29 thoughts on “SpaceX’s Reusable Rocket”

  1. I hope they get it to work economically but I won’t be betting on it. It is a two-stage VTVL like the reusable vehicle designs that I think have most promise. But I think it will not be possible to do such a vehicle without redesigning everything for reusability to begin with. Maybe they can get it to work just by tacking on bits and bolts like they have been doing but I doubt it will be economical.

      1. I know they have tested the engines for multiple restarts. That the engines have good thrust to weight ratios. That they use lightweight structures. That now they have working knowledge of heat shields and active control. But I read a lot of literature over a decade ago. I am not a mechanical engineer so its not like I am an expert in this area. Still most designs I can remember were more stubby for several reasons including to save weight and increase vehicle stability. SpaceX designs are not like that. There are historical designs which are more similar to what they are doing like Krafft Ehricke’s NEXUS but even that one used a plug nozzle engine for altitude compensation. I guess that was a SSTO vehicle so maybe the difference in Isp isn’t as problematic. After all you will have different nozzles for the 1st and 2nd stages in SpaceXs vehicles. Still I wouldn’t be surprised if they had to go for a completely different vehicle design and the Raptor staged combustion engine to get reusability to work. I thought their last attempts did not work because the vehicle got burned on reentry and crashed in the ocean?

        I still haven’t seen anyone solve the controlled reentry problem in a satisfactory and economic way. Heck even for all the faults SpaceShipOne had at least Burt Rutan came up with a novel way to soften up reentry and cheap spray on heat shield protection. Which probably would not work on a vehicle that goes to orbit but at least the idea was interesting.

        1. SpaceX entered the stage successfully on the last flight ISS flight. They hope to recover it on the next one. They do it by sacrificing payload performance.

    2. That’s the genius of SpaceX. They’ve ALREADY redesigned EVERYTHING for reusability. That’s the Falcon 9 v1.1. It’s reusable down to its bones (a perfect example being the TEA/TEB igniters), it was designed for it. The genius is that they made it a duel use vehicle. It can be reusable with only one major modification (addition of legs) or it can be used in an expendable flight and thrown away. Which means that it’s already got 3 flights worth of operational experience proving it to be a capable stage. And also means they can test out reusability aspects on some flights without affecting the main payload delivery (which they will have done on half of v1.1 flights after the next flight).

      Moreover, because the Falcon 9 is such a simple rocket and most of the cost is in the 1st stage these simple reusability steps have the biggest bang for the buck.

      1. Indeed impressive that the Falcon 9 v1.1 is both tough enough and with enough performance margin that recovery and reuse is a plausible option, and cheap enough to build to beat competition as an expendable.

  2. The math seems to work out, but it’s interesting how much it’s necessary to start with reusability as an option. SpaceX is uniquely able to tackle reusability because so much of their engineering is in house, because their rocket is a simple design, and especially because the first stage (the easiest to reuse) is the most expensive stage. Hopefully it’ll usher in a new rocket design trend which will lead to lots of reusable rockets, but it might take some big shakeups from the established rocket companies.

  3. I saw an analysis that indicated a Falcon 9 v1.1 first stage with legs and a Dragon capsule was probably marginally SSTO.

  4. It strikes me that if SpaceX is about to pull it off (and they will do it this time or the next..though I would be happiest if they do it this time!), they will alter not only the launch market but the payload one as well. Multiple cheap launches mean that satellites will become cheaper over time, as it will become increasingly practical to launch lots of smaller, less capable ones than one ‘big bang’, This has huge implications for system reliability as well as further depressing costs (economies of scale, etc.) which could establish a virtuous cycle.

    1. SpaceX President/COO Shotwell has stated that reusable Falcon 9 prices could end up around $5-7 million. That’s pretty aggressive and would depend on improved manufacturing efficiencies of the 2nd stage, most likely, but it’s not out of the realm of reasonableness. And that’s delivering something like 5+ tonnes to LEO. That changes the entire landscape of spaceflight for damned sure, especially if they can achieve a high flight rate. And if they can achieve the same thing with a reusable Falcon Heavy, which would have a 20+ tonne payload and should be priced less than $20 million, then who knows what’s possible. It’s fascinating to think that for the cost of a single SLS launch it could conceivably be possible to launch 100 reusable Falcon Heavies.

      1. The two ‘booster’ F9s of a FH should just immediately become ‘recoverable’ one a regular F9 is recoverable. The second stage (if the payload isn’t completely maxxed out) would seem easier to maneuver for a stable orbit than reenter. (And, I’d be ecstatic to have 100 of them bolted together in orbit, even if there isn’t a plan yet.)

        But that center first stage is going to be both high and fast. It seems like a more difficult recovery problem than the others.

        But that’s -still- a massive, immediate price reduction.

        1. Worst case scenario you ditch cross-feed and just bring all 3 1st stage cores back at about the same time. It would be a big hit to performance but the cost savings would be so immense it would probably be worth it.

          Also, the scenario where you have an expendable Falcon 9 (a sub $60 mil rocket) with two 1st stage cores as reusable boosters (in theory sub $5 mil each) is pretty fascinating too. It means you get D4H LEO payload capacity at nearly Falcon 9 prices, which is still impossible to compete with even if they throw away 1/3 of the first stages every flight.

    2. “………………..as it will become increasingly practical to launch lots of smaller, less capable ones than one ‘big bang’, ”

      Which, I would think, would help promote the create of orbital refueling infrastructure. It takes some serious smash to get to the planets

    3. f1n0nacc1 – It strikes me that if SpaceX is about to pull it off (and they will do it this time or the next..though I would be happiest if they do it this time!), they will alter not only the launch market but the payload one as well.

      This concept is the one that came immediately to mind when I read Foust’s assertion in the article: “It’s worth noting,” he says, “that many current customers of launch services, including operators of commercial satellites, aren’t particularly price sensitive, so thus aren’t counting on reusability to lower costs.”

      It continues to amaze me that people can look at a market and decide that a “lack of pricing options ” is the same as a “lack of price sensitivity”. I’m happy to see that people still exist who believe that lower-priced options will change the market rather than be stifled by it.

  5. As an aside, it would be interesting (probably only to me), how Musk put together such an innovative team. As far as I know, Musk is not a rocket scientist. All the great ideas they’ve effected could not have all come from him – or maybe any for that matter.

    So how did he build this organization?

    THAT, to me, is the genius of Space-X

  6. I met Elon Musk when he was starting his space business. He came to Stanford where I was teaching to look for the best students we had. He went looking for the best and he is smart enough to recognise the best. I think you need to credit Elon for lots of smarts.

        1. wow. Just wow.
          you pick some REAL winners there.
          Fkynn?

          You do realize that tesla did not cost taxpayers anything. Yes?
          The money that SpaceX has received from NASA for COTS (299 m) has saved NASA MORE THAN THAT ALREADY. Had ULA been doing this, it would cost 320-380 million PER FLIGHT. And that does not include the capsule, etc.
          SpaceX is charging 120M for EVERYTHING.
          So, with 3 flights, they have saved over 600 million.

          Now, we have CCdev, in which they have the opportunity to get around 540 million. They are current at around 440 million.
          BUT, SpaceX is within 12 months of having a full human launch system. At that point, they can launch 7 ppl for less than what Russia charges us for 2. Most importantly, we can count on it without politics interfering.

          Yet, Flynn says nothing about it.
          The man is a joke. His hatred of Obama allows him to do nothing but bash everybody associated with him.
          Sad man.

        1. LOL.
          All through this, he claims that Elon was in the right place at the right time. IOW, he was lucky. In the end, he claims that Telsa is a pump/dump.

          You know what I call that? Sour grapes from somebody that does not have a grasp of how companies work. Without knowing exactly who this is, I can tell you that he is nothing more than a stock trader, who does not have a grasp of what is involved in start-ups, let alone companies.

          THis guy is a JOKE.

  7. As the price of launching sats gets cheaper, and in relative terms REALLY cheaper, will not the sats themselves also become cheaper? If you are only losing 5-7 million for a failed launch, versus 100 million it stands to reason you will beable to much easier eat the loss of the sat as well if you design it a lot cheaper and just replace the failed sat with a cheap replacement on a cheap launch, instead of designing it forever because the launch costs are so extremely high.

    thoughts?

    1. There are actually some fascinating economics at play with regard to the satellite market. The prime example being the Iridium satellites. Because the initial constellation was so large and put up so fast they switched to an assembly line system for building them, and in doing so were able to cut per satellite costs down to nearly 1/10th of conventional manufacturing techniques. I think that’s interesting in regards to cheap access to space because it implies that the difference between launching 10 satellites a year at circa $100 million a launch and launching 100-1000 satellites a year at circa $10 million a launch isn’t necessarily that the cheaper satellites are actually lower quality, just built using different processes.

    2. In a sense, you’re describing how the Soviet military handled space back in the 1980s. They had a wide set of boosters and were doing about 60 launches per year. Their satellites were comparatively crude and short lived but inexpensive because they were built in large numbers. I remember reading a classified report back in 1986 or early 1987 about how they handled a launch failure. Instead of grounding the booster for an extended period of engineering navel gazing, they simply took the next satellite and booster in the pipeline and launched them two weeks later.

      GEO comsats aren’t as likely to benefit from vastly lower launch costs because of the limited number of orbital slots available. That factor encourages larger satellites with more transponders to provide greater bandwidth per slot. The lower costs can encourage all electric satellites like the Boeing 702SP that trade time for greatly reduced launch costs. Boeing says that the US government has bought three satellites based on that bus but isn’t saying who the customer is or the nature of the payload.

      1. There’s at least one potential benefit for GEO, and that’s cheaper orbital construction. If you can launch up crews to do assembly, or rely on a space infrastructure for tugs and such, you can assemble much larger satellite platforms than any rocket (even a Saturn IV) could launch in one go. Think about football-field sized structures, or dishes in the 10+ meter range.

  8. Going from a $50M to a $7M Falcon 9 would be nice especially if the payload is still the same. As for sparking a huge increase in demand, going from $20M per seat for NASA to $3M per seat might increase the number of orbital visitors paying commercial rates from 1 to 50 per year. The interesting possibility is settlement of Earth orbit, the Moon or Mars. For that to convert into launch, someone (probably Musk) needs to get into the space settlement business.

    2. To elaborate on Rand’s comment, the price varies with the cargo.

      What will be interesting to see, is the price of launching NASA astronauts and then compare that with the price of launching people for other clients.

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