NASA geeks code new tricks to model rocket plumes and avoid a lunar dust-up

NASA researchers have developed tools to simulate how rocket engines disrupt the lunar surface in light of plans for newer and larger landers as part of missions to return to the Moon. The Artemis program is NASA's project to return humans to the surface of Earth's natural satellite, and the landers involved will be larger and …

[Dippywood]

Supersonic hot gas not that awesome for rocky, dusty surface?????

Just being picky, but how is 'supersonic' defined in vacuo ?

The inner pedant has escaped....

[Eclectic Man]

Re: Supersonic hot gas not that awesome for rocky, dusty surface?????

Guessing that the speed of the exhaust gasses exceeds the speed of sound in those gasses.

I do wonder whether the model accounts for heat transfer between the rocket plume and the regolith, which I imagine cold be a rather computationally intensive exercise in itself.

[Julz]

Re: Supersonic hot gas not that awesome for rocky, dusty surface?????

Space isn't. No ones going to hear you scream but pressure waves do propagate in the thin stuff that makes up what we puny humans call the vacuum of space.

So what is the speed of sound in space. It varies depending upon the density of space but is approx 10-100 Km per second. The exhaust gasses coming out of a liquid fueled rocket nozzle have a speed of about 4.5 Km per second. So, not supersonic with reference to moons (lack of) atmosphere.

[Wellyboot]

Re: Supersonic hot gas not that awesome for rocky, dusty surface?????

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[I am David Jones]

Re: Supersonic hot gas not that awesome for rocky, dusty surface?????

I reckon they just used a bog standard value from earth to give an impression of speed. So faster than 330m/s or so.

[Tom Paine]

Starship...

I have a strong suspicion that, even allowing for the beer mat doodle idea of mounting the Starship landing thrusters half way up, the huge mass of the thing will mean landing will kick up so much dust that the risk of serious damage will be too high -- even if they do figure out a way to get it to stay upright after touchdown, and assuming they can scope out a large enough flat area to avoid craters or rocks and land there without a big X target to aim at, *and* work out a way for it to take off again without a flame pit. (Which they won't.) The whole "Starship on the moon" idea was obvious, ahem, lunacy from the start, and I still can't understand what possessed NASA to go for it.

(Am I right that the first landing attempt will have a crew on board?)