SpaceX and NASA Learned to Land on Mars by Studying Falcon 9 Landings | NextBigFuture.com

On September 29, 2013, SpaceX performed the first supersonic retropropulsion (SRP) maneuver to decelerate the reentry of the first stage of their Falcon 9 rocket.

NASA asked if their EDL (entry, descent, and landing) engineers could watch and study SpaceX’s data, and SpaceX agreed. Beginning in 2014, NASA and SpaceX worked together for three years. They SRP analyzed SpaceX Falcon 9s for the NASA Propulsive Descent Technology (PDT) project. The F9 boosters were outfitted with special instruments to collect data specifically on portions of the entry burn which fell within the range of Mach numbers and dynamic pressures expected at Mars. Additionally, there were visual and infrared imagery campaigns, flight reconstruction, and fluid dynamics analysis.

There is a lot of fuel management issues for a SpaceX Mars landing. This is reviewed in the video below. If there was a fuel depot created on Deimos (Mars Moon) then it would become far easier and safer to land on Mars.

Mars’ thin atmosphere (1% of Earth) provides challenges not found on Earth or the Moon. A large, heavy spacecraft streaking through Mars’ thin, volatile atmosphere only has just a few minutes to slow from incoming interplanetary speeds to under Mach 1, and then quickly transition to a lander to slow to be able to touch down gently.

Using thrusters creates a shock front ‘bubble’ created around the vehicle by firing the engines somehow insulates the spacecraft from any buffeting, as well as from some of the heating.

EDL engineers now believe that SRP is the only Mars entry, descent and landing technology that is intrinsically scalable across a wide range and size of missions to shed enough velocity during atmospheric flight to enable safe landings. Alongside aerobraking, this is one of the leading means of landing heavy equipment, habitats and even humans on Mars.

There are still multiple unknowns for landing a spaceX Starship on Mars.

How a big ship such as SpaceX’s Starship would be steered and flown through Mars’ atmosphere?

Can fins be used hypersonically or will the plasma thermal environment melt them?

The amount of debris kicked up by large engines on human-sized ship could be fatal, especially for the engines you’d like to reuse for returning to orbit or to Earth, so how do you protect the engines and the ship?

Mars can be quite windy, so what happens if you encounter wind shears or a dust storm during landing?

What kind of landing legs will work for a large ship on Mars’ rocky surface?