Can a pressure fed engine be powerful enough to augment the landing of Starship on the Moon? How much thrust is needed to land SS if it’s brought to zero velocity at an altitude of 10 meters?
A debate exists whether SS is will kick up debris harmful to itself and others. Do not want to engage that debate here. But to address the possible need for alternatives: Posit the Raptors will bring SS to zero velocity at 10 meters altitude, instead of zero altitude, keeping the worst of the exhaust plume from the surface. Can a hot gas thruster, or cluster of them, be powerful enough to ease the final 10 meter descent? This will be the simplest additional system since SS will have an RCS of methalox hot gas thrusters. (The proposed thrusters to be larger but similar.) Assume a wet mass on landing of 240t; a modest payload and fuel to reach lunar orbit.
Know this is not the forum for the many issues surrounding Starship lunar missions, but want to know if this one aspect is at all workable.
(10 meters is an arbitrary starting point, but if this won’t work there, or lower, the question is moot.)