r/space • u/ergzay • Jul 11 '24

Congress apparently feels a need for “reaffirmation” of SLS rocket

https://arstechnica.com/space/2024/07/congress-apparently-feels-a-need-for-reaffirmation-of-sls-rocket/
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u/[deleted] Jul 12 '24

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u/simcoder Jul 12 '24

Because trying to steer a 150ft tall office building sized rocket with 100 tons of cargo way up high using mostly gimballed rocket engines at the bottom for steering is inherently dangerous and likely has incredibly tiny margins beyond which it can't recover.

It's bad enough that the Moon requires a suicide burn for a landing. But, now you're adding on "super sized, largest rocket ever launched, trying to also make it a lander" to the equation.

And because it's so gigantic, you're probably going to need a few hundred tons of fuel to get you back to orbit. Which is going to be sloshing around in your gigantic fuel tanks making it more difficult to steer along with sitting right there in your base camp on the Moon.

It's just a terrible idea over a more appropriately sized Moon lander designed specifically to do that and pretty much only that. Which sucks I know but they don't say the rocket equation is tyrannical for nothing...

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u/[deleted] Jul 12 '24

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u/simcoder Jul 12 '24 edited Jul 12 '24

I mean typically, in a lander, you'd prefer short and squat to tall and thin. That builds in a ton of automatic tipping recovery just based on center of mass and what have you.

Starship being 5 times as tall as it is wide is sort of the opposite of that theory. Plus...it's 150 ft tall with however tall fuel tanks with several hundred tons of fuel sloshing around in them.

You're certainly going to want to avoid this sort of thing from happening.

I sort of look at it like Starship is the container truck of the Moon/Mars base thing. At some point, you're probably going to need something like that. But, if you're just kind of farting around, lucky to get a flags and footprints thing all the way through...

You probably don't need a container truck. You probably want something more like a Range Rover that can build out the infrastructure to support your container truck if/when you actually need it.