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Space Technology

Elon Musk Talks "X-Wing" Fins For Reusable Rockets, Seafaring Spaceport Drones 96

An anonymous reader writes Elon Musk sent a number of tweets recently in which he detailed a program to test the function of "X-Wing" style grid fins that could help spacecraft navigate upon re-entry. The tweets describing how it would work, also include an autonomous seafaring platform, which can hold its position within three meters even in a heavy storm, that would act as a landing pad. From the article: "The SpaceX reusable rocket program has been progressing with varying results, including an explosion over Texas back in August. While the incident didn't result in any injury or even 'near injuries,' Musk conceded in a tweet that this was evidence that '[r]ockets are tricky.' An earlier test flight from this summer involving an ocean splashdown was considered more successful, proving that the Space X Falcon 9 booster could re-enter earth's atmosphere, restart its engines, deploy its landing legs and make a touch down at 'near zero velocity.'"
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Elon Musk Talks "X-Wing" Fins For Reusable Rockets, Seafaring Spaceport Drones

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  • by Dunbal ( 464142 ) * on Sunday November 23, 2014 @04:18PM (#48445273)
    I've seen these already in use on bombs and other ordnance from several factions.
  • Elon Musk isn't just daydreaming, those are product announcements. It would have taken NASA 15 years and billions in contracts to create a reusable booster, it would have crashed more often than Musk's prototype and ended up costing more on a per-launch basis than one-shot boosters. NASA is why we can't make big steps into space.

    The proof of that statement will be when Musk comes sailing in with a reclaimed booster in tow.

    • No. Its not NASA, its Boeing, Lockheed Martin, et al.

      When people talk about the "privatization of space" I generally laugh. Spacecraft where always made by private industry, and always operated by the government, so far nothing has changed.

      Why else did the space shuttler look like an airplane? Thats not a practicle design for space. Its because it was made by boeing.

      Its just that SpaceX is not a defense contractor.

      • the orbiter was designed to not only take thing into space but to return them. With the thought being instead of wasting money by letting it burn up in atmosphere by brining it back down for repair/ upgrades.

        I have said many times before the last shuttle mission to the hubble shouldn't have been maintenance but to box it back up and bring it home. The Orbiter is the only space craft designed to due something like that.

        Instead we waste billions on letting valuable tech burn back up and clutter up the orbit

        • by 0123456 ( 636235 )

          Instead we waste billions on letting valuable tech burn back up and clutter up the orbits with garbage.

          It's only valuable if you can reuse it. Hubble would probably have cost less if you just mass-produced them and launched another one every few years, rather than trying to repair the existing one; it only made sense if NASA could actually reach its original, highly optimistic, launch cost forecasts.

          • Actually, that was the case of Hubble. NASA paid for the first one, and the second generation of it went to NRO.
        • Hidden history. The original intent of the Space Shuttle was for both civilian/NASA and US Air Force use [wikipedia.org].

          The crucial factor in the size and shape of the Shuttle orbiter was the requirement that it be able to accommodate the largest planned commercial and military satellites, and have over 1,000 mile cross-range recovery range to meet the requirement for classified USAF missions for a once-around abort from a launch to a polar orbit. The militarily specified 1,085 nm cross range requirement was one of the pr

          • The USAF wanted to launch heavier satellites to higher orbits than the Shuttle could do. After the Challenger disaster and the cancellation of the Shuttle-Centaur the USAF and NRO had no other choice but to use the Titan rocket, which was really expensive, to launch these payloads. Things like reconnaissance satellites and things like that.

            • by doom ( 14564 )
              The way this argument goes is that the shuttle would've been able to take lighter payloads to a higher orbit, but the USAF design contraints screwed that up. So we got a shuttle-to-LEO when all the action (the satellites it was supposed to service) were up in GEO.
          • The bit I like:

            Q: "Why did they use segmented SRBs?"
            A: Because Morton-Thiokol is in Utah, without a sea-port, and the pieces had to fit on trains or trucks.

            Q: So why didn't they go with a company that did have ocean access, like Aerojet in Sacramento? A: James Feltcher was from Utah.

          • you do realize even with both accidents the orbiter had a lower death rate compared to soyuz right?

            That is the number of people killed compared to launched. of course the difference is a fraction of a percent.

      • by bledri ( 1283728 ) on Sunday November 23, 2014 @10:12PM (#48446667)

        No. Its not NASA, its Boeing, Lockheed Martin, et al.

        When people talk about the "privatization of space" I generally laugh. Spacecraft where always made by private industry, and always operated by the government, so far nothing has changed.

        Why else did the space shuttler look like an airplane? Thats not a practicle design for space. Its because it was made by boeing.

        Its just that SpaceX is not a defense contractor.

        No, the big difference is how the contracts are written, how the winners are selected, and how much design influence NASA and Congress exert (yes Congress).

        Historically, NASA was heavily involved in the design and many decisions were forced on them by Congress to direct the money to specific congressional districts (remember those segmented solid boosters on the Shuttle? You can thank Congress for them. And they are going to use them again on the next generation SLS which is not a commercial contract.) Historically, once NASA/Congress have doled out the contracts, the work was performed on a cost plus basis. The contractors had very little financial risk, and NASA/Congress had a lot of control over the process.

        The way a commercial contract works is that the companies bidding on the contracts are given requirements and they have much more freedom in how they meet those requirements. They respond with a proposal as to how they intend to provide a solution and a fixed cost. SpaceX builds almost everything in house, Orbital Sciences outsources almost everything in their rocket. Both choose exactly how they wanted to meet the requirements and NASA/Congress had no control over them which allowed them to take very different approaches.

        Ideally, more than one company wins a commercial contract (SpaceX and Orbital for cargo, SpaceX and Boeing for crew). This provides redundancy in case there is a failure, unlike when the shuttle failed and our entire manned space program was grounded for years. Twice. It also allows for more competition to put some downward pressure on prices and allows for new entrants for future contracts.

        Now system is perfect, but the commercial cargo/crew program is absolutely better than how we used to handle "routine" space requirements.

      • by Teancum ( 67324 )

        The point about private spaceflight isn't who is building the spacecraft but rather who is footing the bills and owns the equipment afterward.

        And no, spacecraft are not always operated by the government. In the past, it was companies like Boeing and Grumman who would build the vehicles, but it would be NASA employees who would fly them, fuel them, and take care of everything else once it left the factory. That started to change a little bit in the 1980's when the Reagan administration started to encourage

    • NASA doesn't build rockets. They write contracts for companies to build rockets. The reason SpaceX is building rockets today is thanks to previous developments due to NASA contracts and current NASA procurement.

    • NASA is why we can't make big steps into space.

      NASA still makes great strides in space, it's just not in the "logistics" business anymore. Their focus is on gathering the most data from the most places, not just about how to build rockets. And for that goal, their transportation needs are pretty generic. Whoever can deliver the most cargo on orbit, on time, at the lowest price will get the job.

      What sets Elon apart is his unilateral will to act, combined with the resources to take action at a grand scale. Call it the Tony Stark Effect... SpaceX is the on

      • Mostly a great post, but to be fair, Elon did NOT have the resources. He invested only about a 100 million into this. Basically, he started this with less money than Boeing, L-Mart and ULA spend on lobbying each year.
        So no, it was not having massive resources. It was just smart investments and not thinking about this like an MBA.
        • Your point is well made, but I think it's a case of semantics. Elon had "enough" resources to get the job done, with help from others. If he hadn't put $100M of his own money into SpaceX nobody else would have put in $100K, let alone the millions more it took to get where they are today. The fact that even Elon occasionally needs help from others doesn't strike me as a particularly important criticism.

    • It is not NASA's fault. It is congress going after pork. The scientists at NASA are pretty damn good and generally know what they want. Often it is a choice between something misguided like SLS or nothing at all. It is not as if NASA scientists or administrators would have picked SLS the way it is. They were pretty much told, if you don't build it using these suppliers we are not going to fund you.

    • Sigh; (Score:4, Insightful)

      by WindBourne ( 631190 ) on Sunday November 23, 2014 @08:23PM (#48446283) Journal
      I should mod you down, but I have to speak up.
      First off, Musk had this in mind back in 2002 when he started this. IOW, he has 12 years into it.
      Secondly, Musk HAS SPENT BILLIONS on this. Some of his money. Some of others. Some of NASA. Some of future contracts. All in all, he has spent billions to get to this point.
      Third, NASA builds prototypes, but all of the rest is done by private companies, otherwise known as PRIVATE SPACE.

      Chad, what I find interesting is that ALL OF NEW PRIVATE SPACE will tell you that they NEED NASA. Why? Because NASA knows this stuff inside and out. Heck, Elon did F1 on his own all the way through to his first launch. Remember how that turned out? SPECTACULAR.
      After that, he swallowed his pride and worked closely with NASA and their QA. And while F1 underwent a re-design, what really changed was that SpaceX learned how to do decent QA. They put into place repeatable processes.

      So, while you can continue to knock SpaceX, bear in mind that Musk, top ppl from SpaceX, Bigelow, top ppl from BA, Bezos, top ppl from BO, Ozmen, top ppl of SNC, will all tell you that they cound heavily on NASA. And they will tell you that they count on NASA for experience and help far more, than on their money.

      It is long past time to put aside your politics and focus on facts.
  • I thought the ultimate goal was to have the 1st and 2nd stages return to launchpad on their own. That would've been cool, but I guess they decided it was too hard.

    An autonomous barge and precision landing would still be a lot cheaper than deploying a dozen US Navy ships and thousands of sailors looking for a capsule.

    • That would've been cool, but I guess they decided it was too hard.

      I have not seen any evidence that the second stage has ever been designed to soft land. I believe the issue about land touchdown is get approval to do so. I bet few government bodies trust the technology that much. Sure there have been a few short flights that have touched down on land but that is very different than a post-reentry touchdows. The problem being that if something goes wrong a hundred kelometers up the rocket stage could land in a populated area.

      An autonomous barge and precision landing would still be a lot cheaper than deploying a dozen US Navy ships and thousands of sailors looking for a capsule.

      Any Dragon capsule will still splash down in the

      • by 0123456 ( 636235 )

        I have not seen any evidence that the second stage has ever been designed to soft land.

        There are SpaceX videos showing it doing just that, though the big saving comes from reusing the first stage, which has nine times as many engines as the second stage. If you can reuse the first stage ten times, then reusing the second starts to make sense, because it would make up around half the cost of a launch.

        Any Dragon capsule will still splash down in the ocean.

        For now. Again, the plan appears to be to switch to a powered landing on land, as the same engines can then be used for launch abort, in-flight maneuver, and landing.

        • There are SpaceX videos showing it doing just that,

          Care to reference anything showing that? All the videos I can find are of first stage touchdowns. Do you see any landing legs on the second stage?

          Again, the plan appears to be to switch to a powered landing on land,

          The Dragon 2, the personnel carrying version, is planned to have a powered landing but the Dragon 1, the cargo version, is not. The difference is payload weight. The Dragon 2 will have a much smaller payload than Dragon 1. Dragon 2 will also be much more expensive as it must include life support. Remember, every pound that you us in fuel to bring the capsule to gr

          • by 0123456 ( 636235 )

            Care to reference anything showing that? All the videos I can find are of first stage touchdowns.

            Actually, looks like the specific video I was thinking of isn't an official SpaceX video:

            http://www.youtube.com/watch?v... [youtube.com]

            Do you see any landing legs on the second stage?

            The first stage didn't have landing legs until it needed them, either. Ultimately, you have to start recovering the second stage if you want to dramatically cut costs, because replacing it soon becomes the major cost in the launch once you start reusing the first.

            • Current thinking is that the second stage is probably not easily reusable, and they are not actually working on it.
              Those videos were produced at a tim when there wasn't a concrete idea as to how flyback would work in practice.

              • Perhaps not, but every launch is an opportunity to test aspects of a potential recovery system. Testing ideas, gathering data, etc. I'd be kind of surprised if they didn't at least turn their eye toward experimenting a bit now that they seem to have gotten the basic launch mechanism worked out. After all right now it's just dropped in the ocean - if you could even just get it to do a controlled glide to a desired location you could potentially make at least a small profit by delivering the hulks to Europe

                • The second stage, for many launches - to GEO - ends up in an orbit which is very unfriendly to reentry - if it reenters, it will do at a very high speed.
                  This makes reentry not simple.

                  • Yes, and I would not expect such launches to realistically attempt a return until the "easy" launches were being returned consistently. But conceptually at least, speed is a problem easily fixed by grazing the upper atmosphere a few times to get down to "normal" reentry speeds.

                    In fact though, a collection of large high-strength metal cylinders seems like it could be a valuable asset in orbit - perhaps rather than deorbitting them we could have them synchronize orbits and anchor to each other. Bind them in

                    • Grazing the atmosphere has issues.
                      The heating pulse is quite large, and radiating it to cool down again before the next encounter may be an issue.
                      Plus, it places strong demands on the attitude control, and heats the tanks a lot when they're still full of volatile fuel.
                      'Just' reentering normally from what will be at least LEO takes quite a lot of heatshield or reaction mass.

                    • Yes, it's definitely not a simple problem to solve, which is exactly why I would expect them to take the opportunity to test potential solutions whenever possible. For example - there's no reason there needs to be any fuel left in the tanks: by the time you've hit the atmosphere you're pretty much done with the rocketry stage of your journey - choose your reentry point carefully and you can rely on aerobraking and gliding for the rest of the journey to the salvage yard. Only after you're confident with yo

            • It is official. Or was. I remember Gwynne Shotwell or Elon Musk using it in a presentation.

      • The current F9 second stage is not designed to be reusable, although there are plans to redesign it to do so. However, that will be done after the first stage reuse is regularly functioning, and they currently have nothing to show.

        Dragon V2 is planned to land on, well, land. It has legs for just that reason, along with beefed-up maneuvering thrusters to serve double-duty as descent rockets.

      • Any Dragon capsule will still splash down in the ocean. The barge will be used to land the, now fuel empty, first stage rocket.

        For now, you are right.
        For the first powered landing of the Dragon2 from space, I am guessing that Musk will use the barge.

    • by 0123456 ( 636235 )

      I thought the ultimate goal was to have the 1st and 2nd stages return to launchpad on their own. That would've been cool, but I guess they decided it was too hard.

      That is the ultimate goal. In the meantime, they need to recover the stages in a location where they won't kill people if something goes wrong, and verify that they are reusable after recovery (e.g. no serious damage that would cost more to fix than building another stage).

      SpaceX's whole program has been about making incremental steps, rather than trying to jump to a reusable launcher in one go. The fundamental problem with most previous attempts to build reusable launchers is that they require billions of

    • They're doing this because they don't want to delay their landing trials until they get cleared to fly the stage back to the launchpad.

      Basically they don't know how long it'll take for the government to issue a permit (and the government probably doesn't know either).

  • Grid fins are stowed on ascent and then deploy on reentry for "x-wing" style control.

    X-Wings fly like planes in an atmosphere (come to think of it, they fly like planes in space too). They don't drop vertically and use the wings to steer. So, what's this got to do with X-Wings?

    • by 0123456 ( 636235 )

      So, what's this got to do with X-Wings?

      Uh, there's four of them? Like, in an X?

    • So, what's this got to do with X-Wings?

      Because X-Wings are associated with the future and are cool. Being associated with a cool future is a great PR move. This seems to me to be the an indication that Musk is going more for style than content.

      What to X-Wings have to do with the actual technology used? Nothing.

    • The shape of an X when all 4 are deployed.

    • I was hoping for blasters and proton torpedoes.
  • Can some aerospace engineer enlighten me about the advantage of these tennis-racket shaped x-wings over some standard steerable fins which you see e.g. on a guided missile? I could imagine that the grid-shaped 'louvers' could be seen as many small fins in parallel, but intuitively I would think that one big fin would have more effect. Is it something related to hyper-sonic aerodynamics? Or is it mechanically stronger?
    • I am not an aerospace engineer but there is an obvious advantage; drag. Normally drag is a bad thing but when you are trying to slow the decent of an object drag is a very good thing. The more drag they can produce the easier it will be to slow the decent.

    • (Also) Not a aerospace engineer, but steerable fins often require some pretty complex navigation hardware/software, they can often be subject to some unexpected aerodynamic forces (stall, angle of attack, flow separation, etc). A few "tennis-racket shaped x-wings" are a nearly foolproof method of slowing and righting a underpowered cylindrical body to a desired orientation. For bombs that would be nose down, for a reusable VTVL rocket that would be rockets down so the "tennis-rackets" would be placed near

      • No, the 'x wings' are not passive, but they are just as steerable as normal fins. See this video of SpaceX [youtube.com] where they used them for roll control on a test flight in Texas. And the software to control these is pretty standard.
        • "No, the 'x wings' are not passive"
          Neat, never seen airbrakes used in such a way (the article only showed a picture). But I still think my previous statement is not too far off the mark. They would be partially extended after "reentry" to help slow the stage, and perhaps used to help steer the stage towards the landing pad. Then as seen in the video they would be used to help control orientation to the pad and aid in deceleration. Standard fins wouldn't be able to do all of these at once and would be su

        • Ha, all those cows were like "Shit, not again!! CHEESE IT!"

        • Here is a twitter discussion [twitter.com] with Musk and Carmak that gives some reasons for using the fins. To quote:

          Elon Musk @elonmusk Nov 22

          Testing operation of hypersonic grid fins (x-wing config) going on next flight pic.twitter.com/O1tMSIXxsT

          Elon Musk @elonmusk Nov 22

          Grid fins are stowed on ascent and then deploy on reentry for "x-wing" style control. Each fin moves independently for pitch/yaw/roll.

          John Carmack @ID_AA_Carmack Nov 22

          @elonmusk Good luck. We had supersonic control inversion issues with actuated fins, went back to little thrusters that worked at all speeds.

          Elon MuskVerified account @elonmusk

          @ID_AA_Carmack No choice. Entry velocity too high for a precision landing with N2 thrusters alone. Must have aero surfaces for pitch trim.

          My suspicion is that there will be a degree of unpredictability for this flight as they refine the control characteristics of these fins. Thus Musk was quoted as saying that the success probability was 50/50 for this landing.

  • Importance (Score:4, Interesting)

    by Jodka ( 520060 ) on Sunday November 23, 2014 @05:10PM (#48445461)

    There is a great interview with Elon Musk on youtube here [youtube.com]. He is remarkably transparent about his reasoning. One key to his success is that he works very hard to understand motive and purpose when making decisions.

    Musk makes that point that it costs about as much to fuel a rocket as it does to fuel a 747. Space launches are mostly so expensive because the vehicle is sacrificed with each launch, not because of the energy requirements for a space launch. The other big component of the expense is that rocket manufacturers charge a lot. According to Musk the value of the raw materials from which they are formed is reasonably inexpensive. Those were two hugely important realizations because they meant that space launches were not inherently expensive and therefore there is enormous potential for reducing launch costs.

    By being Space X instead of Boeing the cost of launch is reduced to about 25% of conventional launches because Space X can assemble a rocket from raw materials for that much less. A re-usable vehicle, Musk predicts, would reduce launch costs by an order of magnitude.

    So those are the motives and reasoning underlying the X-wing grid fins and re-entry discussed in the Slashdot summary.

    • by Greyfox ( 87712 )
      Yah, you can build a rocket out of any ol pipe, really. If you want a reasonable guarantee that it won't explode the moment you turn it on, it'll cost a good bit more.
    • Those were two hugely important realizations because they meant that space launches were not inherently expensive and therefore there is enormous potential for reducing launch costs.

      I'd be impressed by the first of these realizations (part of the expense being due to throwing the rocket away) - if it hadn't been common knowledge before Musk was even born. That's the whole reason why NASA kicked off what eventually became the Shuttle program around the same time they kicked off the (original, earth orbiter

    • There is a great interview with Elon Musk on youtube here [youtube.com]. He is remarkably transparent about his reasoning. One key to his success is that he works very hard to understand motive and purpose when making decisions.

      Musk makes that point that it costs about as much to fuel a rocket as it does to fuel a 747. Space launches are mostly so expensive because the vehicle is sacrificed with each launch, not because of the energy requirements for a space launch. The other big component of the expense is that rocket manufacturers charge a lot. According to Musk the value of the raw materials from which they are formed is reasonably inexpensive. Those were two hugely important realizations because they meant that space launches were not inherently expensive and therefore there is enormous potential for reducing launch costs.

      By being Space X instead of Boeing the cost of launch is reduced to about 25% of conventional launches because Space X can assemble a rocket from raw materials for that much less. A re-usable vehicle, Musk predicts, would reduce launch costs by an order of magnitude.

      So those are the motives and reasoning underlying the X-wing grid fins and re-entry discussed in the Slashdot summary.

      Very well said.

      BTW, I wish every CEO were like Musk - it would make for a saner company, for researchers and engineers.

  • All hail Elon Musk, he's like the Bennet Haselton of the real world!

  • The real reason that the Tesla X is behind in development is the logical cross product from SpaceX of turning those falcon doors into real wings:
    The Tesla flying electric car... Woot!

  • Disney Corporation announces a lawsuit with SpaceX over the use of the word "x-wing" in a recent tweet describing his new rocket spacefins.
  • The tweets describing how it would work, also include an autonomous seafaring platform, which can hold its position within three meters even in a heavy storm, that would act as a landing pad.

    I'm sure that Musk is aware of it, but there is a DP (Dynamic Positioning) spacecraft launch system [wikipedia.org] which has been operating with reasonable success (~90%) for 15 years now. The DP systems (which are pretty routine in deep-water oil exploration equipment these days - anchors don't work well below about a half-kilometre

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