4 ms·

Didn't we largely solve this with the sky crane for recent Mars missions?

• masklinn 3y ago
  The lander size under consideration is about 40x that of the Martian rover, I don’t know that a sky crane would work as well without a parachuting stage and atmosphere, and finally it seems rather unhelpful for taking off.
  • inamberclad 3y ago
    I presume this is part of why SpaceX is planning to use landing thrusters that are higher up the rocket.
    • moffkalast 3y ago
      Afaik that's mainly so the plume of razor sharp dust doesn't tear their engines to billion tiny pieces. Unlike the LEM, they won't be bringing a spare for liftoff.
    • rini17 3y ago
      Doubt 100meters will be enough.They need to be much higher not to kick regolith toward the rocket and beyond.
• ericbarrett 3y ago
  Velocity required to reach a 50 km orbit* above the moon's surface is only ~1.6 km/sec, and there's no air resistance to slow dust particles kicked up by the craft. For Mars, the orbital velocity is ~3.5 km/sec, thus requiring almost 5x the energy for a given mass of detritus (E = 1/2mv^2); and while its atmosphere isn't as thick as Earth's, it'll definitely cause drag for particles going that fast. * You don't quite need orbital velocity for a plume to get high enough to disrupt an orbiting craft, but it's a handy reference point.