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They should use a Starship rather. Much quicker. The only hurdle would be the price.
by kaptainscarlet 1y ago
They should use a Starship rather. Much quicker. The only hurdle would be the price.
- wat10000 1y agoAnd the dying in a fireball. Starship’s design seems fundamentally impossible to make safe.
- somenameforme 1y agoThat's akin to saying that it seems fundamentally impossible to make landing rockets safe which, in fact, is exactly what Boeing/Lockheed were saying when SpaceX was first revolutionizing that space as well.
- wat10000 1y agoI’m not aware of any rocket landing safe enough for human use. NASA nixed the idea of propulsive landing for Dragon 2 for this reason. It’s extremely difficult to make safe, since just about any reasonable engine configuration means guaranteed death if a single engine fails at a critical moment. Compare with modern airliners where an engine can fail at any point in flight and the plane can land safely. So yes, I agree, it is akin to saying that.
- panick21_ 1y ago> NASA nixed the idea of propulsive landing for Dragon 2 for this reason. That is completely false. First of all, NASA didn't nix it, they just didn't make it a priority as it had little value from their perspective. The reason it was not done is that para-shouts have to be in the design anyway for abort situations, so that was fixed. So for SpaceX, the question was to likely delay the program, and take on a whole lot of extra engineering work that they were not actually getting paid for, remember fixed price contract. They were only going to work on it if they really thought they needed it for something like Red Dragon. And then they could still add it later. And one of the primary reason SpaceX thought that its to hard, is that they landing feet would have to have gone threw the heat shield. That would have made the whole heat-shield design massively more complex.
- wat10000 1y agoSome dude who runs SpaceX seems to think the reason was safety. https://x.com/elonmusk/status/1104509345922838528 https://x.com/elonmusk/status/1104509345922838528
- somenameforme 1y agoHe said it was the difficulty in proving the safety. There's an informative article here. [1] NASA likes parachutes because they've always used parachutes. SpaceX likes retropulsive landings because Mars is their goal, and Mars' atmosphere isn't dense enough for parachutes. It's also safer for the crew in nominal operation and enables a much higher degree of rapid reuse, relative to NASA's traditional operation of taking a salt water bath in the ocean. So they could go through the [very reasonable] extensive costs and testing involved in proving the safety of the retropulsive landings, or just go old school, strap a few parachutes on and work on getting crew to the ISS (which was the goal at the time). They chose the latter and with the plan of getting back to retropulsive landings later, which they also did. Parachutes remain the main landing mechanism for the Crew Dragon, but it now also has retropulsive landing capabilities to be used in case of a chute failure. [1] - https://www.nasaspaceflight.com/2024/10/dragon-propulsive-landing/ https://www.nasaspaceflight.com/2024/10/dragon-propulsive-la...
- wat10000 1y agoIn what sense can it be called safe if you haven’t proven it?
- somenameforme 1y agoThey had repeated successful demos of it, but NASA kept adding on new requirements while implicitly signaling that they had no interest in approving the system, which would have made Boeing's lander look obsolete before it was ever finished. NASA's judgements are heavily influenced by external factors that make it quite difficult on outsiders, while enabling reckless behaviors for insiders. For example NASA deemed the Boeing crew vessel safe after its pad abort test resulted in only 2 of 3 parachutes deploying and it suffering a propellant leak - all in beyond optimal conditions. They deemed it not only safe, but safe enough to completely skip the scheduled in-flight abort test. All of this is of course how you ended up with astronauts trapped on the ISS that had to be rescued by SpaceX. For another contrast there after SpaceX did swap over to a simple parachute system, their pad-abort test went off flawlessly. NASA still required they do an in-flight abort. Granted, that's nothing to complain about, because that's exactly what NASA should do. But they also should have had Boeing completely redo their pad-abort test and damned sure do an in-flight abort as well. Safety culture at NASA is generally completely dysfunctional because of non-safety factors. This is nothing new either. Both Space Shuttle disasters were 100% preventable, and not only in hindsight. Engineers brought up the exact causes of both explosions well before they happened, but the bureaucratic layer ignored them.
- cnlevy 1y agoSoyuz uses propulsive landing
- numpad0 1y agoAnd that's why astronauts preferred the Shuttle
- 0_____0 1y agowhat, the puff of impulse at the end of the parachute descent? I thinks it's a bit disingenuous to call that propulsive landing without context
- cnlevy 1y agoYou're right; I meant to refute the following point: NASA nixed the idea of propulsive landing for Dragon 2 for this reason (safety) It wasn't because of safety, but because it would have needed tests, development and certification (for a new type of landing) while already having an established method (splashing into the sea).
- wat10000 1y agoSoyuz lands by parachute. It uses a rocket at the very end (literally two feet off the ground) to cushion the impact.
- mr_toad 1y ago> I’m not aware of any rocket landing safe enough for human use. I’m pretty sure the Eagle has landed with humans on board.
- wat10000 1y agoPretty much nothing about Apollo was safe, even by the relatively low standards of modern space travel.
- voidUpdate 1y agoJust to be a little pedantic, humans have done propulsive landings before. The Apollo moon landings were done with a rocket-powered landing :P
- consumer451 1y ago> The only hurdle would be the price. This is not the only hurdle. You can have an airport right next to a major city, with hundreds of arrivals and departures each day. The same cannot be said for a Starship spaceport. Due to very loud launch, sonic booms on landing [0], and the danger of dropping a Starship onto populated areas, it would likely need to be offshore. That requires a boat, so now boarding a Starship involves thinking about sea states, taking a ferry ride on each side, and more. Starship is super cool, but point to point Starship is a bit of a fantasy when you start to get to the nitty gritty. [0] https://www.nasaspaceflight.com/2024/11/starships-sound-study1/ https://www.nasaspaceflight.com/2024/11/starships-sound-stud... (TL;DR: Super Heavy's sonic booms are 110 dB when standing 20 km from the booster.)
- gmueckl 1y ago110dB 20km from the origin? That is a serious WTF right there if that number is accurate. If my quick estimate is correct that would mean that the sonic boom is deadly to anything within a few 100m around the booster. Even 110dB is skirting the border to permanent hearing damage from a single exposure.
- HPsquared 1y agoThe launch (engines etc) are MUCH louder still.
- mr_toad 1y agoBoth the Saturn V and the SLS produced over 200dB. Considering that the scale is logarithmic the sound must be quite literally staggering. https://www.theoverview.org/p/sls-vs-saturn-v-which-was-louder https://www.theoverview.org/p/sls-vs-saturn-v-which-was-loud...
- gmueckl 1y agoHere's some noise data from Starship launches. This says that it emits over twice the acoustic energy of SLS at launch: https://pubs.aip.org/asa/jel/article/5/2/023602/3337259/Starship-Super-Heavy-acoustics-Comparing-launch https://pubs.aip.org/asa/jel/article/5/2/023602/3337259/Star...
- tjpnz 1y ago>The only hurdle would be the price. And that suborbital spaceflight is effectively off the table for anyone with a heart condition. There's a reason why you see all those warnings on rollercoasters even when the dangerous part lasts <1s. Now let's subject someone to minutes of it.