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Spaceflight Formation Flying Test Bed Takes Off 64

Posted by Soulskill
from the enemy's-gate-is-down dept.
coondoggie writes "Getting complicated systems onboard a single spacecraft to operate as one integrated unit can be hard enough, but some space agencies are trying to address the challenges of getting multiple spacecraft to fly in formation and operate together as one unit. Such challenges are exactly what a new European Space Agency lab in the Netherlands is set to address. The test bed addresses crucial operational factors for formation flying, including mission and vehicle management, guidance navigation, dealing with faults and communicating between satellites."
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Spaceflight Formation Flying Test Bed Takes Off

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  • by FullBandwidth (1445095) on Friday September 10, 2010 @05:14PM (#33539950)
    Their most recent direction has a decidedly "open source" feel to it ... and you still have a chance to submit proposals: http://www.darpa.mil/news/2010/SystemF6NewsRelease.pdf [darpa.mil]
  • Traveling in formation is essential if you want multiple spacecraft to travel together. It's not like airplanes which can each have a pilot at the controls. Automatic formation will be absolutely necessary to avoid collisions.

    But I want to berate the author of TFA, because the issue is traveling in formation, not "flying". Spacecraft do not "fly". I'm not nitpicking; there is a pretty big difference. It's just plain intellectual laziness on his part.
    • Man, you must just about have an anurism every time you read "space flight".

      Bottom line,. people will use the term fly. get use to it.

      • Bottom line: people will cheat you in your life, too. Get used to it.

        If it's wrong, why should I just "get used to it"? What, you don't think setting things right is worthwhile?
        • by geekoid (135745)

          It's not wrong. however;

          Because we are talking about a common use of a common word being used in the commons. Not in scientific literature. It does no harm, and causes no confusion. It's not being used to 'teach the controversy' .
          It's like spazzing over the term 'hacker'.

          "What, you don't think setting things right is worthwhile?"
          tsk, tsk. Seriously? you jump to a logical fallacy? I've read your posts, you're smarter then that.

          In THIS case, if you don't 'get used to it' you will spend a lot of time frustrat

        • Do arrows fly?

          Do stones?

          I think most people agree that they do when they are thrown, even though they may have no propulsion and no aerodynamic lift.

          How is this different to what spacecraft do?

          It isn't. They are all examples of ballistic flight.

    • by starless (60879)

      Spacecraft do not "fly". I'm not nitpicking; there is a pretty big difference. It's just plain intellectual laziness on his part.

      No. This is a standard term. Please check before criticizing others if you don't know the field.
      See e.g.
      http://dst.jpl.nasa.gov/

    • by AJWM (19027) on Friday September 10, 2010 @05:43PM (#33540314) Homepage

      Spacecraft do not "fly". I'm not nitpicking; there is a pretty big difference. It's just plain intellectual laziness on his part.

      Nope, ignorance on yours. Spacecraft do indeed fly. Flying has nothing to do with wings or aerodynamic forces, it has to do with moving without touching the ground. There are certainly other terms for how spacecraft move -- which depend on the particular spacecraft and what they're doing -- but even pure ballistic flight (aka "orbit") is still flight.

      • by geekoid (135745)

        what do you expect from a girl~

        zing! or maybe BA-ZING~

      • So when swimming under water, you're actually flying under water?
        • Re: (Score:3, Insightful)

          by Sulphur (1548251)

          So when swimming under water, you're actually flying under water?

          Especially Penguins fly under water.

          • by JustOK (667959)

            Especially Penguins fly under water.

            in theory. There's no mathematical proof that penguins exist..

          • by AikonMGB (1013995)

            Well, if you believe that planes fly through the air, then what is different about water? Air and water are both fluids, they just have different densities. Think of a submarine -- it has control surfaces just like an airplane.

            The term "flight" is widely used in the space industry, regardless of how appropriate the original meaning was at describing the motion of spacecraft and satellites (recall that early rockets didn't even make it to orbit, but still passed the edge of "space").

            Aikon-

        • by geekoid (135745)

          In a lot of respects..yes.

        • by AJWM (19027)

          Water could be considered really, really soft ground, so not necessarily. But as another poster observed, what penguins do underwater is more like flying than anything else.

        • Since I first learned to swim, I've always felt that moving around in a 3D environment under water is similar to flying.

          Snorkeling on a reef is _very_ similar imho.

          Terje

      • Okay, I will concede that in the dictionary I consulted, that use was indeed listed... in the 5th meaning of the word. The first is still "to move through the air using wings."
        • by ErkDemon (1202789)
          Well, if we're going to be picky, if you check what your dictionary defines as a "wing", you'll probably find that the corresponding first definition is something to do with the flappy things on birds. Dictionary.com doesn't mention the "aeronautical" definition of "wing" until definition #9, so by the argument you used, we probably shouldn't call what aircraft do "flying", either, because their "wings" aren't biological structures, and don't flap.

          AFAIK, "spaceflight" is pretty much the standard term for

          • "a surface used to produce lift for flight through the atmosphere - or occasionally through another gaseous or fluid substance." was the first defn on google search for 'wing'.
        • by AJWM (19027)

          Okay, I will concede that in the dictionary I consulted, that use was indeed listed... in the 5th meaning of the word.

          Doesn't matter whether it was the 5th, the 1st, or the 97th, it invalidated your statement that "Spacecraft to not 'fly'". If you're going to accuse somebody of intellectual laziness, you'd better have done your homework yourself.

    • by ErkDemon (1202789)
      "Traveling" is too vague. Spacecraft "travel" when you trundle them to the launchpad on trucks, and if we're doing astrometrics, motion is relative and the concept of whether something is "traveling" or not becomes complex. You're "travelling" right now as the Earth orbits the Sun.

      If we want a term to describe orderly controlled non-surface relative motion through a rarefied medium, "flight" isn't bad, "fly" has the advantage of only being one syllable, and we already have the concepts of "powered" and "u

    • Poor intellectual judgement on his part? It's the accepted term. Just look at
      http://spaceflight.nasa.gov/home/index.html [nasa.gov], and the about 1,430,000 other results just at nasa.gov pages.

    • From wikipedia: [wikipedia.org]

      Flight is the process by which an object moves either through the air, or movement beyond earth's atmosphere (as in the case of spaceflight), by generating lift, propulsive thrust or aerostatically using buoyancy, or by simple ballistic movement.
      • by ZygnuX (1365897)
        "Or by simple ballistic movement" That means that people can fly unaided, for very short amounts of time?
    • good point. however, it makes me wonder how applicable the recent software which mimics how birds and fish travel in flocks/schools will be to this problem
  • At first glance all I can think of is Serta Sleepers being thrown into space.

    Liftoff! We have liftoff of Stainy One, ushering in America's new in-orbit dumping of unwanted mattresses. Next month will see the launch of Smelly Two.
  • One way they can address this is with indiscernible warnings from fellow pilots [youtube.com].
  • arguably are not relevant in space...or at least i fail to see the relevance from any standpoint other than purely tactical. The only thing spacecraft require
    is an understanding of eachothers location, and an understanding of the location of objects around them. a significantly well developed computer program
    would certainly be capable of tracking this information

    it just shouldnt be capable of singing daisy.
    • Re: (Score:3, Insightful)

      by geekoid (135745)

      it's incredibly complex, and will be needed for robotic swarms. Imagine trying to keep 1000 robots in formation with each other without have an unexpected event start to cascade thought the swarm and cause a formation collapse.

      • Re: (Score:3, Interesting)

        by cynyr (703126)

        why do they need to be in tight formation? a voltron style bot? well i guess something like each bot has a mirror, and they are making a huge telescope, but i fail to see how thats better than just using a rigid structure in the first place. bolt it together so it can be put together by 6 bots, and then taken back down the same way, and be hauled "up" in pieces.

        • Increasing the distance between mirrors increases the effective radius, while decreasing the distance increases the light collection capabilities. A cluster may want to do either depending on what it's trying to image.
          • Increasing the distance between mirrors increases the effective radius

            Yes.

            while decreasing the distance increases the light collection capabilities.

            What makes you think that?

        • but i fail to see how thats better than just using a rigid structure in the first place.

          Rigid structures are massive.

          bolt it together so it can be put together by 6 bots, and then taken back down the same way, and be hauled "up" in pieces.

          Many heavy and therefor very expensive pieces. Much, much, much cheaper to use ion engines, laser interferometers, and clever software to maintain relative position.

    • Re:formations (Score:5, Informative)

      by butalearner (1235200) on Friday September 10, 2010 @06:55PM (#33541030)

      [Formations] arguably are not relevant in space...or at least i fail to see the relevance from any standpoint other than purely tactical. The only thing spacecraft require is an understanding of eachothers location, and an understanding of the location of objects around them. a significantly well developed computer program would certainly be capable of tracking this information

      Disregarding the fairly major difficulty of accurately determining the location of objects around them (not to mention the nontrivial bit of understanding its own location), they also need to have an understanding of the velocity and acceleration as well. In space, moving in one direction doesn't mean what you think it means. If one accelerates in the direction of motion, it will take longer to orbit the Earth. If two satellites at the same altitude are traveling parallel to each other in the same direction, they will collide in 1/4th of an orbit. There's a reason that there was a spacecraft recently whose sole purpose was to demonstrate autonomous rendezvous.

      If that still sounds simple, now add a dozen satellites, and realize you can't just make them fly in the same formation all the time. The fuel requirements for stationkeeping of the outermost satellites would be astronomical. You have to minimize course corrections if you want a reasonable mission lifetime. Or carry a great deal of fuel, which can easily defeat the purpose of using smaller spacecraft in the first place. On top of that, when you need to apply collision avoidance maneuvers, you have to make sure you don't put yourself onto a collision course with the other 10 satellites.

      As for the purpose of formation flying (note we're talking about the cluster kind - the trailing formations are fairly straightforward):
      Wikipedia [wikipedia.org]

  • Spaceflight Formation Flying Test Bed... wait wasn't that a Pink Floyd album cover?

  • Wasn't this solved in Galaga?
  • Um, wasn't that the purpose of the Gemini missions? To prove and define the concept of 2 or more spacecraft flying in formation (and docking)?
    And later unmanned Progress craft flying in formation, and docking with, the ISS.
  • I suddenly had a image of rockets being attached to a bunk bed and being launched. Am the only one that got this image?
  • Flying Test Bed Takes Off - giving a whole new meaning to the mile high club.

    Sorry couldn't be bothered to RTFS

  • The article unfortunately contains almost no information, except for the fact that ESA wants to do formation flying and is developing some testbed. This is not news, since ESA has been studying missions involving satellites flying in close formation for more than 10 years: for example the Darwin mission [esa.int], which would have flown some telescopes at a few hundred meters to do optical aperture synthesis for detecting extra-solar planets (mission appears to be shelved right now) and XEUS [esa.int] which is a 'standard' 100

    • by Morty (32057)

      NASA has a number of Earth-observing satellites already in orbit that do formation flying as part of the so-called "A-Train". TFA mentions this, although it links to a PDF instead of HTML. See:

          http://en.wikipedia.org/wiki/A-train_(satellite_constellation) [wikipedia.org]

      • by photonic (584757)
        That is probably not the same kind of formation flying as TFA was talking about. At 690 km altitude, the A-train has an orbital velocity of 7.5 km/s, so the minimum separation of 15 seconds translates to more than 100 km of mutual distance. Although this is not really trivial to do and would probably require some daily adjustments of the orbits, it is more like 'flying several satellites in the same orbit', totally controlled from the ground. The missions I was mentioning operate within 1 km of each other a
  • by b4upoo (166390) on Friday September 10, 2010 @07:23PM (#33541240)

    Apparently I must be dumb as a rock as it would seem to me that several jets flying information have the same problem as satellites traveling together. Speed, position and collision avoidance seem to be old issues to me. I wonder if the government actually farmed out money to grow a solution? Am I a dummy or what goes here?

    • by Moridin42 (219670)

      Jets flying in formation have their own organic computers that require offline maintanence roughly every 18 hours. Spacecraft don't have the luxury of landing to let their pilots off, or for hauling months of food, or the means to keep their pilots from going insane with the monotony. Not if they're going to be financially feasible anyway. Hence.. automated systems for maneuvering and analyzing sibling craft position, as well as getting physically discrete systems to interoperate as a single platform.

    • Re: (Score:3, Interesting)

      by wagnerrp (1305589)
      Aircraft have aerodynamic control surfaces to maneuver, spacecraft must do everything with reaction thrust. Not only do you have a limited amount of fuel, of which you cannot get more, but you have to worry about dousing others in the formation with your exhaust. Formation flight is generally for the purpose of some sort of phased array telescope, and you don't want to gunk up your optics with rocket fuel.
      • Actually, apart from reaction thrust you can use a 2nd way of manoeuvring in LEO orbit: adjusting your drag parameters.

        Satellites in LEO still experience some drag from the outer layers of the atmosphere (this is why they decay if the orbit is not maintained by manoeuvres).

        In theory, you can use that to adjust your orbit (e.g. by adjusting the attitude of the satellite so a larger surface points forward: or by temporarily increasing that forward facing surface, e.g. with adjustable or inflattable panels
  • Since they are not using propulsion once they obtain an orbit, would it not be more realistic to call them "formation falling"?

    Just a thought...

    • by wagnerrp (1305589)
      A satellite without propulsion is a dead satellite. LEO satellites require fuel for occasional boosts to prevent reentry. GEO satellites require fuel or else they will drift off station. Everything needs some reserve to push it out of the way once its functional life is up, and let other satellites take its place.
  • My ex wife did a stint at nasa on this very subject, using controls theory or whatever
  • The US Navy has quite some experience (decades, actually) with formation flying with their NOSS (Naval Ocean Surveillance System) SIGINT satellites ( http://www.satobs.org/noss.html [satobs.org]). The old one flew in tight triangular formations of three (quite a sight to see), the newer ones do it with two. They serve to pinpoint ships based on their radio communications.

    Also, the Chinese appear to be experimenting with a similar concept (http://www.nasaspaceflight.com/2010/08/china-launches-military-satellite-yaogan-w [nasaspaceflight.com]
  • Since before the moon missions, we have docked ships. I think that is multiple ships flying "in formation". Don't seem to understand the expense...
  • It's getting the "pew! pew! pew!" noises to sync up that's hard.

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