Rockets tipping on landing

[Loren Pechtel]

If you just bring back a capsule this isn't a problem but when you have something big enough to lug a dozen tourists around I've been having quite a problem with this.  If it goes into the water, fine, but I've tipped once even on what looked like totally flat land--and it's not like you have much choice (short of reloading and trying slightly different parameters) of where you touch down when you aren't coming from low orbit.

If it just comes apart no big deal but when one of the hitchhiker capsules blows up...  If the chutes wouldn't just insta-collapse they should be enough to avoid disaster but they go away the instant it's down but while it's still vulnerable to tipping.

I've tried landing legs, it doesn't seem to make a difference.

Do I have to take the aerodynamic penalties of a multi-stack rocket like I've been using for landing on the moons?

Should I be looking at smaller rockets and make two trips instead?  (Two hitchhikers is somewhat tippy, 3 is quite a problem but I generally have enough tourists to use the three-capsule design.)

Should I be looking at spaceplanes?  That means either over 800 m/s of fuel for orbit matching/docking or else trying to work out aerobraking and hauling along a small rocket behind a heat shield.

[Superfluous J]

There are two ways around falling over catastrophically on landing:

1. Build your ship wide. This has the problems you describe above. If you build too wide, it'll be harder to fly. If you build it "just wide enough" then it might still fall over.
2. Build your ship to land on its side. I much prefer this method. Put all the parachutes on one side, down the length of the ship. If you want landing legs, put them on sideways as well.

Note that if your ship fully lands the parachutes will go away, but if you land at a 45 degree angle and slowly "fall" over, they will NOT disappear and will help guide you down.

[Loren Pechtel]

5 minutes ago, 5thHorseman said:

There are two ways around falling over catastrophically on landing:

1. Build your ship wide. This has the problems you describe above. If you build too wide, it'll be harder to fly. If you build it "just wide enough" then it might still fall over.
2. Build your ship to land on its side. I much prefer this method. Put all the parachutes on one side, down the length of the ship. If you want landing legs, put them on sideways as well.

Note that if your ship fully lands the parachutes will go away, but if you land at a 45 degree angle and slowly "fall" over, they will NOT disappear and will help guide you down.

I never thought of chutes on only side but that certainly would fix the tipping.  Will it cause balance problems in flight?  And I've always been a bit scared of chutes that appear to project beyond the heat shield (they do draw fire during re-entry) but so far the only time I've seen chutes burned was ones on a booster.  (I use Stage Recovery and depending on the fuel I have left I sometimes manage to recover the booster.  If the fuel is low the chutes burn off but the booster would be lost anyway.)

Edited April 5, 2016 by Loren Pechtel

[Superfluous J]

55 minutes ago, Loren Pechtel said:

I never thought of chutes on only side but that certainly would fix the tipping.  Will it cause balance problems in flight?  And I've always been a bit scared of chutes that appear to project beyond the heat shield (they do draw fire during re-entry) but so far the only time I've seen chutes burned was ones on a booster.  (I use Stage Recovery and depending on the fuel I have left I sometimes manage to recover the booster.  If the fuel is low the chutes burn off but the booster would be lost anyway.)

Radial chutes are physicsless, so they add their mass to the thing they attach to. So: They won't cause your ship to become unbalanced in (space) flight. And in any case, they wouldn't be big enough to notice so long as SAS is on.

Not 100% sure on the heating up, but as they're all on the same side, just make sure that side isn't getting direct heating and you should be fine. Coming back from Mun or Minmus, you almost have to intentionally burn stuff up anyway.

Edited April 5, 2016 by 5thHorseman

[Loren Pechtel]

3 minutes ago, 5thHorseman said:

Radial chutes are physicsless, so they add their mass to the thing they attach to. So: They won't cause your ship to become unbalanced in (space) flight. And in any case, they wouldn't be big enough to notice so long as SAS is on.

Not 100% sure on the heating up, but as they're all on the same side, just make sure that side isn't getting direct heating and you should be fine. Coming back from Mun or Minmus, you almost have to intentionally burn stuff up anyway.

Ok, the chutes should be safe.  I'll redo my rocket.

As for burning up coming back from Mun or Minmus--it's not hard.  I try to recover my booster so I leave it attached as re-entry begins.  If I let it be it's certain to blow.  What I normally do is wait until it's well up in the danger zone I burn all remaining fuel and jettison it.  I have a decent chance of getting it slow enough that Stage Recovery snags it.

[Foxster]

If for some odd reason I have a wide load to get down and do need it vertical then I sometimes use Landing Gear rather than Landing Struts for their extra reach, making the base wider...

Edited April 5, 2016 by Foxster

[Wemb]

7 hours ago, Loren Pechtel said:

I never thought of chutes on only side but that certainly would fix the tipping.  Will it cause balance problems in flight?  And I've always been a bit scared of chutes that appear to project beyond the heat shield (they do draw fire during re-entry) but so far the only time I've seen chutes burned was ones on a booster.  (I use Stage Recovery and depending on the fuel I have left I sometimes manage to recover the booster.  If the fuel is low the chutes burn off but the booster would be lost anyway.)

I did a few minmus missions when I first started without landing gear and a ton of sciJrs like this once - I wasn't convinced the thing would stay upright if I EVA'd onto Minmus's surface, so I landed on the engine bell, then pitched over to one side where I had a single vernor thrusters at the top of the rocket to break the fall as it topped over. Getting back up was simple too - fire the thruster till you're at ~20 deg, then light the blue touch paper and you're away.  It's soooo wrong, but it worked.

Wemb

[Loren Pechtel]

5 hours ago, Foxster said:

If for some odd reason I have a wide load to get down and do need it vertical then I sometimes use Landing Gear rather than Landing Struts for their extra reach, making the base wider...

That looks so wrong!   But this game makes us do things that look wrong.

[Snark]

Note that you don't have to put chutes only on one side, for landing a tall skinny ship on its side.  All you need to do is to make sure that your chutes are reasonably distributed around the center of mass (i.e. don't put them all at one end of the ship), and have a reasonable amount of reaction torque available.  This will allow you to land pointed not-straight-up, so the chutes will slow your fall as you settle down to the ground.

As for projecting beyond the heat shield-- I wouldn't worry about it too much.  Chutes are reasonably tough. Also, bear in mind that the zone of protection from the heatshield is actually a narrow cone, so you have a little bit of safety zone as long as the chutes are set a ways back from the shield.  I've never had a problem with parachutes burning off.

[Loren Pechtel]

4 minutes ago, Snark said:

Note that you don't have to put chutes only on one side, for landing a tall skinny ship on its side.  All you need to do is to make sure that your chutes are reasonably distributed around the center of mass (i.e. don't put them all at one end of the ship), and have a reasonable amount of reaction torque available.  This will allow you to land pointed not-straight-up, so the chutes will slow your fall as you settle down to the ground.

As for projecting beyond the heat shield-- I wouldn't worry about it too much.  Chutes are reasonably tough. Also, bear in mind that the zone of protection from the heatshield is actually a narrow cone, so you have a little bit of safety zone as long as the chutes are set a ways back from the shield.  I've never had a problem with parachutes burning off.

I put them all on one side, it wasn't ideal but it worked.  The rocket came in sideways.  It was a water landing so tipping wasn't a problem but it would have been fine on land.  I do think I want to put a couple of legs back on, though--if I came down on steep terrain I would worry about rolling downhill.  A couple of legs would stop that.

[Wemb]

11 hours ago, Loren Pechtel said:

I put them all on one side, it wasn't ideal but it worked.  The rocket came in sideways.  It was a water landing so tipping wasn't a problem but it would have been fine on land.  I do think I want to put a couple of legs back on, though--if I came down on steep terrain I would worry about rolling downhill.  A couple of legs would stop that.

Landing something wide on a hill is always going to provide a challange.  Consider also the distribution of parachutes - you could even try overloading it with chutes - that at least might allow you to cut some at the last moment to also adjust your angle of collision with the terrain. Also, legs and RCS/vernor thrusters depending on local gravity could help with this too.

Wemb