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A comment on After years of setbacks, NASA’s SLS moon rocket is ready to fly. Parent comment

Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by killyourcar on Monday August 29, 2022 @01:49AM (#32635139)
That said, it seems unlikely that a vehicle will go from "has never reached orbit and has a novel refueling model" to "is rated for human spaceflight" in a year or two. I think the Starship is cool as hell, but realistically we're probably looking at 2027+ before we see substantial missions on it.
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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by gpm on Monday August 29, 2022 @11:04AM (#32639163)
No earlier than dates are optimistic by nature. I could believe the dates if everything (from launches to environmental approvals) goes well, that is unlikely though.

Regardless of the dates, Artemis using starship as a lander seems practically guaranteed at this point, so SLS really is relegated to the role of unnecessary taxi...

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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by adastra22 on Monday August 29, 2022 @02:19AM (#32635264)
On-orbit refueling is neither very complex nor untried.
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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by killyourcar on Monday August 29, 2022 @02:21PM (#32641604)
Really? We've loaded that much cryogenic fuel before on a manned mission?

Pretty sure it's untried. Theoretically easy, just like launching starship is theoretically easy.

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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by adastra22 on Monday August 29, 2022 @05:12PM (#32643603)
Fuel transfer is mechanically the same whether there are people around or not, and whether you are talking 1 ton of propellant or 100 tons.
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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by killyourcar on Tuesday August 30, 2022 @02:11AM (#32647150)
It does matter if people aboard, there are more rules and procedures. You need a vessel with safeties that can allow them to eject safely if there's an anomaly.

Of course it's more challenging.

And it does matter if there's more fuel, you have to have valves and pipes that won't freeze after lengthy contact with cryogenic fuel. And you need larger pressure vessels, which scale in volume differently from surface area. It's not at all the same whether you move one ton or a hundred.

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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by adastra22 on Tuesday August 30, 2022 @02:23AM (#32647218)
The fueling is done without people onboard.
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Re:After years of setbacks, NASA’s SLS moon rocket is ready ... by killyourcar on Tuesday August 30, 2022 @09:16PM (#32657217)
But you still have to build additional safeties into the craft if it's rated for humans. A refueling craft is more complex than a non refueling craft. A crewed craft is more complex than an uncrewed craft (even if no one is aboard). A crewed, refueling craft is more complex still.
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