Sput42

Old Linux partitions? Linux is my main OS, and I intend to continue running KSP on Linux because that way I don't have to reboot for KSP fun...

Many people don't realize that real-world reentries are much steeper than you'd expect. They're also really hard; it's not like in stock KSP where you point your craft into the atmosphere and let it go down on its own. The atmosphere is not really going to slow you down above 70 km; it's just going to heat you up over time until you melt. If you look at the lunar-rated Apollo reentries, they aimed for a Pe around 40 km (some even lower). They go in very steeply and get slowed down at several gees. But since g-forces cannot be too high for the crew to survive, after the initial slow-down the capsule must go up again before it goes too deep. That's done by aerodynamic properties (because RCS won't cut it with the forces involved): capsules have an off-set center of mass (in KSP/RO, this is toggled by "Descent Mode" in the capsule's context menu). Rotation along the z axis shifts the CoM and thus changes the angle of attack, and subsequently aerodynamic lift changes the descent angle. So once the g-forces reach a tolerable maximum (around 60 km or so in the initial descent), the capsule rotates such that it starts going up again -- but not too far, because you also don't want to slip out of the atmosphere again! In KSP/RSS/RO, you generally want to keep it in between 60 and 80 km until you are slow enough for final descent. Once you're above 80 km, aerodynamic pressure will not be sufficient to steer you back down no matter how you rotate, and you bounce off the atmosphere for another orbit which may be fatal if you have a life support mod enabled and limited resources in the capsule (which will be out of its service module by then). So in short: aim for a low periapsis, switch capsule in Descent Mode before hitting the atmosphere and rotate to a neutral-ish position, wait until you see your g-forces raise to 3-4g or so, rotate capsule such that it goes up again, once you are nearing 70 km steer down again so you stay below 75 km or so. Continue to control your descent path to keep g-forces on a healthy level. Once you're slow enough, just let it fall down. I recommend quicksaving and practicing until you got the hang of it.

Well, unfortunately it didn't fix the issue. I believe it stopped the explosion, but it still had an ejection force way too high. So pretty much what chrisl is seeing. The other bug I had around that time (end of January) was that SM and CM didn't properly decouple. I didn't have a problem with spinning, but the SM would decouple and then immediately latch on again, but slightly skewed. No way to get those separated properly other than reloading and trying again a few times, or rotating quickly enough to get the thing thrown away before it could latch on again. That said, I didn't get around to play KSP since end of January. I did try your (not really) fixed .mu and ran a mission with it, with the above results. But I can't say if things have improved in later updates.

Well. Now it no longer explodes, but it still is a rather violent separation, sending both parts of the spacecraft tumbling away at a good amount of speed. I guess that one could be fixed by lowering the ejection force though... I assume the fix was removing/fixing a collision with the fairing base that caused the original explosion? However, that still doesn't affect the decoupler itself. I wonder if this thing should be a docking port instead, or a stack separator rather than a decoupler. Or it needs its parameters tuned at least. Or the special part used in stock FASA ported to RO. Anyway, at least nothing got damaged, the spent stage was accidentally put on its intended collision course with the Moon, and just 2.5 m/s of course correction also sent Apollo back onto its intended path. So I can continue the mission at last!

Finally got around to launch another Saturn V, with up-to-date RO (10.8.0) and FASA (5.44). Got into orbit ok, did the transposition dance - and when triggering the LEM decoupler, the whole thing exploded again. So this issue isn't fixed for me. Is there anything I can do to (help) debug this?

Yes, I did install 5.44, although the craft that's in the savegame is from an older version. I assumed that bugfixes in parts would automatically propagate; but I can give it a go with a new game. More practice for the gravity turn won't hurt, eh? I assumed that the RO version of the Saturn V is different from the FASA one, because I can't even load the one shipped in the FASA Sandbox into the VAB (just the capsule shows up, and it looks completely different). EDIT: ... and the RO version doesn't have floats and uses a different decoupler, correct?

So I was giving RO's FASA Saturn V/Apollo stock craft a spin. Launch went ok, transposition went ok - but when I try to decouple the LEM from the third stage, the whole thing violently explodes. Last time I was trying out this stock craft was still with KSP 1.0.4 (and I think RO 10.2, but I may be mistaken), and I distinctly remember that there was an explosion effect when decoupling the LEM that most likely shouldn't be there. But at least there was no actual explosion involved back then. But now the whole thing gets ripped apart, and fragments fly away spinning in all directions. Tried editing the savegame and lowering the ejection force of the decoupler in question (stackSeparatorMini), but no change. Checked the FASA mod, and noticed in the ChangeLog a bunch of changes related to collider meshes and exploding decouplers, also affecting their version of the Saturn V/Apollo. Had a look at their craft file (which I assume isn't tuned for RO/RSS...), and funnily enough they don't even seem to have a stackSeparatorMini in there... So... any chance to get this fixed? Or maybe even a workaround for now, so that I can continue the mission? Since NathanKell now is involved in both RO and FASA, can we expect an update of the RO version based on the seemingly more advanced FASA one? Thinking of, for example, the floats for the capsule... and of course non-exploding decouplers

I had this issue when using the Mk16 parachute with RO. All other parachutes seem to work fine. Not sure if this bug has been fixed recently; haven't tried out Mk16 in a while...

No worries, it just sounded like people were already toying around with a newer version, so I wondered if there was an alternative download location that I missed or somesuch Take your time, I know how it feels to be swamped in RL stuff...

Have there been any updates to the 64 bit version since beginning of August? I don't see any relevant commits on Github, but maybe I missed a memo somewhere

I managed to get the Saturn V/Apollo all the way to the Moon, landed, and got back to Earth with some fuel to spare in both the LEM and the Service Module. Have yet to try reentry to complete that mission (loading up the game as I write this...). Since you seem to have trouble: Did you follow the actual mission profile? I used NASA material to tweak my trajectories to the point where I managed to be very close to real life in my replay. You have to have a surprisingly shallow ascent path if you want to get into orbit with enough fuel left. First stage should burn out at around 70km height at a speed of around 2.5 km/s. Second stage should get you near an apoapsis of 190 km and a speed of around 7 km/s. Third stage should only use up around 500 m/s or so for circularization, and then have enough fuel left to get you all the way to the Moon (aim for a translunar injection profile that brings you close to escape velocity, i.e. around 10.8 km/s if I recall correctly; that way you need less fuel from the Service Module for the capture burn). Aim for a 110 km orbit. Once you're in lunar orbit, you should have plenty of fuel in the LEM to get you down and back up again. You can increase this if you use the SM to lower your periapsis to about 15 km before detaching the LEM. Once you're ready to depart to Earth, you should have at least 1200 m/s left in the SM (with no LEM attached, of course), and that is plenty to bring you back home. Also note that in the stock Saturn V from FASA, all upper stages have their fuel and resources disabled, so you don't drain them prematurely. You have to right-click the parts and re-enable resource flow before using them. Also, don't forget to activate your CO2 scrubbers and fuel cells, otherwise your crew won't survive the trip and you'll run out of power. Good luck!

Speaking of example vehicles... let me take the opportunity to thank everyone involved for the stunning Saturn V/Apollo replica that comes with FASA and RSS/RO. I'm currently re-enacting the Apollo missions just using the replica, without any tweaks on my side (other than adding a launch tower for looks). I mostly use real NASA sources for figuring out the numbers (such as ascent trajectory, orbit heights, burn times etc.), and they work just fine with the provided Saturn V. There's exactly as much fuel (water, food, oxygen...) in the various stages as is needed for the NASA-defined mission profile. Not only that; but the recent updates setup everything correctly - ensuring that staging works as it should, that fuel and other resources get drained in order, that I'm not using the RCS fuel from my capsule when I still have a S-IVB, and all that... just works out of the box. So, yeah. Thank you!

Heh. Again I don't know how SMURFF works in relation to Realism Overhaul... but keep in mind that the original Saturn V + Apollo was *massive*. 110m high, 10m wide, weighing 3000 tons, to get three men to the Moon. A tad more than your measly 41m x 2.5m rocket While getting into low Earth orbit is "easily" doable considering you need about 10 km/s of dV, getting to the Moon and back requires another 7 km/s or so... and that does not include the lander and its fuel to get to the surface and back (another 5 km/s). So in total we're talking about 22 km/s of dV, plus all the additional hardware for landing, plus of course you need to lift all that from the ground. Twice. So, yeah. A rocket getting you to the Moon and back will be *much* bigger than one that just goes into LEO. Space travel is hard, and there's a reason why Apollo was prematurely canceled and noone went back to the Moon since Funnily enough, getting to Mars does not require much more delta-V (although landing and take-off are more challenging). The Falcon Heavy is half the size and mass of the Saturn V, and able to get 14 tons to Mars (but not back)... Realism Overhaul actually comes with a Saturn V replica that seems to be pretty close to the original. I'm currently on a mission to recreate the Apollo flights using that thing, and so far I could just follow official NASA material for flight trajectories etc, with the fuel just being enough for every step (as it should be), and travel times etc. pretty much in line with the real missions. I have yet to land on the Moon to see if the LEM behaves like reality as well, though

Orbital speed in Low Earth Orbit is around 7.5 km/s or so, so the 9.1 km/s of launch dV seem to be largely plausible to me. Probably more than that, if you're not hitting a near-optimal ascent trajectory. I haven't played RSS without Realism Overhaul, so I can't say anything about that combination. But at least with Realism Overhaul, building something small that goes into orbit isn't particularly hard, and doesn't require huge parts - real life fuels and engines provide much more delta-v than the parts in the stock game (mostly because the parts in the stock game have been gimped so achieving the measly 3500 dV you need to get into Kerbin orbit is still some sort of a challenge). You can build a multi-stage sounding rocket that manages to bring something Sputnik-like into LEO...

Thx for the reply; I guess it'd be even easier (and more useful) to just grab RP-0 as a whole from Github. NK tends to ship the DLLs in the repo, too. But my main question was if pingopete would be willing to update his Linux64 branch for RVE itself; I'm sure there were lots of neat things added in the past month that I'd love to tinker around with