[ThisIsTheWay]

One reason that comes to mind is that it would be a totally new use case for Dragon capsules. SpaceX had originally planned them to use propulsive landing on return to Earth, but abandoned that plan in lieu of more traditional water landing returns. To land on the moon (and Mars) they will need to pick up where they left off and continue with the propulsive landing plans, albeit in a much lower gravity environment.

https://spaceflightnow.com/2017/07/19/propulsive-landings-ni...

[Tepix]

I don't think they are planning to use Dragon capsules for Moon landings. They want to use their new Starship and probably equip it with some extra rocket engines near the top of the spacecraft so when landing it won't kick up dust and rocks into Moon orbit and beyond (yes, that would happen with the rocket engines at the bottom because Starship is so big!)

[Buttons840]

I'm not sure a rocket landing could blow a rock into a stable moon orbit. Blow them to escape velocity maybe.

But if a rock is "in orbit" after being blown upward and away from the moon's surface, then wouldn't its "orbit" pass beneath the moon's surface?

[simonh]

That assumes the potentially chaotically turbulent, expanding blast of exhaust gas propelling these rocks only imparts a single instantaneous linear impulse. It's possible some rock fragments might be kicked up from the surface, and then accelerated laterally away from the landing site by the gas cloud.

[Diederich]

Perhaps? Delta-v from the surface of the moon to orbit is about 1.6 km/second, though debris from a landing would be approximately instantaneous thrust, which doesn't allow insertion into an orbit.

[Diederich]

> ... probably equip it with some extra rocket engines near the top of the spacecraft so when landing it won't kick up dust and rocks ...

Correct: https://spaceflightnow.com/2020/05/01/nasa-identifies-risks-...

[handol]

It's not Dragon, it's a variant of Starship.

The three proposals they were selecting between: https://www.nasa.gov/feature/nasa-selects-blue-origin-dyneti...

[bryanlarsen]

SpaceX's lunar proposal uses Starship, not Dragon.