281–290 of 1001 posts
[stub for offtopicness]
[flagged]
[1] https://news.ycombinator.com/item?id=41828032
[2] https://news.ycombinator.com/item?id=41828151
[3] https://news.ycombinator.com/item?id=41828151
[4] https://news.ycombinator.com/item?id=41828468
Earlier quoted context omitted.
Improvements that make space flight more sustainable are welcome ... unless that means an order of magnitude more pollution in a less controllable form, like emissions. [Due to more frequent flights] Daily trips to space likely also mean more debris in space and falling to earth. I hope there is a balance that includes the lives of people near these sites and all of us sharing the same atmosphere.
[flagged]
At this point I am finding it hard to hate Elon Musk. For everything he does that has annoyed me (like Gloating at people being bombed in the middle east) — his business acumen has completely unlocked for people what they we thought was impossible.
Earlier quoted context omitted.
So, reusable is supposed to reduce the cost. But the space shuttle was reusable and it has been shutdown because it was too expensive. What is the differences between the two?
Think of the word ‘reusable’ in this case as less a binary descriptor but more of a scale of reusability. Yes, both systems are reusable, but there are key differences in the refurbishment of the systems that partly explains the cost difference. It took more labor, resources and time to refurbish the shuttle. Also consider rapid reusability was a stretch goal when it was being designed, but we have come a loooong way…
Starship uses essentially the same ceramic heat shield tiles as the Space Shuttle, so the fact the Shuttle had so much trouble with refurbishment doesn't mean that SpaceX has solved these refurbishment issues with the Starship upper stage.
Though the Starship lower stage, which contains the most expensive engines, doesn't have this problem. Since it doesn't need a heat shield. So partial reusability should be pretty realistic.
Earlier quoted context omitted.
Second stage reuse seems the far more challenging problem. Other companies should have reusable boosters soon but if significant amounts of Starship continue to ablate on the way down they could be faced with a disposable Starship competing with smaller and cheaper second stages that are well sized for typical payloads. We already knew boosters can be flown back to launch sites reliably with high accuracy. We don't k…
Didn’t they look at all kinds of ideas earlier like squirting some propellant or water out over the skin on the way down, and wasn’t steel chosen for its thermal robustness? Did they get into the problem and realize it’s a lot harder and abandon those things for tiles? Maybe they will have to sacrifice more payload mass for active or passive shielding or more fuel for powered deceleration. That would yield a less imp…
[stub for offtopicness]
Earlier quoted context omitted.
Second stage reuse seems the far more challenging problem. Other companies should have reusable boosters soon but if significant amounts of Starship continue to ablate on the way down they could be faced with a disposable Starship competing with smaller and cheaper second stages that are well sized for typical payloads. We already knew boosters can be flown back to launch sites reliably with high accuracy. We don't k…
Didn’t they look at all kinds of ideas earlier like squirting some propellant or water out over the skin on the way down, and wasn’t steel chosen for its thermal robustness? Did they get into the problem and realize it’s a lot harder and abandon those things for tiles? Maybe they will have to sacrifice more payload mass for active or passive shielding or more fuel for powered deceleration. That would yield a less imp…
Earlier quoted context omitted.
So, reusable is supposed to reduce the cost. But the space shuttle was reusable and it has been shutdown because it was too expensive. What is the differences between the two?
The Shuttle consisted of the shuttle (orbiter) itself, the external tank (not reusable), and the two boosters which could be reused after ocean recovery. The orbiter itself was slow and expensive to reuse since (among other things) all the heat shield tiles were inspected and 30-100 replaced between each launch. I don't know how much work was done to the engines between launches, but SpaceX's parts and cost reduction…
Worth noting that Starship's heat shield is very similar to the one of the Shuttle. They actually got the manufacturing method from NASA.
Earlier quoted context omitted.
I think saving weight is definitely one of the main issues, see those proportionally large legs on Falcon-9, I guess it simply doesn't scale on bigger vehicles like Starship / Heavy booster. Also, by catching the booster on site, they can even save the transportation and do the refurbishing on site, so even shorter turnaround time I guess.
Also, saving on damage to the landing pad.