back to article SpaceX Falcon tests hovercraft tech – despite ISS outage

NASA has said that SpaceX's latest cargoship launch to the International Space Station will go ahead, despite a critical computer outage on the station, allowing the firm to test the craft's hovering abilities. Mounting landing legs (~60 ft span) to Falcon 9 for next month's Space Station servicing flight pic.twitter.com/ …

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  1. cookieMonster Silver badge

    KickSat also on board

    best of luck to @zacination with #Kicksat - Fly baby, fly….. Launch is T-Minus 9:50 min ...

  2. ratfox

    Soft landing on the ocean

    Are they so unsure about ending in the right place? Otherwise, why not do it on the ground in the middle of the desert? Even if it ends up exploding, it seems a better simulation…

    And if they are really unsure about controlling the rocket, it seems hardly worth it to add legs to it, considering the only thing they plan to do is to hover gently above the ocean before sinking it.

    1. James Hughes 1

      Re: Soft landing on the ocean

      They have already done many hover tests with Grasshopper - what they really need is a test with all systems in place. There are plenty of aerodynamic issues that are affected by the legs, so yes, it needs them on there to be a representative test.

      As for landing in a desert - possible, but much much safer to test at sea. To get to a desert, you probably have to overfly something that you probably don't want to land on by accident. And the sea is much bigger so harder to miss.

      With rockets, its always best to err on the safe side.

    2. Irongut

      Re: Soft landing on the ocean

      The legs add mass and if they are not fitted exactly symmetrically they may throw off the centre of mass. There may also be aerodynamic considerations. Having them fitted will make the test more useful.

    3. heenow

      Re: Soft landing on the ocean

      To rendezvous with the ISS, you must launch into its west-to-east orbit, which in the U.S. means from the east coast to avoid launching over people. The launch vehicle will be many miles out to sea at separation, and has to fly back to land, something that has not been thoroughly tested yet. So they'll "soft land" it on the water and then try to recover it. The shuttle's SRBs were lowered by parachute into the ocean, and then recovered and reused for decades.

      The goal is to have Falcon's recovery systems reliable and accurate enough to fly back to sparsely populated coastal areas and land softly enough to be reused. This is just the first operational test of that goal.

      1. PC Paul

        Re: Soft landing on the ocean

        If it was me I'd be tempted to have a barge or flat-decked cargo ship in place at the expected landing area, then if the approach was going well tell it to land there - otherwise you could choose/be forced to miss and land it in the sea anyway.

        Seawater and complex systems are a bad mixture, why dunk it if you can help it?

        1. Tom 13

          Re: I'd be tempted to have a barge or flat-decked cargo ship

          I wouldn't. Same problems you have landing a fighter jet on a carrier: the deck is constantly in motion. That complicates the landing way beyond the test parameters. Sea water may be bad, but a busted ship and a busted barge are even worse. And that's your likely outcome. Plus, you may still have to deal with sea water anyway.

        2. I. Aproveofitspendingonspecificprojects

          Re: Soft landing on the planet

          "why dunk it if you can help it"

          Not disagreeing with you but if you can't land it safe on earth where can you land it safely?

          I can't see why Russia is set on going to the moon for its next project nor any of the stupid things the Chinese have been doing just because they can.

          Why don't the lot of them get together and work on doing something they can't, much nearer home?

          War easier to maintain than peace, is it?

      2. James Micallef Silver badge

        Re: Soft landing on the ocean

        "The launch vehicle will be many miles out to sea at separation, and has to fly back to land"

        Surely having the launch vehicle 'fly back to land' will require more fuel plus some guidance systems, that's lots of exra cost. If taking off west to east from Florida, why not buy up an area in another country to land the rockets in? The first available landmass east of Florida is Sahara desert, plenty of sparsely populated wasteland that could be bought on the cheap.

        1. James Hughes 1

          Re: Soft landing on the ocean

          Then you have to add the cost of getting the rocket back to the launch pad....might as well take the hit up front and fly back.

          1. James Micallef Silver badge

            Re: Soft landing on the ocean

            "Then you have to add the cost of getting the rocket back to the launch pad....might as well take the hit up front and fly back."

            It's not only monetary cost though, it's also cost of fuel/range of the rocket itself. If you land east of the Atlantic and have to ship the rocket back, the overall cost in both fuel and $$ will be higher, BUT you're spending the extra fuel on the surface and get to have more payload on the rocket

    4. cray74

      Re: Soft landing on the ocean

      "Are they so unsure about ending in the right place? "

      Not really. They're worried about it staying under control as it falls, like the last Falcon 9 (September '13) landing mishap. The falling first stage went into a roll beyond the ability of its thrusters to control and tumbled to the water. Hitting the bullseye was less of a concern, since SpaceX's aim was pretty good by that point.

      "Otherwise, why not do it on the ground in the middle of the desert?"

      Because this rocket launch is to service the International Space Station under contract from NASA, and thus this Falcon 9 needs to launch from Florida to keep SpaceX's customer happy. Other than some metaphorical moral deserts in Miami and Orlando, Florida doesn't really have a desert for rocket testing. However, Florida does have a lot of test range infrastructure and Snark Infested Waters that have been receiving test rockets for decades. Beyond keeping its paying customer happy, SpaceX is piggybacking this launch to try out landing hardware and protocols, but that's purely secondary. Get stuff to the ISS first, play Harrier second.

      Further, SpaceX is paying attention to rocket design history. The first bits of rocket hardware rarely work as planned even after hundreds of tests in the lab. Rather than trying to get all the widgets and gizmos to work right on just the second try, SpaceX is only testing a limited number of features (thus minimizing variables) on this flight. The flight in September failed for a reason. SpaceX'd like to make sure that reason is solved and try out a few new things. Actually getting everything to work for landing is going a bit too far, and they've got a Grasshopper to test reusable flight (in a desert, in fact).

      "considering the only thing they plan to do is to hover gently above the ocean before sinking it."

      Considering that hasn't been accomplished previously, that's not an "only thing." The last time SpaceX tried that the rocket went into an uncontrolled roll and crashed. (Also into the ocean, since the paying customer wanted a launch from California into a polar orbit.) And despite that, SpaceX was very happy with the September flight. It gave them mountains of information about real world aerodynamics of rocket stages falling arse-first from space and important lessons about residual fuel behavior. (The crash was caused by fuel 'whirlpooling' in the fuel tanks.)

      It might not seem like much to have a rocket land vertically on telescoping legs, but that's actually an achievement involving a huge amount of engineering addressing thousands of problems in a handful of test flights. That's quite different than testing a new car airplane design, where you can fly or drive the vehicle thousands of times before beginning to sell them. You're condensing a lot of mistakes into a few flights, and crashes are to be expected.

  3. WonkoTheSane
    Mushroom

    Launch streaming live on Space.com @ 19:45GMT

    Hope that doesn't happen! ----->

  4. phuzz Silver badge
    Boffin

    If you pop here and put in your details:

    http://spotthestation.nasa.gov/sightings/

    You can find out if/when you get a chance at spotting Dragon flying over, for example we should be able to see it at about 22:20 BST in the UK tonight.

  5. Parax

    will eventually make for precise set-downs on the surface of alien worlds

    Ermmm Not quite right.. whilst they do hope to get to foreign worlds the falcon 9 launch stage never will.. it will never be Falcon 9 legs on alien soil, maybe Dragon paws will make it though...

  6. Vladimir Plouzhnikov

    At last!

    A rocket only becomes a proper space rocket when it has legs and can land on its tail.

    But... a really, really good space rocket also must have big fins. Where are the fins?

    1. Steven 1
      Alert

      Re: At last!

      And if it has fins it absolutely has to have LASERS!!!

    2. hplasm
      Happy

      Re: At last!

      And a checkered band- it needs a checkered band, just below the nose cone!

      1. Thecowking

        Re: At last!

        Ideally it should launch from a swimming pool, for security reasons.

    3. Anonymous Coward
      Anonymous Coward

      Re: At last!

      "Where are the fins?"

      They get burned off when the motor gimbals to the side...

    4. I. Aproveofitspendingonspecificprojects

      Where are the fins?

      Lap land?

      1. I. Aproveofitspendingonspecificprojects

        Re: Where are the fins?

        That Professor Goddard with his chair at Clark College doesn't know of the relationof action and reaction and the need to have something better than a vacuum to push against.

        http://astronauticsnow.com/blazingthetrail/gruntman_btt_pages/gruntman_blazingthetrail_p_117.pdf

        Bollocks too to the Registers timeline for an edit. You bastards.

  7. Daniel B.

    ohoh

    Nice to see reuseable stuff being tested. I've always thought that one-use rockets are a stupid waste of money. At least the Space Shuttle was mostly reused sans the fuel tank...

    1. Tom 13

      Re: ohoh

      Resources maybe, money is quite often a wash. Remember it frequently costs more to fix things than to make them from scratch these days. And I say that as someone who'd really rather fix than replace in most instances.

      1. James Hughes 1

        Re: ohoh

        That was certainly the case with the Space shuttle. Cost a bloody fortune to get it ready for the next flight.

        Estimated cost of the F9 reusable 9 engined first stage is $30M or I believe. Don't have to reuse it many times to get your money's worth (and you can afford to replace an engine or two). And it only carries about $150K worth of fuel....

        Expected turnaround is a LOT faster than something like the shuttle.

      2. Steve Knox

        Re: ohoh

        Resources maybe, money is quite often a wash. Remember it frequently costs more to fix things than to make them from scratch these days. And I say that as someone who'd really rather fix than replace in most instances.

        Since the only long-term value of money is as a proxy for finite resources, this says more about the weaknesses of our economic systems than it does about the validity of the reuse philosophy.

    2. WonkoTheSane

      Re: ohoh

      Until the US pork machine got involved, the shuttle was intended to be air-launched from a manned mothership, in much the same way as Virgin Galactic are planning.

      1. John Smith 19 Gold badge
        Unhappy

        Re: ohoh

        "Until the US pork machine got involved, the shuttle was intended to be air-launched from a manned mothership, in much the same way as Virgin Galactic are planning."

        No. what screwed the STS design was the Office of Management & Budget's requirement that no yearly expenditure exceed $1Bn. IE not enough for 2 different stages.

        That budget profile is completely unlike any real space (or indeed large infrastructure) investment programme.

        With only enough money to develop 1 complete new stage and engine the design was one of only (possibly) 2 that could be afforded.

        All the other designs went in the trash with that funding profile.

  8. John Smith 19 Gold badge
    Boffin

    MDM is not a computer

    The top level MDM's have IIRC on board 386'x (but they might have had an upgrade).

    Otherwise Multiplexer/DeMultiplexers collect data or receive commands through a pair of network links and route them appropriately. I think they have some kind of internal filtering and caching functions but they don't actually have an on board processor.

  9. imanidiot Silver badge

    Mission got scrubbed for today

    Unfortunately it was just announced a technical issue was encountered (no further elaboration so far) and the launch was scrubbed for today. They're venting/draining propellants now.

    1. wilber

      Re: Mission got scrubbed for today

      Their site states that it was because of a Helium leak in the first stage.

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