Refurbishing Rockets

Loren Grush talked to some Shuttle engineers to assess SpaceX’s chances. I’ve pointed out to several people on Twitter that Shuttle provides very little relevant experience.

[Mid-morning update]

I mentioned it in comments, but this piece I wrote at Popular Mechanics four and a half years ago is just as relevant today: Six False Lessons From The Space Shuttle:

…the reality is that the shuttle taught us nothing about the cost of a properly designed, fully reusable launch system, because that’s not what it was.

It’s a little depressing to see how well that holds up.

14 thoughts on “Refurbishing Rockets”

  1. I’m growing a little tired of the “Wait to be enthusiastic, we don’t know enough yet!” genre of articles. I know we don’t know enough yet. Soon SpaceX will know.
    That stuff about -250 Fahrenheit is nonsense, am I right? In empty space, heat loss can’t be very fast, being only via radiation. Sounds like a throwback to the “awful cold of outer space” from the cheap sci-fi of my youth.
    How much of the cost of a Falcon 9 is the thin twenty-story-tall aluminum tube, and how much is the complex machinery inside, especially the engines? Does the internal machinery really go through so much more than on a test firing, because of the “high-altitude winds” etc.?
    I’m wondering if one could design (or if SpaceX has designed) that major parts of the works are separable and could be pulled out of one ruined shell and plugged right into the next – eventually. That’s even if the outer shell is ruined.
    But we don’t know enough yet. I’ll wait to be enthusiastic.

    1. — –MikeR
      December 24, 2015 at 8:05 AM

      I’m growing a little tired of the “Wait to be enthusiastic, we don’t know enough yet!” genre of articles. I know we don’t know enough yet. Soon SpaceX will know.–

      I think we can be very happy about the SpaceX we have at the moment. And of course the Blue Origin, XCOR, Virgin Galactic, and many more efforts which includes more established space companies which are all improved by each others competition and challenges they provide.
      –That stuff about -250 Fahrenheit is nonsense, am I right? In empty space, heat loss can’t be very fast, being only via radiation. Sounds like a throwback to the “awful cold of outer space” from the cheap sci-fi of my youth.–
      I think essentially you correct. Though LOX boils at -297.3°F, but vacuum is not hot or cold and there a shortage of time involved that could allow anything to become cold. But even if one had hours at 100 km, the equilibrium temperature does not get very cold.
      For instance a sphere of iron [cannon ball] in orbit at 100-200 km is somewhere around freezing Or I would say a 55 gallon oil drum of water probably doesn’t freeze and/or modify it so it can be quite warm or could be below freezing [passively- rather than any active cooling or warming]. One has a cold atmosphere at say 20,000 meter:
      “20000 meter -56.5 C 55 hPa 0.088 kg/m3”
      http://usatoday30.usatoday.com/weather/wstdatmo.htm
      But passing thru it at high speed creates pressure which causes the air
      to be warmer. So being in a balloon floating at 20 km is different to pass thru the region at mach speed. Though if water involved, water can evaporate down to temperatures of near -250 F. But it’s dry up there, or it’s dryness and lack pressure is generally more relevant than temperature.
      A human in spacesuit with a “windscreen” is not going be cold, though if instead were at 1 atm and -250 F a human in spacesuit and windscreen would be cold or cool quickly.

      –How much of the cost of a Falcon 9 is the thin twenty-story-tall aluminum tube, and how much is the complex machinery inside, especially the engines? —
      I would guess the tube about $100,000, and painting it might be significant part of the costs.
      And plumbing, electronics, pumps, flight controls, self destruct mechanism, engines, and etc costs over 10 million. Engines the majority
      of total.

      –Does the internal machinery really go through so much more than on a test firing, because of the “high-altitude winds” etc.?–
      Well we know worked at point landing on the pad. And landing on the pad might have caused some damage.

  2. SpaceX has a business engine that can churn through exploration of different ways of designing the stage for reuse, at low marginal cost. This is not like the Shuttle, where there was the fixed design and no new orbiters coming along (well, except for one, sort of).

      1. Quite. Asking ex-Shuttle people in 2015 to speculate about the refurbishability of the Falcon 9 strikes me as being about as useful as asking former livery stable employees in 1907 what they thought about the maintenance likely to be needed for one of Mr. Ford’s early flivvers.

  3. Well now that $60m cost is back but we don’t know what they include in that cost, how much of that $60m is proprietary distraction, or if there is some miscommunication taking place. I guess the best way to look at this is with a range of estimated manufacturing and refurbishing costs.

    If that $60m is accurate, it is amazing their base price is so close to cost. Didn’t Musk say they were turning a profit? I wonder if they make money off of integration services or if the profits come from inflated NASA contracts.

  4. I’ve always thought that reuse would prove to be more difficult than the gas-it-up-and-go talk we hear from Elon. Sure, that’s the goal, but it’s going to take a while to get there. Orbital rockets have to endure much more stressful conditions than commercial airliners.

    But the only way to find out is to recover stages, then test and/or refly them. Some parts will be fine, while others will be worn out and need refurbishment or replacement. So they will focus on beefing up or redesigning the problematic parts. I’m sure there will be some unexpected “gotchas” along the way, like the DeHavilland Comet in the early 50s.

    Monday’s stage recovery was a major milestone, and the planned static test firing of the recovered stage will be another one. They’re doing great so far. This was only the third time they’ve attempted a landing on a solid surface, in addition to a couple of water landings that apparently went well.

  5. You’ll know they’ve passed the big hurdles when the relaunch the stage without even bothering to clean off all the soot.

  6. I agree with Rand’s premise in the main, though I do feel that there are lessons to be drawn from the Shuttle regarding economic reuse. They are negative indicators; in other words, object lessons in what*not* to do.

    An example of this is the orbiter itself; one of the reasons it took so many man hours (and thus cost) to prep for relaunch was a simple one; access. Simply put, a lot of things were hard to get to. Thus, the shuttle serves as a lesson: design with ease of access in mind, because ease of access cuts down on man hours (and thus cost).

    1. There were some other issues that really cut into their flight rate, too, such as having to reconfigure the payload bay for each launch. SpaceX doesn’t have to do that because they’re not trying to reuse a shroud and all the associated payload mountings, so they don’t have to spend a week removing the ones from the previous mission.

      Another aspect is that NASA couldn’t start turning the Shuttle around until it landed, which was often a week or two after it launched.

  7. This was a fully functional first stage brought back and landed near where it took off after putting its second stage into orbit. This is a monumental achievement and likely to cause a major paradigm shift as it’s no longer necessary to treat rockets like ammunition. The amount of nitpicking going on is indicative of a lot of sore losers.
    Space X is doing it the way it ought to be done – fly, fix and fly again.

  8. What I am surprised by here is how advantageous the strategy of starting expendable and engineering in reuse is looking. Having your customers foot the bill for ~80% of the cost of full-up tests on a monthly tempo, with no contractual expectation of success for the R&D part of the test, is something even a multi-billionaire like Bezos just can’t match. If New Shepard crash lands tomorrow it’s probably another year before another one is ready; if Falcon crash lands the next one rolls of the assembly line a week later. The path to lower cost is not direct, but if every recovery test allows you to innovate something that drops the long-run cost by 1%, and you are running such a test every month, that’s a 45% cost reduction in 5 years. Those can be seemingly trivial changes – new heat shielding, new wear-informed sensor manifests, new brackets to address high-fatigue areas, access changes to make inspection and maintenance easier, launch ops automation, a lighter 2nd stage, a cheaper payload fairing, a methalox 2nd stage.

    As with most true revolutions, from inside this looks more like a series of evolutions punctuated by some PR-worthy moments that are not any more impactful technically or economically than a dozen similar moments that no one paid attention to. As one person on a nasaspaceflight forum said, eventually you won’t be in this business unless you can reuse booster core. The key word being “eventually.” If this really is a revolution, it might be happening slowly enough that by the time the existing players start really executing the advantage is all but gone. Then again, they’ll have lots of SpaceX engineers to hire

    This may change for Blue Origin once they start flying payloads, and hopefully it allows them to accelerate their pace of innovation. However leveraging orbital customers to innovate reuse is definitely an early bird advantage that only SpaceX is currently taking advantage of. The most important flight of the cores becomes when they are retired – because it give an excuse to get old hardware out of the inventory and new hardware in. Really, the longer they can keep some customers insisting on using maiden cores or expendable-sized payloads, the better.

Comments are closed.