Crew Dragon

Its solar panels are generating much more power than expected.

Well, that’s nice.

[Tuesday-morning update]

NASA is very happy with the Crew Dragon performance so far.

Meanwhile, SpaceX is moving from stage-production mode to fleet-management mode.

Only four cores doesn’t seem like enough to me. One of the reasons we retired Shuttle was that we had too small a fleet with only three. But SpaceX can build more.


20 thoughts on “Crew Dragon”

  1. I don’t know how much it matters. My understanding is, in addition to DM-2, USCV-1 and CRS-21, USCV-2 will also be a Dragon 2, with Starliner CFT now scaled back to a 2 month flight between the Dragon Crew-1 departure in March and Dragon Crew-2 arrival in June, with USCV-3 Starliner “Calypso” not arriving before November 2021 (and pending full success of OFT-2 and CFT). Maybe a manufacturing aid by allowing the CRS Cargo Dragons (one in 2020 and two in 2021) to use the cheaper, less capable colar cells? Maybe the short Axiom flight in late 2021 could use them as well, or the Space Adventures non-ISS flight? Just guessing.

    1. As I recall, there were some concerns over solar cell degradation, because the solar cells on this mission’s trunk (DM-2 was originally planned to be quite short) were not rated for long duration – thus concerns that they would degrade during a long mission.

      So, producing more power than expected means that, so far, the solar cells aren’t degrading anywhere near as fast as feared. At this rate, these cheaper solar cells might just get approved for full duration crew missions.

      1. Ok that makes sense, starting at a higher capacity means they won’t degrade to the minimum required as quickly. Is there any word yet on what the observed degradation rate is so far?

      2. What’s different about these solar panels is that the cells are the same as on the narrow strip on my TI-36X calculator, only there are lots and lots of those tiny strips assembled into a panel.

        Every other spacecraft manufacturer is using much larger cells, of which there are many fewer to a panel. Only some say that Mr. Must is way, way ahead of the competing spacecraft because he bought out this German company that automated to process of attaching many, many tiny solar cell strips to a panel.

          1. Mr. Must is the lack of an editing function to replace a “t” with a “k” after selecting Post Comment.

            The remark about the TI-36X solar cells is a “riff” off the Tesla battery packs assembled from multitudes of laptop computer cells that I suppose just plain sat there, drained of any charge.

          2. Elon Musk’s evil bearded counterpart from an alternate universe. Some say that Elon Musk is only one lab accident away from becoming a super villain. That would be cool.

          3. Elon is the evil, bearded person in our universe, where his alternate-universe counterpart is actually decent and nice in a corny, old-fashioned way.

            This is much like the Seinfeld episode where each member of the Seinfeld gang turns out to have a counterpart among another circle of friends who are polite to each other but much less hip, edgy and interesting.

    1. Probably not designed for that. However, if they have a design that works better than expected for long durations, then maybe the ISS itself can get an upgrade on a future launch. That would be a great payload for a cargo Starship.

      1. I don’t think ISS will need an upgrade before 2030 (and splash). It’ll be interesting to see if Axiom and OPSEK come to fruition. I’d hoped for a Bigelow station too, but it seems to be fading away.

        If, for some reason, you did need to replace the ISS arrays, it’d be tough to do without Starship, since it took 4 Shuttle flights to get them up there in the first place, but I thought of a way. You could mount each replacement array to the external payload trunions of a Dragon XL and launch to LEO aboard a Falcon Heavy with the planned extended fairing. I’m not sure where you’d stick the old ones while doing the swap out.

        I also think if Heavy is going to be in use for a while, it’d be worth USG’s while to pay for an upgrade to LC-40, so it could handle Heavies. It used to be a Titan III pad, so it shouldn’t be impossible. And right now 39A seems like a risky choke point, as its the only Heavy and Crew Dragon pad.

        1. Bigelow’s biggest contribution to inflatable technology will be in training (and then laying-off) the engineers that end up actually end up developing the first serious inflatable modules for SNC and possibly Boeing.

  2. I’m not sure reuse is “now” essential. It seems like for SpaceX, reuse has always been essential. That matters, because on this blog, it has been pointed out that this reuse is what drives launch costs down. And driving launch costs down is essential to opening up space for all of us.

    I agree that more cores would be best, but that seems like Berger’s point. SpaceX needs reuse out of its current cores in order to meet their 2nd half flight goals, which he then clarifies the title that reuse is now critical. This is yet one more paradigm shift that has been expected. Reuse is now expected and necessary.

    Finally, there seems to be 4 cores ready for flight and then 5 others, which includes the core used for DM-2 plus 4 other cores that flew earlier this month. There is no reason to expect those 5 recently flown cores need much more than to complete post-flight inspection and whatever level of refurbishment SpaceX performs on them. 9 launch boosters is quite a stable.

    1. Yeah, it’s always been essential and production is part of fleet management. Who knows how many times a F9 can be reused but they need to keep making new ones to keep people sharp, make changes, and replenish spent cores.

      1. And, as we saw twice this year, sometimes the landing attempt isn’t successful. They have to factor in unexpected recovery failures into their required fleet size.

  3. Generically speaking, Hawthorne can manufacture up to 400 Merlins a year (some unknown mix of 1Ds and Vacs), enough for forty complete Falcon 9s, or 13 and a fraction Heavies. I guess the thing to forecast would be the mix of upper stages, first stages, cores, and strap-on boosters (and noting that first stages and strap-on boosters are interconvertible). I’d bet on ten new first stages/cores/boosters a year and count on an average of 5 flights each, the equivalent of 50 new expendable rockets a year, suggesting 50 upper stages with vacs, and 90 1Ds a year. That seems to leave 260 Merlins a year going into stockpile, until the pile is big enough.

  4. Next year bids fair to be the beginning of an exciting new era in space, finally transending the heady days of Gemini, Apollo, and Skylab, when it seemed possible we really might have spinning space stations, moon bases, and set off for Jupiter by 2001.

    It’s possible there will be nine crewed space flights next year (4 Crew Dragons, three Soyuz, and two Starliner). Throw in the likely first (uncewed) flight of Starship and maybe even the first (uncrewed) Artemis flight, and maybe we will see a return to the Moon and a first human landing on Mars in the next 5 years or so.

    In 1969, I thought perhaps I’d die on Mars some time in the future. Not likely anymore, unless I win some kind of ‘Die On Mars” contest in the next few years (I’m almost 70 now), but at least it’s not completely impossible…

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