which speed I should have depending on altitude, so I plan to get a Duna intercept right. Should be 1100 m/s. Let’s make it 1200, for safety.

Of course, while I plan to pass near Duna, it would take a huge amount of luck to get an intercept. Instead, I will have two options. Option 1, do what I’ve been doing with Minmus: circularize orbit until I am slightly lower than Duna, or slightly higher, and overtake the planet. That is only practical if I miss the planet by a small amount. Option 2, I will do what I did in coming back from Jool, taking the exact time of passage and using that to calculate how to modify my orbit to meet Duna in the next passage. The encounter must be at the next Duna orbit, at the latest, because of the radiation deadline.

Both options require circularizing in solar orbit. I checked, it’s 950 m/s. Let’s make it 1 km/s. On the plus side, arriving at Duna I will have a very low intercept speed, so I can mostly neglect that cost. Let’s call it 2500 m/s to get there.

In the return trip, I will have to do the same, on the opposite direction. So, in total, I want 5 km/s.

Drop tanks can be modeled as fuel. After all, they get ejected from the spaceship during engine operation. A 5 ton drop tank can be modeled as having 5 tons of fuel that will be burned with Isp 355 s, and 665 kg of metal that will be “burned” with Isp 0. In total, I can consider the whole mass of drop tanks as fuel with Isp 310 s.

Paleodiastimoploio, after removing the fuel tanks I already sent, weights 55 tons. Applying the rocket equation, 5000=3000*ln(Mw/55), I get Mw= 275 tons. I’d have to launch 40 drop tanks. Ok, less than the 80 I used for Navis Sideralis Neanderthalensis, but it took me weeks for that one; I’d rather not repeat the full experience. Let’s try some less precautionary estimates, taking into account that I will shed a lot of mass on Duna.

The 55 tons of mass of Paleodiastimoploio are divided as such:

5.5 tons Cheetah engines

3.8 tons Poodle engines

7 tons drop tanks for the rover

3.5 tons for the Hamburger rover

4 tons for the disposable science kits

1 ton of spare kits for the rover

1.7 tons of spare kits for the reentry vehicles

1.5 tons of fuel for the service probes

3 tons of fuel, mostly in the sunshield. I will count that as dry mass and save it for emergency.

2 tons of food and water

2 tons for the command module

3.3 tons for each Hab module

The remaining 10 tons are mostly the reentry vehicles, the sunshield, and the service modules. I’m not counting them because I absolutely cannot afford to drop them.

I expect to have expended at least a couple Cheetah once at Duna, so let’s count 2 tons shed. I may be able to leave without the Poodles, but it may be more efficient to perform the Duna eject burn with them; I can certainly drop them for the last burn, which will be in solar orbit. Let’s average that to 2 more tons shed, it’s 4 so far. The drop tanks for the rover will be spent, and if they are not, they are extra fuel I can use. The disposable science kits also will not be there for the return trip. I may want to bring the rover back for a museum if I have extra fuel, but I can safely discard it, and its spare kits. It’s 19.5 tons shed with that. The fuel for the service probes, either I will have used it, or I will be able to recycle it. And I will have eaten 1 ton of food.

All in all, I can assume 30 tons of mass that will need to return from Duna. In an emergency, I can drop the command module and pilot Paleodiastimoploio from the Service Probes (I keep referring also to reentry vehicles, but the two are the same), and drop a habitation module too. I could even drop two habitation modules if I was really desperate. That would remove another 8 tons; in addition with the 2 tons of fuel in the sunshield, it can already be considered a very safe margin.

So, with 30 tons of dry mass at Duna, needing 2.5 km/s to return, 2500=3000*ln(Mw/30), I will need 40 tons of drop tanks. Before that, I will need another 2500 m/s to carry to Duna 55 tons + 40 of drop tanks, 2500=3000*ln(Mw/95), I get Mw= 217 tons, requiring 160 tons of drop tanks.

It means 30 drop tanks. Ok, factoring in the exact mass of the empty tanks and docking ports, I will need 28 tanks, but I prefer a nice round number. It will take a couple weeks (it took three, but only because I was busy), but it’s already a lot better than 40. Which is itself a lot better than 80.

8.2) Tanks for the tank throne

Spoiler

I start work on docking 30 drop tanks in the two lines

32! Kerbalism does cause the occasional malfunction

No, still 30. I freely admit I just reverted flight for those couple rockets that malfunctioned. Docking all the fuel tanks on the launchpad is a chore, I saw no point in repeating it

As I launch yet more fuel tanks, I gradually discover some quality of life ehnancements. For start, I discover that I can use 2x time warp while driving the rover. No, it’s not obvious; sometimes time warp destroys stuff moving on the ground. I also optimize the rover trail: I used to turn right near the spaceplane hangar and taking the crawlerway, but near the end there is a terrain glitch very dangerous to wheels. Now instead I keep going past the SPH, and I go down afterwards. I discovered that those ramps are not dangerous if taken diagonally.

Like this

Paleodiastimoploio keeps exploding, though

That's a rather annoying fixture. Sometimes it explodes, sometimes it doesn't. Sometimes it starts shaking, but if I quickly time warp, it stops. If Paleodiastimoploio doesn't explode within the first minute, it's generally safe, which makes me think it will work during the mission.

However, to avoid having this issue at every docking, I soon decide to create a train of fuel tanks in orbit, and then send the train to dock Paleodiastimoploio at once. This way, I won't have to load Paleodiastimoploio every time. Not only avoids the risk of RUDs, but the ship is complex enough that it takes some time to load and lags the game noticeably - though nowhere near my major ships.

I start docking the first two fuel tanks

Earlier in this project I built bigger drop tanks, which I now call the superheavy configuration (I can’t always get creative). In the previous nanodiamond run, I used the smaller heavy configuration. It turns out, the heavy boosters are adequate to carry drop tanks in orbit with some extra, and they are a lot safer to drive as rover – the superheavy has a relatively high chance of exploding upon activating the decouplers, or capsizing the rover if you fail a turn, or breaking wheels if you hit a ridge too hard, or capsizing the rocket once docked. I reserve the superheavy boosters only for the most challenging payloads – the ones where I need some aerodynamic-unfriendly modifications.

Like, the drop tanks only have a small battery, because they are supposed to be docked within a few orbits; to create a train with them, I had to place solar panels and antennas on a few of those launchers. And since the launcher is already very tight at 30 parts, I had to make room for the additional stuff by removing non-essential parts.

Like the nose cone.

For those, I used the superheavy boosters. The heavy was enough for everything else.

More drop tanks are added

I'm keeping the last part of the launcher for two practical reasons: first, those contains still a bit of fuel, which will be needed for the final docking to Paleodiastimoploio. Second, they also contain the reaction wheels needed to turn around the ensemble. At some point, after realizing all those probe cores are draining an ungodly amount of electricity, I decided to deorbit some of the more spent launchers, but I immediately regretted it due to how sluggish the tank train became.

Eventually, it grew to 22 tanks

I already placed 8 tanks on Paleodiastimoploio before deciding on this course, so this is the end.

The tank train has become quite hard to manage. Despite autostruts, the tanks wobble. The attitude control is very sluggish (damn square cube law increasing the torque more than the reaction wheels), and the wobbling means it's hard to point at anything precisely in any case. It will be a problem for docking, but Paleodiastimoploio can still turn around easily. Maneuvering with the engine works well enough, at least.

I had the tank train parked in an orbit 3 to 5 km lower than Paleodiastimoploio. This way it wouldn't have risked a collision, but it would have been cheap and easy to rendez-vous.

By lucky coincidence, as the final drop tank is docked, Paleodiastimoploio is passing close

The tank train maneuvers to reach the spaceship. It ended up at 152 tons and 260 parts

By the way, did I discuss docking without maneuver nodes and close approach marker?

Get in orbit. Fix inclination, by eyeballing - it won't be perfect, but will be within a few km. Get in an orbit slightly higher or lower than your target, to slowly gain or lose ground. Slowly is the key word here, else you may just miss it entirely. You should be able to get within a few kilometers. When you reach under 7 km of separation, point towards the target on the navball, and get a speed of 35 m/s towards it. That's enough to overcome orbital drift. Less speed is dangerous, you risk drif moving you too much, and you'll end up needing another burn towards your target, spending more fuel than you saved. It's probably possible to get into even closer orbits, but kinda hard, because the game does not show apoapsis and periapsis of your target. Anyway, with around 100 m/s, and a dozen rocket ignitions, you can perform all the docking.

The first time it was loaded in physical range, Paleodiastimoploio greeted me by exploding. Obviously

As anticipated, docking was hard, but made possible by Paleodiastimoploio itself being able to move with precision, thanks to Jeb

I also need to rotate the tanks correctly, else they'll interfere with the engines exhaust

After docking, I leave behind 15 tanks and detach the other 15 to dock on the other port

Lining them up wasn't easy, Paleodiastimoploio is a lot less mobile with the first tank line installed

But it was accomplished. The engine broke at the last ignition

Finally it's time to remove what's left of the launchers; they make up 150 parts and 35 tons, quite a lot!

Using a functioning engine to deorbit the broken one

Various launchers dropping in the atmosphere

This operation was slowed down by a glitch. When you deorbit burn a spent launcher, it will move out of physical range. But when you change vessel with [], and I know of no other ways to change vessel, you will still change to the spent launcher, even if it's outside of physical range. It's like the game included it among the vessels you can cycle with [], and doesn't remove it when it gets out of range.

Problem is, every time this happens, Paleodiastimoploio itself goes out of physical range. It takes a minute or two to load it again - and the time increases with subsequent loading, to the point that after a few times it's better to reload the game.

The drop tank train took a second to load. It seems the processes of the life support and chemical plants are what slows down the pc. Unfortunately, asking the crew to please stop breathing is not a viable solution.

Wait, it's actually a very viable solution, I'd just have to deinstall kerbalism. Except that the whole point of this career was to use kerbalism.

Anyway, Paleodiastimoploio is ready

I considered changing the name to Mesodiastimoploio, since it's a more advanced version. But if I did, I'd have to eventually reach Neodiastimoploio, and I can't have a name proclaiming "new" in a caveman career.

I did a preliminary test, and the engines work At TWR 0.28, the 1100 m/s burn will require six minutes; not good, but manageable. I still need to bring Jeb back on the ground, to avoid him getting irradiated too early, and then I will move on the crew at the final moment.

Oh, and I still have to figure out a few formulas on my datasheet for the ejection burn.

I can't wait to try and see how well Paleodiastimoploio works.

August 17

Sometimes they do, but every time i used those panels, i had to fix their positions individually afterwards. Just use the rotate tool.

August 14

On 8/12/2024 at 2:51 PM, Tecorian said:

Besides the high vertical speed, also your horizontal speed is too high.

Try to slow down below 30 m/s, even better less than 20 m/s, maybe you need to mount speedbrakes to reduce the speed and/or increase the wing surface for better gliding capability.

3-point fighter landing may work in real life, not in KSP1

50 m/s is generally fine as horizontal speed for landing. it's harder to make a plane that can fly slower than that.

though all my experience comes from using higher tech, sturdier landing gear. maybe low tech planes are more limited

August 12

you hit the ground too hard. the altimeter indicates 10 m/s of vertical speed, that's too much for most parts. you also weren't even with the ground

August 8

to be specific, I only use vernors on fuel tankers.

normal ships are too small to justify the extra mass, and they don't really need rcs anyway.

larger motherships don't need rcs, it's other ships that move around them.

but a dedicated fuel tanker, in the 100-500 tons range, is big enough that reaction wheels aren't all that comfortable to use, and it has to dock lots of times. they are the only case when spending half a ton for easier docking feels justified.

August 7

2 hours ago, not enough fuel said:

when i'm making this ship i don't understand why i wouldn't just put vernor engines on it for translation rather than monoprop engines, because that would require me to take up extra space with monopropellant tanks. so why aren't all RCS thrusters done with vernor engines? (assuming the ship uses liq/ox fuel)

vernor engines are practical on large ships. but they weight 80 kg each. even just having one for each of the six directions requires 480 kg of extra mass.

so, if you build motherships in the hundreds or thousands of tons, vernor is the way to go. for smaller crafts, using something lighter is better. and the small amount of monoprop held by most crew pods is enough, no need for extra tanks

August 7

23 hours ago, Señor Kerbal said:

He’s a smart kid (11) and wants to learn, but he has resisted doing any of the tutorials and when I try to teach him anything, he gets up and leaves

that's a huge attitude issue.

he wants to learn, but he doesn't want to do anything to actually learn. it's like declaring that you want to get fit, but don't want to go on a diet or go to the gym. maybe one day we'll get magic pills for it, but right now, if you want results you have to put effort.

it is possible you are a bad teacher and he doesn't get the way you explain. but then he should do the tutorials.

maybe you could tell him, with a kind but firm tone, that he has to learn somehow, and ask him what he is actually willing to do in order to learn. explain him that while he can learn by doing, he needs some basics first. and conclude by remarking that if he's not willing to put in some patience to listen, then he doesn't actually want to learn after all. though pretty much anything worthwile in life requires effort.

those are life lessons that extend far beyond this game.

August 6

Part 7: Preparing for Duna

Going to Duna requires a lot more preparation. Besides, it also requires a dedicated lander. Paleodiastimoploio is expanded to take care of those needs.

Paleodiastimoploio now has everything it needs, except the fuel tanks

7.1) Harnessing some sled dogs

Spoiler

As I established in the previous chapter, I need more thrust to avoid multiple passages in the radiation belts. For this, I will bind two Poodle engines to the back of the sunshield. There's a small problem with that, there is no docking port where I need; hence I will send Bill in a spacewalk to install a couple of docking ports. To send him up outside of a cockpit, I will once more resort to a tried and true designed I developed for my previous caveman.

Bill goes out of the cockpit. Jumps on the truss

Grabs a ladder, goes into the cargo bay

The truss is jettisoned, and the ship goes to space on remote piloting. Now, for weird reasons, Bill is not shielded from the airflow, even though he's in a cargo bay. He generates a ludicrous drag. The lone astronaut creates more drag than the whole rest of the spaceship. To compensate that, the shuttle has a lot of extra deltaV.

Quite a common situation in a caveman run, really.

The only real difference introduced by kerbalism is that Bill has oxygen for two hours. That's enough to complete the mission with a reasonable margin, especially if I can spend deltaV to force an earlier encounter.

Bill installs the docking ports where needed, then gets inside his ship and returns

Now that the ports are in place, I send the engines. They are drag incarnate.

I launch them with extra deltaV, courtesy of the drop tanks rover

Sigh. The whole "this payload has terrible aerodynamics, so I send it up vertically with extra deltaV" is starting to get stale. Ok, how about this: to avoid the rocket flipping, I put the draggy payload at the bottom, and the main rocket body on top. To have the poodles as close to the rear as possible, I put even the second stage engine in front.

Like this

The rocket reverts in mid-flight after jettisoning the first stage. That's a novel solution

The Poodles are docked to Paleodiastimoploio

I considered unlocking fairings. If I landed on all remaining Mun biomes that I partially explored with unmanned probes, I could just get one more tech. But it would be a lot of work, adding drop tanks is faster.

7.2) Bits and odds

Spoiler

Following a bunch of smaller parts that don't deserve their own chapter.

The command module, on the launchpad

I want a dedicated crew cabin for a pilot to command the ship, and a probe core to at least keep stability in any case. Not strictly needed, I could have used any of the other command modules I'm about to send. But I like it. And it's habitale space. I wanted a two-seater, and the Mk2 Command Pod is better than the Pea pod. I needed to get the advanced flight control tech for the Mk1 Lander Can anyway.

Speaking of habitable space, I added a third Hitchhicker container. No pictures for it. This time, I managed to stick 4 docking ports to it without blocking the exit hatches by the incredibly complex trick of staggering them 45°. I don't know why I didn't think of it earlier.

Escape pods and service probes

Another thing I established I would need is some sort of reentry pod, so that the crew wouldn't have to aerobrake gradually, passing through the radiation belts every time. Well, I could have added 900 m/s of fuel instead, but two pods are lighter. In the picture above, shown as they jettison the first stage.

I am incredibly frustrated with how draggy those round command modules are. It's ridiculous. A sphere is decently aerodynamic, but those things are worse than a flat surface. I swear, a Hitchhicker causes less issues! They also have ridiculous surface, which is irrelevant in the stock game but requires more radiation shielding in kerbalism - the mass of the additional shielding more than makes up for any mass saving.

But hey, those things have good heat tolerance, so I need them as reentry vehicles.

Since they are there, they can also double as Service Probe(s). I won't have communication, so a service probe that must move stuff around needs a pilot. Those Pea pods need a bit of fuel and small engines for final course corrections, I may as well put them to use. The Ant engines are wonderful for the purpose of orbital maneuvering, they have more than 100 allowed ignitions.

And of course, the Service Probes need some small dedicated fuel tanks, for practicity. Any fuel not used will still be good for the main engines

Fuel tanks are placed. Also, there were no other screenshots showing how the command module and Service Probes are placed

Next item on the list is science. Materials bay and goo canisters can't be restored in caveman, so they will be discarded after use. Again, I recycled the design I had for Navis Sideralis Neanderthalensis.

The science stuff, going orbital

That payload has an even worse aerodynamics than most of the other horribly draggy stuff I'm launching, but it's also light. The first rocket I sent flipped three times, but there was enough fuel to still reach orbit.

I sent a total of 12 science containers. I plan to send a rover and scout some additional biomes, just because a normal lander feels uninspired.

The science containers are docked with Paleodiastimoploio

Since I'm there, I also used the leftover fuel in the second stage to deorbit some space debris. I was leaving too much litter in the low orbit

Now it's time for some redundancy. Paleodiastimoploio already has exaggeratedly high standards in that regard, but its landers and probes don't. What if one of the reentry pods breaks the reaction wheels? Or a parachute?

Four service kits are added to the ship

Those kits are lightweight, and contain everything a vehicle needs: reaction wheels, life support, parachutes, food. Just dock and take one. I may have issues with the docking if a vehicle breaks its reaction wheel; but then, I have two Service Probes for one such occasion.

All the stuff I'm docking is starting to confuse the game. Occasionally, Paleodiastimoploio will start shacking. If I'm not fast to time warp (which cancels relative movement within the same ship) it will break apart.

Quite spectacularly, at that

Well, this is a nanodiamond run, but for that specific problem I consider myself fully allowed to reload.

I tried fiddling with autostruts - or their lack thereof - but couldn't find any conclusive solution. At the time of this writing, I seem to have stabilized the structure by splitting that pile of 8 science containers - they seem especially bad. But I have no certainty that Paleodiastimoploio won't disassemble again the next time I load it; for safety, I now save the game before getting the mothership in physical range.

Next item on the list: more food and water.

I could send multiple smaller containers in a more linear fashion, but this reduces part count

Radiation will kill the crew in four years and a half. No point bringing food for a longer duration. Including the smaller containers with the service kits, I loaded food for five and a half years, which will cover possible "food has been dumped overboard" issues.

Finally, I need some more Cheetah main engines.

Delivered as a neat pile that can be docked to the sunshield when the main engine pile there gets exhausted

That should cover all I need for travel and reentry. Now it's time to design the rover.

7.3) A rover for the red planet

Spoiler

As I mentioned, a simple rocket lander seemed lame, so I decided to make a full rover.

A rover will need solar panels, a fuel cell to survive the night, science instruments, and of course full redundancy. I even included the Geiger counter, I will finish the challenge with the science I return from Duna, so it's no longer cheating. I tried to go for a large crew, but in the end just building a rover for a single person proved difficult enough with the limitations of kerbalism and caveman together.

The rover, as it should be. The docking ports will dock fuel tanks

Of course, that thing has 50 parts, and there's not even a launcher yet. So I stripped everything I could from the basic design - basically, I only left what could not be added with EVA construction.

A stripped-to-the-bone Duna rover, ready for the launchpad

And now Bill has to work on adding everything else. Getting the wheels properly lined up was a pain. And then I discovered I could not install the engines inside the trusses in EVA construction, so I had to remake the rover and start again.

To provide better access to the top, I have a new version of the Brontosaur rover

Four kerbals are required to lift an Oscar-B fuel tank. Good thing I have exactly four

After the rover is completed, drop tanks are added. Here I realize the wheels block access to the docking ports, except two of them. So I have to revise the design of the drop tanks a bit, by sticking them to each other.

Like this

All those tanks may be overkill for a 3.5 tons payload, but I can't test this thing, I want to be sure it can reach a stable orbit on the first try.

Wait, I forgot to name the rover. I can't keep writing "the rover" in the report. I stitched it up together, like a Frankenstein monster, maybe I could merge it with the name of an actual rover and go with Frankensteverance? Naah, I don't like that sound. It's X shaped, maybe X Without Wings? But I stopped liking Star Wars decades ago. And I already used the X shape as inspiration for a name in Right Answer, for one of my Jool 5. It's short and squat and sort of round, and it will be even rounder with the addition of drop tanks. It really looks like something that has been squashed flat. So perhaps Hamburger? I like the sound. It keeps with the tradition of naming small landers after mundane objects. Hamburger it is, then.

The rover was very difficult to control. But the bloated first stage was enough to push it past the low atmosphere

I realize just now that I had no contingency plan in case the launch failed. Which normally is cool, but this time I had Jeb piloting - I figured I could use all the attitude control I could get. I dodged a bullet here. Sure, I could lose Bill and hire another pilot and move on, but it's not the same thing.

Hamburger in its final shape, approaching Paleodiastimoploio

And docking on the front

7.4) Moar bits and odds!

Spoiler

Hamburger can land on both Duna and Ike, but it still needs its fuel tanks. Four 1-ton tanks give 2000 m/s. Some will be spent to soften the landing; then there may be some service kit added to the rover, making it heavier. And I totally sacrificed aerodynamics, to the point that even Duna's atmosphere is a serious obstacle. In the face of that, I would not want anything less.

Ike is a lot easier, two drop tanks providing little over 1 km/s will be enough. I can even loan one of the smaller drop tanks for the Service Probes, if needed. So, I will launch six 1-ton drop tanks.

In two batches of three, here the docking of the second batch

I moved them around for better balance, including docking two of them to Hamburger already.

Finally, Hamburger has unique needs: to last the night, it has fuel cells, and electrolysis apparatus to make hydrogen during the day. What if some of that breaks up? The service kits don't have fuel cells. So I'm sending a couple such kits tailored to Hamburger.

Here shown with the second stage

Only one of them has parachutes, for Duna. If that one breaks, I will add one of the regular service kits, of which I have 4.

And that's all, I'm ready for Duna! Now I only have to carry enough fuel.

Paleodiastimoploio, status

In the end, this thing is heavier than I was hoping. Then again, I already docked a 5-ton fuel canister, and the two fuel connectors hold another 5 tons by themselves. Plus the sunshield is holding another couple tons. Anyway, I have to bring all that stuff to Duna and back, in four years, without maneuver nodes. I made some detailed calculations of how much fuel I will need, but I'll spare those for the next chapter, which would otherwise be very short as "I sent up the same fuel tank a few dozen times, now I'm done, yay!"

August 4

it says propellant requirements not met. maybe some part is blocking fuel transfer

August 1

On 5/29/2024 at 11:02 AM, Ianwubby said:

Also I think probably scratch what I mentioned about my Eve ideas; I was wondering if I could glitch a propeller boat underground using bendy-tech timewarp shenanigans, and do a completely aquatic eve circumnavigation instead of doing part of the trip on land.

On 5/29/2024 at 2:57 PM, damerell said:

I'm going to have to nip this one in the bud and say that this is definitely not permitted. Sorry.

Fun fact, you can perform at least part of a circumnavigation on eve underground without using any time warp sheanigans. the terrain glitch at the south pole has an entrance

i went in and drive around a few minutes. i don't know if the north pole has a similar entrance to go out, though

July 31

Part 6: Paleodiastimoploio's maiden voyage

Paleodiastimoploio goes to bring a crew to Minmus, then take a dip in solar space. Besides colllecting some science, the mission serves as a general test for the future Duna mission. No major issues are found, though a few things can be improved.

6.1) To Minmus

Spoiler

Paleodiastimoploio weights 50 tons, and the Cheetah engine provides 125 KN of thrust, for a TWR of 0.25. Too little to make the Minmus transfer burn in one go, especially without maneuver nodes. I have to perform a couple consecutive apoapsis raising.

A close-up of the ship

Radiation report

Unfortunately, a gradual apoapsis raising entails crossing the radiation belts. Here I'm only getting a few % of radiation, but with the crew subject to continuous low levels through all the trip, I will want to avoid it when going to Duna. So, first issue found: provide more thrust.

Jettisoning the first drop tanks

I made a perfect Minmus transfer, but I forgot the plane change maneuver. Oooops!

I can fix that. Circularize, make sure to cross Minmus orbit

Now Minmus is further ahead than Paleodiastimoploio, so if I enter in a 45x45 Mm orbit I will catch up. Ultimately, I'm glad for the accident; it gives me the chance to test longer term survivability in terms of supplies, stress and radiation exposure.

Solar storm. Note how radiation is 4.7 rad/h, while habitat radiation is 7.3 mrad/h

This shows the sunshield doing its job. The solar storm is completely negated. I was unsure it would work so well, since there are small holes between the fuel tanks. The 7.3 mrad/h can't be avoided, they are the background radiation lowered by the shielding (which at the highest difficulty level negates only 72% of incoming radiations). Without access to decontamination units or active shields, the crew has a hard time limit for how long it can stay in space. Which is why I want to reduce as much as possible time spent in the radiation bands.

Note that by past experience, the game glitches if warp speed is greater than x1000 during a storm, the crew gets slightly irradiated. I don't want to check if the bug is still active; I also would rather not slow down the game dozens of times, I think I'll just lower solar storm frequency. Solar storms are potentially a huge issue, but once you have a safe way of dealing with them, they are no more than a waste of time..

6.2) At Minmus

Spoiler

Without other issues, Paleodiastimoploio arrives at Minmus. There, it drops an unnamed lander.

The lander carries two people at once. I want to bring everyone on the surface, to promote everyone to level 3

The lander arrives on the surface with minimal fuel spending

Those low thrust engines are quite dangerous, my instinct is to come down with higher speed, but here I must brake in advance.

Since fuel is limited, I reach some biomes by rolling on the ground

Slow, but effective for short distances.

Coming back for the second fuel tank

Here I had an issue. Without the lander, Paleodiastimoploio has no control - I plan to add a dedicated pod, later, but I didn't think it would have been relevant. Anyway, while the solar storm raged, I was unable to orient the sunshield properly, and the crew took damage. Also the crew in the lander took damage. I will need to devise something for the Ike landing, Ike is exposed to solar storms.

I still had to grab science from greater flats. But I placed the components in the wrong order to discard the spent science bay. Here improvising

Docking the science container on the ground. Not the most elegant solution, but I could drop that dead weight before going orbital

Fuel was a bit short, I almost lost the lander. I should have carried more fuel; barring that, I should have skipped one biome, it's not like the 2.5 science I get from crew report is all that important.

I also ended up with limited resources in the lander. Just like I can't transfer fuel between tanks, I also can't transfer food and oxygen. In this light, using electrolysis to replenish oxyge stocks everywhere is good. But I will need to provide small supply packages that probes will be able to grab, in case they run out of their own.

6.3) In solar orbit

Spoiler

Now I will leave Kerbin SoI for a short time, to grab some additional science and provide enough xp for the crew to advance to level 3.

Leaving Minmus. Still half a drop tank available, then I can drain the connectors, then I have some emergency fuel in the sunshield

Orbiting Kerbol

Unfortunately, I came out on the wrong side, orbiting lower and ahead of Kerbin. Hard to aim, without maneuvers. So, this orbit will bring me farther and farther from Kerbin. I need to spend some fuel to rectify that issue.

Burning towards Kerbin

So, just like I did in the previous caveman, I pointed the ship towards the planet... no. No, I wasn't so crass. I did learn a bit since then.

I have an orbit slightly inside Kerbin, meaning I'll move a bit faster. I could raise orbit, ensuring I move slower, and this way I will surely meet Kerbin. But it will take at least 6 months. Barring that, I could burn radial-out, until Paleodiastimoploio is moving away from Kerbol. I'll do that. Notice how pointing radial-out in the navball is the same as pointing towards Kerbin. But at least I know when to stop burning: when the altimeter says I am no longer moving downwards.

It required some 300 m/s. I ended up consuming what's left of the drop tanks, and one connector. I set the connectors to be drained separately, even though it imbalance the ship, because that way I don't have to launch both connectors again.

To circularize, I use aerobraking in high atmosphere. Paleodiastimoploio is not made for heat endurance, so I am keeping a 60 km periapsis. Still, the sunshield is great at aerobraking

As I take several passages through the atmosphere, I am also spending more time in the radiation belts. I would be a real joke to return from Duna, only to lose the crew during circularization maneuvers. So I will include a couple of hardened reentry pods that can bring the crew on the ground with minimal radiation exposure.

The first engine lasted more than it should have, but eventually it broke from repeated use. Here's why I carried 3

And with that, Paleodiastimoploio circularized back into a 90x90 orbit.

The maiden voyage was successful. Radiation levels were as predicted. Water consumption was minimal. Crew stress was under control. Structural stability was good. Ship performance and maneuverability was good.

The mission also highlighted a few issues. I have to increase thrust, to avoid passing the crew through the radiation belts multiple times during the transfer burn. I have to include heat-hardened reentry pods, to avoid passing the crew through the radiation belts multiple times when returning. I have to make sure that the Ike lander will be radiation-hardened. I will need to prepare some food supplies that crew pods will be able to access.

Now I have to refurbish the ship and ready it for Duna.

July 29

Part 5: A new mothership is complete

Paleodiastimoploio is completed, at least the parts necessary for a Minmus mission.

Paleodiastimoploio full status. Oxygen is low because I'll need to make more from water

5.1) Minmus lander

Spoiler

I want to land a crew on all nine biomes on Minmus, that requires some fuel supplies.

The first rocket I sent broke the engine. It's high enough to use the second stage, by sacrificing the fuel I managed to bring the science to Paleodiastimoploio. Only to discover I lacked the proper docking port on it

The lander itself. Four Ant engines, a simple setup. It will grab fuel tanks as needed

Those round pods are a huge aerodynamic hassle, but I need them because they are pressurized. Docking the Mk1 pod will cause the whole ship to become unpressurized, and that will wreck crew morale. The crew, in turn, will wreck the mothership in stress-induced breakdowns. Better to suffer through some difficult ascents. Even better would be to use a fairing, but I have none.

After I had everything complete, I realized I forgot radiation shielding. Not strictly needed for this mission, but I want to test its effectiveness, so I sent up a replacement.

The replacement also includes science instruments, which I had to place with EVA construction due to part limits, and the last two crew members. The parachutes are only in case of flight failure

5.2) Fuel tanks

Spoiler

For the fuel tanks, I am also keeping the design I devised for Navis Sideralis Neanderthalensis. No point reinventing the wheel.

Upon loading them, I saw they require the Cheetah engine, which I don't have. I briefly consider cobbling up a new system, but I quickly discard the idea. Sure, I could, but I already launched 80 of those fuel tanks, devising a most efficient and reliable launch platform. It's probably the single most optimized vehicle I ever made, I never launched anything else so many times. So, there is value in using it. I drop another couple of Mun landings and unlock heavy rocketry, then I get a test contract for the Cheetah.

That took forever, by the way. I cycled through hundreds of contracts before getting the cheetah. I keep getting test contracts for the Bobcat or the Twin Boar, but Cheetah appears to be very rare.

During those Mun landings, I found this weird graphic glitch

I tried, but the sun through the hole in the ground does not recharge the solar panels

I also almost collided with the mountains next to the canyon. I underestimated how high they were, or how low I was. I almost lost Jeb

Entering inside Kerbin in map mode I got this view. The color palette is magnificent

Before the stackable drop tanks, I need the connectors. I left the holes in the sunshield for them.

That docking port is on the wrong side. I'd need the Service Probe to fix this, but I didn't include one. I will need to repeat the launch

I didn't include the Service Probe because I want to send one that works on Duna too. I don't have antennas that work from Duna, so I need the probe to be manned, and for that I want the Mk1 lander can, which I will unlock with the technology I'll get from this trip. I still can squeeze more science from Mun if needed; I just landed on the last biome, but a good half of the bomes were landed in the early game, with the probe lander lacking materials bay. In some of those biomes that early lander failed to launch (see subchapter 2.1) so I only got very few science from them.

But I didn't take pictures with the correct connectors, so I have to post what I have.

I also have to send up the engine block.

The engine block being docked behind the sunshield

The engine block is made of three Cheetah engines stacked on each other, to provide redundancy in case of malfunctions. For some reason, despite being neatly stacked, they caused terrible drag. But they were light enough, I was able to carry on a vertical launch with four drop tanks added to the main rocket.

Now, finally, the main fuel tanks.

Launching the 5 tons fuel tanks requires the use of six drop tanks, two of them with a Flea boosterfor higer TWR at launch

In this setup, the launcher weights 37 tons, over twice what would normally be allowed by the level 1 launchpad. I made the drop tanks slightly bigger, which gives an extra 100 m/s for the docking. Those bigger tanks increase the chance that the rocket will capsize on the launchpad. I need to dock both flea boosters on the sides before I can start the individual tanks.

The flea boosters are dropped early on, but they provided much-needed early acceleration

Second drop tanks dropped

When the final set of drop tanks are dropped, the rocket is already in the high atmosphere

It runs out of fuel for the first stage soon after; the Cheetah takes over. It's got low TWR at the beginning

The rocket drops tanks from the tip, just when it's high enough to no longer need a nose cone

A second drop tank is discarded from the tip just before achieving orbit

The fuel tank approached Paleodiastimoploio. It's got a small Ant engine in the cargo bay to help with docking

Docking. This better shows the shape of the sunshield

Finally, the engine is jettisoned and deorbited, leaving the fuel tank neatly docked to the growing ship

That's an extremely efficient system, the staging is very well placed. I'm especially appreciating that I devised a system that doesn't leave orbital debris. I wasn't as careful in this career, and I littered the low orbit with pieces of spent Mun landers.

Navis Sideralis Neanderthalensis required 80 fuel tanks, but for my purposes four will be enough. I want to reach Minmus and then take a dip outside of Kerbin's SoI; 2 km/s should suffice, I'm carrying over 3, and that's without counting the emergency fuel in the sunshield.

Finally, some food, water and nitrogen. This launcher was aerodynamically challenged, but light enough to allow a fully vertical launch

Last I sent up the crew, but I already included them earlier in the Minmus lander subchapter.

Paleodiastimoploio is ready for its maiden voyage

Life support looks good; that single large container gives food for two and a half years. Water supposedly will last less, but it will be recycled. Oxygen will be produced from water by electrolysis. Two small nitrogen cans will last 25 years. I'm so used to my colossal mothership, I sometimes forget how little it can take...

Main issues will be stress and radiations, though. Besides grabbing some science and leveling the crew to level 3, this mission will provide some hard data on the resilience of the system.

July 27

there was another guy a few months ago who had the same problem, it turned out it was just a bug. you tried reloading? restarting the game?

July 26

Part 4: A new mothership takes shape

Looking forward to a Duna mission, I start building the required mothership: the Paleodiastimoploio.

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Here docking the sunshield, to protect against solar storms

4.1) Habitation modules

Spoiler

I mentioned earlier I wanted to first send kerbals to Minmus. Going to Minmus will be a longer term mission, it could take upwards to a month if I miss the intercept. I want to provide my crew with some comfort for a longer mission, and this will provide an ideal testing ground for the final Duna mission.

I run some more Mun landings, until I unlock Space Exploration. It gives me the Hitchhicker Container, to store my crew in relative comfort for a longer time. Perhaps even more important, it unlocks wheels, which are required to install more drop tanks on my rockets and launch bigger payloads. I used that strategy extensively during my previous caveman run, and I developed several well-optimized vehicles for the task. I directly copied those crafts in this career, they worked very well.

Before setting to work, I need a name. A name that fits with caveman. Navis Sideralis Neanderthalensis was excellent, but I already used it. Let's go with something along the lines of paleolithic? Paleolithic means ancient stone [age], let's go with something like ancient spaceship. Ask google translate how to say spaceship in greek... huh. Diastimoploio. The new mothership will then be dubbed Paleodiastimoploio. Hard to write, but I like it.

Then I contacted a friend with linguistic studies to ask how the hell greek is a indoeuropean language if their words don't look anything like ours. Ancient spaceship = paleodiastimoploio. Was an interesting conversation, but I'm going on a tangent here.

The runway-launched tanker rover docks additional fuel tanks to the rocket, allowing to overcome the 18 tons limitation

Sometimes the tanker doesn't work as intended, but you can always send another

The launch system thus assembled sends the first habitation module

The Hitchhiker Container provides 9 cubic meters of living space, it's got the best space/mass ratio among the parts I have available. It also provides the threadmill, increasing crew morale. I'm putting maximum radiation shielding, which adds another ton to the ship. Radiations will be the big issue in this mission, even with top shielding the crew will only last four and a half years. Alas, I don't have access to either the active shield, nor the radiation decontamination unit. But judging by the experience with Minmus, 4 years should be enough for Duna.

I'd like to send two containers at once, but they are a nightmare of drag. Even sending a single one in orbit is hard, with the parts and limitations of caveman.

Joining the first two hab modules

When going to Duna, I will want at least 4 hab modules. But for Minmus, two will suffice.

4.2) Chemical plants and other necessities

Spoiler

Without enhancements, the crew pods only have two functionalities. I reserved those for air scrubber and pressure control, but now I need external units for water recycler. I am also puttin in water electrolysis, because it's cheaper to carry oxygen as water than to carry oxygen tanks. The hydrogen obtained as byproduct can be used to recycle some waste CO₂ by the Sabatier process.

I am sticking all those chemical plants to a structural fuselage, because it had the best [surface to attach things]/mass ratio. I don't have any of the more fancy cargo bays. Then I also need some basic containers. The large stockpiles of food and water will be on a different launch, but - as I learned at high cost when A'Twin life support failed to work because it lacked a waste container - I need basic containers for intermediate products of the various life support cycles. A container for waste water, else waste water will be discarded instead of recycled. One for CO₂ and one for H₂, to store them temporarily before the Sabatier process can occur. One for oxygen, I'll produce it continuously but I need some temporary stockpile.

Since I'm here, I'm also putting antennas. They won't do anything at Duna, but they will still work past Minmus.

The resulting service module

Those service modules are fairly light, but they take up a lot of parts. And they have even worse aerodynamics than the Hitchhicker Containers. I need drop tanks not much because of the mass limit, but for the part limit.

But since the rocket is light, adding drop tanks unbalances it and causes it to fall

I solved this problem by leaving the tanker rover attached to the service module, to provide a larger base. So, the two drop tanks on the wide side of the Bobcat engine, those are fine. But for the other two drop tanks, I would dock one tank, leave the rover there, send another rover to dock the second tank, then undock both rovers.

Also due to part limitations, I could not afford a decoupler

I resorted to stacking the Terrier engine directly on top of the Bobcat. The Terrier is activated, overheats the Bobcat, causes it to explode. There, no need for a decoupler

I'm calling this solution "very hot staging".

Both service modules are docked. I needed multiple redundancies because I won't be able to run any kind of repair

This was a lot of effort to save a few tons of cargo. In retrospect, maybe I'd have been better off just carrying more water and oxygen and skipping any chemical process. But now that I sent them to orbit, I may as well use them.

4.3) Batteries

Spoiler

Another issue of Kerbalism is that the ship will consume electricity full time, even just for heating. Losing electricity will kill the crew. I considered putting in more fuel cells and hydrogen tanks, but decided to just send a bunch of battery packs. Slightly less efficient, but I won't have to worry about malfunctions. Batteries are light, anyway.

I like the Ant engine placed for easier docking

Both battery modules placed

Those were easy; light, without aerodynamic issues. I only had to send them separately because of part count. So far Paleodiastimoploio is 11.5 tons, but 97 parts.

4.4) Sunshield

Spoiler

Until now, I ignored radiations. But for a longer mission, they are a major problem. While past experience shows a simple water container may suffice as solar shield, I want something more reliable. Especially as Paleodiastimoploio will grow longer. So I build a dedicated sunshield. I could call it umbrella, but sunshield sounds cooler. The marketing department thought it would help justify the price tag.

The sunshield in all its glory

I used large flat fuel tanks because they were the best I had. I have unlocked the technology to build rocket engines, I have the technology to create orbital habitats that could support life for years, but I don't have the technology to build a square metal plate. That requires composites, a 300 science tech. I had no idea square metal plates were so hard to manufacture.

The sunshield will be exposed to the sun, so it's the best place to stick solar panels. Due to part count limitations, I had to install them on the launchpad

There, those should be enough to cover for malfunctions

I like how the sunshield looks silhouetted by the sun

I was really worried about drag flipping the rocket, hence I'm flying straight up (a common strategy for draggy modules). But while drag is high, the sunshield wasn't prone to flipping

Sunshield being made of fuel tanks, I don't have to worry about deltaV. The leftover fuel will be emergency fuel for Paleodiastimoploio

Sunshield installed

I cut out the sides instead of making a perfect hexagon to leave space for the drop tanks.

July 23

1 hour ago, r0teRakete said:

Yes, i checked but there is nothing listet like RDU.

In R&D in the moduls description the RDU is mentioned.

Bulding a ship, editing the PPD-10, configuring Sickbay Modules, my only option is TV or None. Can't find RDU anywhere.

The Mods iam using: ( kinda surprissed myselfe, how long the list has become )

Big Thanks in advance to anyone using thier Braintime on my problems <3 <3 <3

huh, then it's a bug. and i don't know how to fix it.
though i have to say, i found plenty of bugs in kerbalism - in my rss + kerbalism grand tour, i recorded 47, and i had a fraction of the mods you're using. So in the end, you just have to adapt.

I advise just adding solar panels or nuclear reactors until that -7 electricity no longer bothers you. Also check oxygen consumption, as the RDU also used that up. but it turns it into CO₂, which you can convert back to oxygen with a chemical plant. Your ship looks like it could dock an additional energy module without a significant impact on performance

by the way, what kind of tv are they using? it weights 50 kg and costs more than many early game mun missions!

July 23

40 minutes ago, r0teRakete said:

Hey Everybody!

I landed herer because i clicked the link in ckan next to kerbalism. I just ran in the same problem the second time.

Problem: Radiation Detox Unit is consuming lots of energy, though i think i don't have this Unit on my ship.

This first time i had this problem i was trying kerbalism in an old safe.

This time its a fresh savegame.

Is this a bug? Am i missing some thing?

hard to say, with everything in german. indeed, i do not see RDU. there are still a few potential explanations, though.

what you should do is check on "auto", in the upper right part of the screen. see from the picture, right now you're on info, go on auto, it showcases all processes on the ship. there you can see if there is some RDU you missed.

July 20

Part 3: I run out of "we choose to go to the moon" references

Putting a kerbal on Mun, obviously.

Final descent phase

Spoiler

The Minmus landings unlocked enough parts to try more complex missions. Next target is manned landings on Mun. Then it will be manned landings on Minmus, and then Duna.

In my previous caveman, I opted for a lander and a booster that would dock in orbit. That's time-consuming, and since I mastered the art of attaching extra drop tanks with a runway-launched rover (plus I have unlocked the bobcat engine with a test contract), I wanted to try that avenue, to keep the mission in a single launch. Alas, I was twarthed not by mass restriction, and not even by not having unlocked wheels (that could be fixed with a couple more Minmus landings). No, the big problem was part count.

In kerbalism, engines can break at any time, as I'm sure you are tired of hearing. While I was running orbital missions, I didn't worry; if a rocket was disabled by loss of engine, I could rescue the kerbal easily enough. While I did the first Mun flyby, I didn't worry too much. Sure, a malfunction would have resulted in killing Jeb, but I only needed to fly the mission twice, and only for a flyby, it was a very small risk.

Now I have to land, which entails many more ignitions, and I have to do it potentially up to 7 times. And I have the means, so there's no way I'm risking a kerbal's life every landing. So I want redundant engines.

First Mun lander project. I was trying to save parts by storing solar panels and some instruments in the inventory

30 parts are a fairly tight limit in any case. Now, instead of a single engine, I need 4 engines, and since those engines need some kind of node to stick, I also need 4 fuel tanks to attach the engines to. Eight parts, when in the past I could use a single engine.

Then I have to carry a gas tank and some food too. And of course I need to bring 5 science instruments, else what's the point of landing? And that leaves very little for the actual rocket.

I had to give up on the plan of a single launch, and go for two launches just to have enough parts. In fact, having the extra engines takes up so many parts, I had to put the science instruments in the booster.

The booster. It docks with the lander, providing an additional 1000 m/s of deltaV. And bringing science instruments, in this case

Onward to Mun

Engine broken

Funny enough, I lost two booster engines, and no engines on the lander, despite the lander engines being more and used more times. Ok, since the booster engine was used a few times and is not critical I didn't bother making it high quality, but still.

Anyway, since the booster is broken, the ship needs to return to Kerbin. I can at least test the reentry.

The rest of the ship exploded. I take it to mean that I really need the thermal shield

Besides the premature end, this lander wasn't adequate anyway. Those lateral tanks create huge drag, making me waste fuel; I probably wouldn't have enough for a Mun landing anyway. I need to fix that.

A key breakthrough came when I realized I didn't need the Spark, I could use 4 Ant engines.

Another experiment. Those baguette tanks look better, but this design is still too draggy

Now we're getting there

The final version has 8 Ant engines, though I could reduce them to 6 if really needed. Four of them are not visible because they are inside the decoupler; they cause a lot of drag, and I was trying to shield them. It didn't work, they still cause drag. Anyway, the rocket flies. I put a nose cone over the docking port, it's the wrong size but the game doesn't seem to care. I discovered that the docking port generates an insane amount of drag, as shown in the picture below.

An experiment to test drag reduction strategies

I built the rocket with normal decouplers, and I put a docking port inside the stack, that will get exposed once the upper part is detached. The above picture shows, the docking port still counts as exposed to the air, and it generates 40% of the total drag of the rocket. The engine causes another 40%. Ultimately, while tapering the rocket by stacking a size 1 tank over a size 0 decoupler, it's still the lesser evil.

On the plus side, since the docking port makes so much drag, I can skip the thermal shield decoupler. I can be sure the pod will never flip and reenter tip-first, so I just leave the thermal shield in the middle of the stack. The heat will melt the rocket, until it will find the thermal shield, no need to decouple anything.

Here the Mun lander is detaching the rocket and the nose cone

That lander can look like a wizard hat, so I'm calling it Wizard. The booster is long and sticklick, it can be the wizard's Staff.

Wizard docks with its booster. The annoying part is, without action groups I have to deactivate each Ant engine individually

A crew pod has food and air for 5 days. As I could spare a part, I decided to include an oxygen tank, but leave the food and water on the booster. The reason is, in case of delays, the kerbal can survive a few days without drinking, gaining that much time for a potential rescue. With the extra food in the Staff, life support is enough for 25 days - an exaggerated number, but I learned to be prodigal with life support. All those supplies only weight a few tens of kilograms.

Staff, having exhausted its fuel, is jettisoned. It leaves behind the science section

Wizard lands on Mun easily. I didn't miss landing legs too much

The experiments are recorded and stored in the storage unit, then the science instruments are dropped

A pity not recovering their money, but I have infinite money at this point, and the Science Jr will burn in the atmosphere anyway.

Leaving Mun, with the power of 8 Ants

Dropping gently on a parachute

The ship didn't even melt, I ended up not needing the thermal shield. After three such landings, I determined I could skip the thermal shield entirely after all. I used the freed part to add a second solar panel.

I considered small improvements, but they aren't really needed. Wizard and Staff are fully adequagte for their jobs, they entail no risks besides falling asleep during descent, and have a good amount of extra fuel.

Now I have to grind some biomes to get some final techs before I can send longer term crewed missions.

July 18

On 7/12/2024 at 8:16 PM, BarryAstroo said:

I made a colony with starships on duna but when i tried to refuel using surface harvesters and converters i realized that the rocket uses liquid methane. Is there anything i can do to get around this?

the fact that you have liquid methane means you have mods, and we can't help without knowing more details. why can'ìt you make liquid methane? what kind of stuff has your ship? too many unknowables

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