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by soperj 1151 days ago
> but lands with 3-6, and three of those are the vacuum variant

First stage will likely use more than 3-6, none will be the vacuum variant.

1 comments

The first stage isn’t going anywhere near lunar regolith. Ever.
You were talking about F9 landing, and taking off with 33 engines. Only the first stage lands on the F9. Only the first stage has 33 engines. I guess it's more confusing when Starship is what the whole ship is called, and possibly the second stage.
Falcon 9 is a specific clear example of landing != takeoff.

Starship != Super Heavy

Lunar Starship != Starship

Earth != Moon

All of these differences combined make the test not the slightest bit indicative of how things would work for a lunar Starship landing.

And second stage has different engines since when? Starship proper is not that different, it has fewer engines, its landing gear provides worse conditions than the launchpad.
Second stage (Starship) has always had different engines (both in quantity and construction; some are vacuum Raptors) than Super Heavy. Lunar Starship is itself a variant of the regular second stage; it'll need the cargo elevator, for example, which is shown in NASA's announcement graphics.

https://www.youtube.com/watch?v=KEnz8V97Qck&t=2100

> for the terminal descent of Starship, a few tens of meters before we touch down on the lunar surface, we actually use a high-thrust RCS system, so that we don't impinge on the surface of the Moon with the high-thrust Raptor engines. ... uses the same methane and oxygen propellants as Raptor.

(We'll see if that winds up being the actual final solution, but they've clearly at least thought about this aspect.)