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Well its ready to fly as in, one test flight. It will take 2-4 years until it will fly a second time. One of the biggest issues with SLS (besides cost) is the
by panick21_ 4y ago
Well its ready to fly as in, one test flight. It will take 2-4 years until it will fly a second time.
One of the biggest issues with SLS (besides cost) is the launch rate. It will limit the NASA for a long time.
- jiggawatts 4y agoYou forgot the launch cost! One of their single-use engines costs more than any SpaceX rocket… which are all reusable.
- syntaxing 4y agoAren’t rockets to the moon vs LEO and GEO on completely different levels of requirements?
- criddell 4y agoI’m curious about this too. Are any of the private companies anywhere near ready to send a ship to the moon and back?
- XorNot 4y agoSpaceX is closest, but no. Not until Starship flies. If history is any guide and they haven't missed any big blockers though, then they'll get there - but I think a 10 year horizon is probably a reasonable expectation.
- gpm 4y agoFalcon Heavy (existing SpaceX rocket, not human rated) can get a ship to above the moon and back today, but probably not within enough margin to land on the moon in one launch. Making a lander which launches on top of it would require substantial development work anyways, so not really close (and not planned). Starship is a SpaceX rocket reasonably late in the development cycle, and is planned to land on the moon in an uncrewed demonstration flight no earlier than 2024, and with people during NASA's Artemis 3 mission no earlier than 2025. According to the plan this will be the first mission to land people on the moon since Apollo. SLS at this point is not planning on launching a vehicle that lands on the moon, instead just a very very expensive taxi to a starship in lunar orbit which could have easily carried the astronauts there itself...
- killyourcar 4y agoThat 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.
- gpm 4y agoNo 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...
- adastra22 4y agoOn-orbit refueling is neither very complex nor untried.
- killyourcar 4y agoReally? 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.
- adastra22 4y agoFuel transfer is mechanically the same whether there are people around or not, and whether you are talking 1 ton of propellant or 100 tons.
- killyourcar 4y agoIt 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.
- elurg 4y agoYes. If you send stuff to orbit you can probably also send stuff to the Moon, it's just a payload penalty. Several Moon missions were launched on commercial rockets. Even tiny RocketLab launched one: https://en.wikipedia.org/wiki/CAPSTONE https://en.wikipedia.org/wiki/CAPSTONE
- WWLink 4y agoTo send starship to the moon takes 5-10 more starships to refuel it first. Of course, comparing orion to starship is like comparing a dragon to the space shuttle. Starship is enormous and that's why it needs so much fuel lol. I'm not saying there's room for improvement, but I think people neg Artemis way too hard for what it is. And people give Starship too much credit for what it is (so far). (And I DO like the idea of Starship and hope it succeeds). If it succeeds things will be awesome!
- midasuni 4y agoStarship hasn’t made orbit yet. I’m hopefully it will, even factoring in Elon time (wasn’t he talking about reaching Mars unmanned in 2024?) it’s slow going. I’m hopeful it will meat here falcons success, but until then compare what’s actually possible today.
- Veedrac 4y agoThat is a very unfair comparison. You are giving numbers for Starship going to NRHO, then landing the whole upper stage on the moon, then returning it to NRHO. That is a completely different ballpark to SLS's ‘dump a capsule in a lunar flyby which itself can't even get to LLO’. And if the SLS/Orion architecture wasn't so underperforming, Starship could waste less energy making up for it.
- panick21_ 4y agoNot really. If you have enough payload to LEO you can also throw something to TLI, just less. All commercial rockets like Falcon 9 or Atlas 5 can throw lots of payload to the moon as well. Even tiny rockets like Rocket Lab Electron have launched moon missions. Now what is true that the further out you go, a hydrogen RL-10 based upper stage will win out better then a Falcon 9 based kerlox upper stage. So while the payload to LEO between rockets can be pretty close, the payload to a moon orbit can be quite different.
- Aeolun 4y agoEh, once you get to orbit you are more than halfway there. Once you get to the moon you need only very little deltaV to make it back. But yeah, they’re on completely different levels.
- wumpus 4y agoI've seen a lot of people claim that, but it's misleading. Falcon Heavy is the most powerful rocket to LEO, GEO, TLI (trans lunar injection), and higher energy orbits like the ones you use for Jupiter and beyond. When SLS finishes development, it will also hold the record for all 3.
- mlindner 4y agoNo. Falcon 9 can launch objects to the moon as well.
- killyourcar 4y agoNot to and from the moon. It has a Delta v budget a little low for a full round trip that includes a landing and ascent, iirc. It could hurl something at the moon though.
- panick21_ 4y agoSLS can't do that either ...
- killyourcar 4y agoThe Artemis 3 will launch on SLS and land humans on the moon?
- Aloha 4y agoCosts will come down - while yes, it'll still be more expensive because its a heavy lift vehicle - comparing it to SpaceX is comparing Apples and Wednesday. The way SpaceX does programatic accounting, and the way NASA does programatic accounting are I suspect, wildly different. NASA itself estimates costs of about 800m+ each (depending how you account for program overhead). Also, if SLS is used to launch stuff to LEO, its a cosmic waste of money. None of the Falcon rockets can really meet the program goals of SLS.
- panick21_ 4y agoA whole number of things wrong here. First of all, that 800m number is mostly a very optimistic estimate that might come true sometime around 2030 or later. And even then its only true if you completely ignore amortization of development cost, something SpaceX can't really do. Some of the items that are getting ordered now are for rockets in the late 2020s and if you look at those unit prices its not close to 800m yet. 1b will also need a new upper stage, the price of that is as of yet pure speculation and anybody that has watched the SLS program knows that will happen before its done. And the unit price will also not be there. SLS will almost certainty be canceled before they reach anywhere close to 800m a launch. > None of the Falcon rockets can really meet the program goals of SLS. That is simply not true, or rather, its only true as so far as the whole Artemis program was designed to use SLS. When the NASA administrator suggest that Falcon Heavies could be used some in congress threatened him and seriously suggested he should resign. He shut up quite fast after that. Many at NASA in the early 2010s didn't want SLS, simple because such a rocket is not required. And even today with a few changes and tweaks it wouldn't be required. But of course if you spend 45 billion into a specific solution it will be better then the solution you spend 0$ on. But even so, its still not to late, even now canceling SLS and redesigning Artemis would be worth it. Artemis assumes that Starship will exist anyway, and human transport to LEO is fixed already. Starship is the lander already. So really, only thing you need is somehow to get humans from LEO to the moon. And guess what, Starship already has to fly that anyway.
- Aloha 4y ago> SLS will almost certainty be canceled before they reach anywhere close to 800m a launch. Thats, speculation, one covered in the source article, that notes, because of the spread of the project - virtually every state makes something for it, its proven itself more or less immune to budget cuts because of this. Beyond that, there is a dearth of heavy lift rockets out there, the idea of a single source from SpaceX is.. one, contrary to normal federal procurement rules, and two, not a sane idea - if for no there reason than it doesnt match the mission profile for a lunar mission. I'll note, that even a Block I SLS launches 30t more into LEO than Falcon Heavy does, the numbers go up even higher for later blocks, presumably this advantage is even high for lunar missions.
- Dalewyn 4y agoIt's worth mentioning the "single-use engine" you refer to is, in fact, the Space Shuttle Main Engine. Yes, those reusable engines used on the Space Shuttle.
- gammarator 4y agoBut Artemis does not, in fact, reuse them.
- Dalewyn 4y agoIndeed, my point exactly.
- bayesian_horse 4y agoNothing SpaceX currently has can bring Humans to the moon. Yes, SLS is expensive and inefficient, but it is ready to fly.
- amself 4y agoFalcon Heavy could send Crew Dragon to the Moon. They’d just have to rate it for human space flight.
- bayesian_horse 4y agoWhich means they don't have anything that can take Humans to the Moon. That certification requires the technology to be much more proven. Also Falcon Heavy only carries 26t into LEO so I actually doubt it would be enough (don't know for sure). At the very least you need a transfer stage of course. Next problem would be Crew Dragon itself. It's probably not able to return from the moon, the speed and thus the temperature is higher so you need a capsule designed for this. Which Orion is and Dragon isn't.
- adastra22 4y ago> That certification requires the technology to be much more proven. Human rating certification is more about paperwork, not technology demonstration.
- panick21_ 4y ago> Which means they don't have anything that can take Humans to the Moon. Neither does the SLS/Orion stack. What are you even comparing here? A lander is required anyway. > Also Falcon Heavy only carries 26t into LEO I assume you don't mean LEO. > Next problem would be Crew Dragon itself. It's probably not able to return from the moon, the speed and thus the temperature is higher so you need a capsule designed for this. Which Orion is and Dragon isn't. Actually, the Crew Dragon Heat Shield is designed for moon reentry. There might be a few updates for avionics but nothing to big. SLS/Orion/Orion SM and Falcon Heavy/Dragon stack are both underpowered. There are solution to this is you were willing to invest the smallest amount of money. Dragon could be extend by adding a extra fuel tank into the trunk. That would be a reasonably cheap solution. Alternatively a separately launched Service Module. That would likely cost a few 100M, but that is jump change compared to SLS/Orion. Or even better, don't launch the capsule to moon orbit at all, switch to the moon lander in LEO. Then you can simply use commercial crew to get the astronauts up and down and the lander to go to the moon and back. All of these idea would save 10s of billions.
- jvanderbot 4y agoAssuming that's all true, it will only limit NASA if they force missions to use it. Europa Clipper is not, and that's a pretty big tell.
- panick21_ 4y ago> Assuming that's all true, it will only limit NASA if they force missions to use it. That is literally why the Artemis program is designed as it is, the program is designed about the rocket and capsule, rather then the other way around. Many at NASA wanted a different architecture after Shuttle, but congress had no interest in that.
- jvanderbot 4y agoArtemis is big, but NASA is much more than that. If a Flagship mission says "no thanks", that's a serious customer speaking directly. EC is about the same size as the current Artemis program.
- Rebelgecko 4y agoAlthough it is notable IMO that EC was legally required to launch on SLS, to help justify its existence... Until there was some 11th hour maneuvering and Congress decided to rewrite the law saying that it was only mandatory to launch on SLS if SLS if SLS passed the vibe check
- elurg 4y ago> EC is about the same size as the current Artemis program. EC cost estimates are currently about 4-5 billion for the whole program while a single SLS launch is ~2 billion. The whole SLS/Orion program runs at few billion each year and it's already spent more than 10x the entire cost of Europa Clipper.
- bayesian_horse 4y agoThe rocket is the harder part in this case though. SLS was hard enough as it was, recycling existing parts. Any alternative wouldn't have been easier.
- Aloha 4y agoLaunch frequency is almost certainly a function of budget - if you want more launch, apply more budget.
- wumpus 4y agoThe best way to get high launch frequency for a crewed rocket is to have it launch on top of an existing, heavily-used uncrewed rocket. Falcon 9 and Atlas 5 are two examples. NASA's safety advisory board has said very positive things about the safety aspects of using a frequently-launched rocket.
- panick21_ 4y agoWell partially, but it would require huge infrastructure investments to get those launch rates up much. And those items have absurdly long lead times (partially by design). The RS-25E (non-reusable SSME) is incredibly complex, and you are not gone mass produce them anytime soon. Even starting a very limited production line cost billions. So sure with infinite budget many things are possible, but they are simply not going the happen. The rocket is simply not designed for high launch rates.
- melling 4y agoYes, manned space flight is slow and costly. Every few years I try to explain it but get downvoted on everything. 8 years ago we had a long discussion after the Virgin Galactic crash. https://news.ycombinator.com/item?id=8540279 https://news.ycombinator.com/item?id=8540279 Virgin Galactic still isn’t live but at the time people thought they would be by now. Anyway, since then I’ve seen Steven Weinberg’s explain my point much better than I ever could. Can’t find the entire article but here’s the first part. https://www.nybooks.com/articles/2004/04/08/the-wrong-stuff/ https://www.nybooks.com/articles/2004/04/08/the-wrong-stuff/ Unmanned is much cheaper, and we can iterate much faster.
- ghaff 4y agoI find it pretty amazing the utter lack of interest or outright cynicism about this by the HN crowd because potential future rockets may be (even very possibly will be) better. Sure, let's put all the eggs in the SpaceX basket. What could possibly go wrong? There's a lot of money being thrown around these days. It's not clear having a couple of alternate paths is the worst idea.
- panick21_ 4y agoLiterally nobody is suggesting to put all eggs in the SpaceX basket. But nice straw-men. In fact, in the current situation we have exactly this issue. SLS/Orion is so absurdly expensive that there literally is no money for dual sourcing of moon landers. NASA was forced to select on Starship as the moon lander BECAUSE there isn't enough money. If you actually read what smart pro-SpaceX analysts and journalist write, you will see that you can dual source literally every part of the architecture. We already have (or soon will) have 2 ways to go from earth to LEO. If you build on top of that, and you are not forced to spend money on SLS/Orion you have easily enough money for 2 way to get form LEO to the moon. Starhip is one of those ways, but other ways of doing the same thing could be designed if there was money for it in the budget, but that money isn't there because NASA was forced by uninformed politicians to use this architecture. Why so many people defend an architecture that is the direct result of clueless politicians I will never understand. There is a reason every other modern NASA program is dual sourced, COTS, CommercialCrew, CLIPS, Lunar resupply, suits, but somehow Artemis isn't. Why might that be ...
- macinjosh 4y agoSounds about right for a government program. SpaceX is putting them to Shane. We should just shut NASA down and privatize it’s functions. Maybe it won’t take so much time and money to actually do anything.
- idontwantthis 4y agoBold prediction: This will be the only SLS launch. It will never fly people.
- bottlepalm 4y agoAgreed, this mission will be under a microscope and any faults could be grounds to scrap the entire program - finally.
- MPSimmons 4y agoFrom your mouth to Congress's ear
- tjpnz 4y agoIf SpaceX is able to get Yusaku Maezawa and his crew of social media influencers around the moon before the end of the decade that might just happen. This does assume that NASA has received delivery of Lunar Starship which is still a big if in my mind.
- hoseja 4y agoAs if astronauts on the Moon have any real value but propaganda (social media influencing nowadays).
- natch 4y agoWe can hope. They should repurpose them as exhibits in public space centers, right alongside the space shuttles and some of the unflown rocket hardware like the actual Saturn V they have at Kennedy.
- preisschild 4y agoI'd rather see a successful SLS launch than waiting another decade...