18 thoughts on “The Path Forward In Space”

  1. It’s easy to forget that the manned Dragon will, in principal, have the greatest potential for safe aborts than any manned spacecraft in history. Certainly more than the Shuttle with it’s SRBs and bailout “capability”, even more than Apollo/Gemini with their all liquid stages and tractor abort system. If there was a strong need to put crew in orbit before the full manned Dragon systems are online it could certainly happen much sooner, and realistically be no less safe than the Shuttle overall. One of the more pressing constraints is just to update the launch pad, but there are ways to workaround that with cobbled together interim solutions.

    1. The gist I’m getting is that we’d probably be willing to lose ISS rather than fly without a LAS or on a launch vehicle (F9 1.1) that’s had only a few launches. The excuse is risk.

      Contrast the above with this; the powers that be are at least considering a manned Mars flyby in 2021. It’s be the second flight of the launch vehicle, sort of; it’s be the first in an upgraded configuration with significant new hardware (such as the upper stage). You’d also by flying the first manned mission with the capsule, and a modified one at that. A whole new life support system and architecture too. And as for abort capability; okay, you’re in LEO and start your TMI burn. Remember, this is the *first* flight of that upper stage, and one that had to have its development massively accelerated. So, you’re a few minutes into your burn and there’s a problem (Say, a broken fuel line), causing the stage to shut down. It does so safely. The crew and vehicle are fine, except they can’t relight the stage. Their spacecraft, of course, has no significant delta/v of its own (They are not taking along an Orion service module – they can’t) They’re not far from Earth, they’re still well inside GEO, outbound at absolutely any velocity between earth escape and their optimum departure velocity; it doesn’t matter. What are their abort options? Exactly none. They’re dead, it’ll just take a while, because they have no way to get home. And that’s just one issue in the no-abort-option category, there are many.

      And that Mars flyby is being considered by the same folks who say we can’t fly astronauts without a LAS, perhaps even in an emergency such as loss of access via Russian Soyuz to ISS.

      1. the powers that be are at least considering a manned Mars flyby in 2021.

        No they aren’t and at least partially for the scenario that you paint. The other is that there is no money for it.

        1. If they aren’t at least (some of then anyway) considering it, why did they hold hearings on it? Granted, it was probably mostly a propaganda exercise for SLS, but I don’t think it would have gotten this far unless some the congresscritters were considering it.

          1. Propaganda exercise is right. There is light years between the level of consideration that happened vs what it would take to do fund the mission.

          2. Dennis Wingo said; Propaganda exercise is right. There is light years between the level of consideration that happened vs what it would take to do fund the mission.

            I hope you’re right, but I’m far from sure. I think there’s an odds-on chance that some funding will be dedicated to this mission. (For example, to speed up SLS second stage development)

            What I don’t see ever happening is this mission ever flying. But, that won’t stop them from spending money on it, alas.

    2. Falcon/Dragon don’t have enough flights yet for a strong statistical safety record. On the other hand, Mercury, Gemini, Apollo, and the shuttle where launched with crew on an even shorter statistical records. SLS/Orion will never have enough launches to match the statistical record Falcon/Dragon already has.

    3. Certainly more than the Shuttle with it’s SRBs and bailout “capability”, even more than Apollo/Gemini with their all liquid stages and tractor abort system.

      Not disagreeing in the slightest with your main point, just nit-picking to point out that Mercury and Apollo used tractor abort systems. Gemini had ejection seats. Shuttle, of course, had nothing at all and the first flight of the most complicated aerospace vehicle ever built had crew on board. They also had ejection seats but I’m pretty sure the escape window was pretty short.

      1. Right, I forgot about Gemini’s ejector seats. In any event, it’s amazing how fast people forget how lacking the Shuttle system was in reliable abort capability.

    4. “It’s easy to forget that the manned Dragon will, in principal, have the greatest potential for safe aborts than any manned spacecraft in history…. even more than Apollo/Gemini with their all liquid stages and tractor abort system.”

      How is Dragon’s abort capability any greater than Apollo’s?

      1. It has utility on nominal flights. Also, it doesn’t have a failure mode that can kill the crew on a nominal flight (e.g. failure to jettison).

        1. In addition, if my guess is right, Dragon’s LAS has possible abort modes throughout ascent. Apollo’s LES didn’t, due to jettisoning shortly after second stage ignition.

          The thing I like best about Dragon’s LAS is it serves a purpose on a nominal flight; it’s not just dead weight.

          1. I do like Dragon’s abort system for the reasons Rand outlines, but it’s just not true that Apollo didn’t have abort modes throughout ascent to orbit. After jettison of the escape tower, Apollo had abort modes (Nos. 2, 3 & 4) using either the service module or the S-IVB. Claims to the contrary are SpaceX propaganda, as are its claims that Falcon Heavy will be the largest rocket to fly since the Saturn V (Energiya, anyone?).

    1. Pretty cool stuff, although this is mostly just a collection of old news.

      One thing I wonder about is whether or not SpaceX will try to pioneer 2nd stage reusability with the Falcon 9. Economically it’s somewhat hard to justify in the short term since apparently they can get to around $5-7 mil. per flight with just 1st stage reuse, and there’s no way the competition is going to catch up with that by the time the MCT is flying.

  4. I just want to add that I thought the article was excellent, and raises superb points.

    I was aware that the initial SLS second stage was delta/v short, but I wasn’t aware that it was quite as bad as the article shows. It’s even worse than I thought.

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