Aerobraking multiple ships, the ship I'm not flying disappears like it crashed

[CastrolGTX]

Quickly, it's a mission to Duna with two pieces, a rover and leg-lander. They detach high over Duna while on a course to aerobrake with about 10km periapsis, starting at around 4000m/s, and are meant to land with parachutes plus engines. They're also far enough apart that I can't use [ or ] to switch between them, Flying either ship I discover that shortly into aerobraking, the other has disappeared from map view. Also, flying either ship, I find that they both don't actually aerobrake enough to land the first time around. So I know for a fact that neither ship could crash without firing engines first. Even then, they disappear way before impact would have happened, it's as if they're crashing into the atmosphere and dying.

Is there a height limit that the game just considers impact for ships you aren't flying? Would it help if I got them within render/physics distance before aerobraking?

Edited October 24, 2013 by CastrolGTX

[blizzy78]

Is there a height limit that the game just considers impact for ships you aren't flying? Would it help if I got them within render/physics distance before aerobraking?

Yes and yes. Also, the other vessel would need to stay within physics range. If it doesn't... well you already know how that works out.

[buzzles]

If I remember correctly (someone can correct me), ships/objects that aren't under control of the proper physics engine get deleted if their path takes them under 25km from a planet/moon surface.

[Kasuha]

On Kerbin it's at below 23 km and the ship gets deleted if its distance to the controlled ship is 2.5 km or more.

[Specialist290]

The general rule of thumb is that anything that passes below the 0.01atm threshold while "on rails" (i.e. not actively loaded into the physics engine) is deleted. The exact altitude varies from planet to planet; like Kasuha mentioned, it's around 23km for Kerbin.

[Skorpychan]

I made that mistake on one of my earlier science missions. The first attempt lost the science pods to parachute shock, the second slammed into the ground due to lack of chutes, and so I decoupled them with their own chutes on the third attempt. The pods vanished without trace, even with chutes attached and deployed.

[boomerdog2000]

Same. On my recent mission to Eve I detached a probe lander from the mother-ship before the initial aero-braking thinking both would aero-brake successfully. I ended up aerobraking the whole ship, then detaching the probe at apoapsis before raising the mothership periapsis. So the probe could land while the mothership was in orbit.

[Mykill Metal]

It's not like there's life support systems yet. Why not just send them one at a time? Also, aerobraking on duna is inadvisable with its low gravity and thin atmo.

[Thogapotomus]

Aerobraking on Duna is the best! Screaming across the surface just a few km up while on fire is awesome