The Great Ongoing Space Exploration Thread

T-11:03, another hold.

I think this is a standard hold for a go-no-go check. Too bad we don’t get to hear mission control.

Ahhh! The inevitable wayward boat!

T-7:30. Sounds like go all around.

ETA: T-one minute!

Oooh, those are some nice looking mach diamonds.

ETA: They definitely need some Starlinks for their cameras :slight_smile: . Pretty crummy video feeds once it got to stage 2.

ETA2: Hmm, no telemetry or video for a while from Stage 1. Mission control said they’re getting data, but… doesn’t look great.

ETA3: Kinda forgot how long it takes hydrogen stages to get to orbit. Such low thrust! But it’s still going.

ETA4: They hit orbit. Yay! Guess they only went for a 100 mile orbit, which is fine. No word on the booster, though.

Looks like I wasn’t crazy–the rocket seemed very slow off the pad, and other people noticed the same thing. Thrust/weight ratio is probably around 1.2. Quite low compared to the Falcons and Starship (which are more like 1.5). Nothing wrong with that per-se (Saturn V was also 1.2), but sorta anxiety-inducing when you don’t expect it.

It wasn’t heavily loaded, just that blue-ring thing, so you’d expect better ratio. Unless there was a lot of ballast that they didn’t mention.

Or the first stage somehow underperformed but not badly enough to jeopardize an acceptable trajectory. But I doubt that could happen.

The payload would not have directly made much difference. The engines are 250 t thrust each, so 1750 t thrust total. The max payload is 45 t, which is only 2.6% of the total. Just not a big difference.

It’s possible they deliberately underthrottled the engines for more reliability. It would be at the expense of performance, but it was a small payload. The first stage would be going more slowly at separation, which might also make easier conditions for landing.

I think it’s just designed this way, though. SpaceX favors high T/W and squeezing as much as they can from their engines. Other rockets often have solid boosters and those inherently have high T/W off the pad. So New Glenn looks slow but isn’t all that crazy. And it’s also big, which makes it look slower yet.

I think their first stage is kinda heavy, too. Their landing gear and fin system just seem a bit bulky to me. This could imply that the stage has high fixed mass, but not necessarily high marginal mass–that is, it’s cheap to stretch it a little to add more propellant. That would favor relatively low T/W.

Starship is going for high T/W in part because it requires less propellant (less gravity losses, which are pure waste). New Glenn will never be cheap enough to where propellant costs are a significant fraction of launch costs, but Starship might. So that changes the tradeoff as well.

The phrase “rapid unscheduled disassembly” is very clever.

SpaceX’s giant Starship rocket blows up in ‘rapid unscheduled disassembly’, says company | The Independent

There’s a bit more conversation happening in the dedicated Starship thread, BTW:
https://boards.straightdope.com/t/starship-development-and-progress-previous-title-will-musks-starship-reach-orbit-this-year

Rapid Unscheduled Disassembly (RUD) is a fun phrase, but it’s been in use for a while now. Aerospace engineers love these sorts of euphemisms, such as lithobraking (slamming into the Earth) and engine-rich exhaust (exhaust can be fuel rich or oxygen rich, but engine-rich means that the engine itself is burning).

Big sigh.

I haven’t seen any coherent explanation for what this is about. About the best I can come up with is that nothing will actually change at all, and this is just a way of Trump claiming credit for something that was already going to happen. Which could loosely be described as SpaceX saving the stranded astronauts, but that isn’t exactly the fairest way of describing the situation.

At most, this would imply moving the schedule up a bit… doable but also largely pointless, unless there’s an increasingly urgent health scenario we don’t know about, or some other problem along those lines. Seems unlikely.

“Whatever you do, don’t squeeze!”

And a bit of explanation:

NASA should soon announce a new plan for the return of two of its astronauts, Butch Wilmore and Suni Williams, to Earth as early as March 19. This is about two weeks earlier than the existing public timeline for their flight home from the International Space Station.

At this point, if NASA waited for C213 to be ready to launch the Crew-10 mission, the space station program would start to approach ‘redlines’ on food, water, and other supplies for crew members on board the station. The agency is also juggling a lot of competing priorities in terms of cargo and crew missions to the station. The bottom line is that they really needed this crew rotation to occur sooner rather than later.

So not a political stunt–just a pragmatic schedule shift that was spun as a “save our astronauts” thing. The spin was silly but the actual decision was not.

Artemis:foul?

Perhaps it’s been telegraphed that zeroing Artemis funding is part of DOGE’s big list of early projects vandalisms.

Although Artemis/SLS has only lasted this long due to pure pork-barrel politics. It should have been cancelled well before the Trump administration.

Granted. But shutting down the only semi-competent space contractor not controlled by madman musk is also doubleplus ungood.