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Comment by 0xffff2

2 days ago

It's not like SLS is on schedule either, and it is absurdly more expensive than Starship. It's very likely that Starship will eventually be operational with lower total costs by any accounting measure. (And I say this as a current NASA contractor and current anti-fan of Musk)

I agree that SLS is not an efficient project by any stretch of the imagination, and they have their own problems. I don't really see a reason to believe that Starship will ever achieve the goals that were declared for it. In particular, their plan for how to achieve the Moon mission, requiring an unclear number of missions to fuel a single flight in orbit.

  • Starship is irrelevant. SLS was dumb already in 2011 when Starship doesn't exist. Its a dumb system and was never the right system. NASA own analysis showed that.

    People who defend SLS on the bases that Starship isn't good don't get it. It doesn't matter if Starship exists. SLS should have been canceled even if you assume the state of the rocket industry in 2015.

    Anybody with half a brain and 3h time to do analysis on the topic could figure this out.

    • It's a total jobs program. I don't know what Starship will be, but at least Starship is trying to do something new and potentially very valuable. Maybe it is too ambitious but SLS is not that ambitious and not that successful :(

    • The only reason NOT to cancel SLS outright is "we can't get anything better". "Sure, it's pretty dumb, but it can be built, and good luck getting anything better built."

      Starship is important because the closer Starship gets to coming online the more obviously wrong that line of thought is.

      As is, Starship, with its first stage being online and reusable already says "we could have done something like SLS much cheaper if we were smart about it". When the second stage comes fully online, the argument for SLS will diminish further.

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  • > I don't really see a reason to believe that Starship will ever achieve the goals that were declared for it.

    If you consider declared goals for Starship to be too hard (I assume not impossible), what aspect makes them that hard?

    And since we talk about the Moon here, not stated goals of using Starships for Mars flights - what part of the Starship design makes it hard to believe that Starships may in next few years be regularly used for flights to the Moon?

    I'm curious what it is which makes it so hard to believe.

    • For me its the commodities.

      I grant that SpaceX engineers are smart people and can figure out how to make Starship and Superheavy reliable and reusable.

      But if they have to launch 10-14 times in order to get the propellant to the LEO depot in order to fuel the Lunar Starship, can we actually deliver that many launches worth of LOX and LNG to the launch pads in the timeframe needed to prevent it all from boiling off once in orbit before Lunar Starship can get there, get refueled and head to the moon? I don't know the answer to that, and to me that seems like the hard problem.

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    • All of SapaceX rockets waste close to half their payload capacity on extra fuel for landing, extra equipment for landing, and they still have a 100% failure rate on every super-heavy launch they've ever attempted. SpaceX has blown up more rockets in the last year than NASA has in its entire history. NASA's super heavy rockets have been working successfully since 1967. NASA did build the first single-stage-to-orbit rockets that also successfully landed, but it immediately realized that was a huge waste of resources. Instead, they put parachutes on rockets and then refurbished them instead. So NASA gets double the payload capacity for free. The boosters currently strapped to the SLS that's about to go to the Moon are the same ones that previously took space shuttles to orbit in the 90s. NASA has been to the Moon and Mars; SpaceX has never made it to either, and just last week Elon said they've officially given up on going to Mars, and they're hoping to make it to Moon in another decade instead. NASA is going next month. SpaceX is just vaporware being run by a drug addict whose only goal is to sell it to the public markets before the house of cards comes down.

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  • Even if Starship completely fails, SLS is a pointless and ludicrously expensive dead end. Terminating it is the only logical thing to do.

  • Is it clear how many SLS launches would be needed to subsume Starship's part of the mission?

    • It doesn’t matter because SLS can’t launch but once a year if lucky. And so far they have never even approached that.

  • You don't have long to wait to see an obvious reason, the first v3 starship is in preflight testing right now.

    • And do you think the this next launch will deploy actual satellites in orbit around the Moon? If not, I still don't see why you'd compare it to SLS's current success. Or do you think this will deploy 100 tons to orbit for less than $10/ton, or fly to Mars, since these are the stated goals for Starship?

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We have no idea what starship has cost. It's a private company.

  • I don't think "no idea" is fair. We don't have exact numbers, but there are various statements out there that give clues. Even the highest estimates I can put together put Starship far cheaper than SLS.

    • You have to consider that Starship has not reached anywhere near the operational goals for Artemis, and there is no realistic time line for when it might. So we really do have no idea how much it might cost by the time it reaches the milestone SLS has already cleared (successful flight in lunar orbit, with a full payload that it successfully deploys).

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  • True but we know for a fact that it doesn't consume 4-5 billion $ a year for the last 15 years like SLS/Orion because SpaceX couldn't afford that. If you actually do some basic math and look at SpaceX revenue and so on, you can make some pretty decent guesses. And SpaceX is analyzed in detail by lots of people.

  • Even if a Starship needs to be scrapped after landing, the Super Heavy booster works, returns nominally to the launch site, and can be reused. This alone should make the whole thing cheaper than SLS.

    • Only if the SuperHeavy booster can achieve the same performance as the SLS (payload to orbit), with similar levels of operational complexity.

      The SLS has already proven it can fly to lunar orbit and back on one single launch. In contrast, even if everything goes according to plan, Starship requires at least a dozen re-fueling flights while it hangs in orbit around the Earth to be able to then fly to the Moon.

      Will one Starship launch, when it eventually works, be cheaper than SLS? Very likely. Will 12+ Starship launches + the time in orbit be cheaper than a single SLS launch? Much, much less likely.

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