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How NASA Steers the Int'l Space Station Around Asteroids & Other Debris

willith writes "I got to sit down with ISS TOPO Flight Controller Josh Parris at the Houston Mission Control Center and talk about how NASA steers all 400 tons of the International Space Station around potential collisions, or 'conjunctions,' in NASA-parlance. The TOPO controller, with assistance from USSTRATCOM's big radars, keeps track of every object that will pass within a 'pizza-box'-shaped 50km x 50km x 4km perimeter around the ISS. Actually moving the station is done with a combination of large control moment gyros and thrusters on both the Zvezda module and visiting vehicles. It's a surprisingly complex operation!"

32 of 44 comments (clear)

  1. surprisingly complex by Anonymous Coward · · Score: 1

    surprisingly complex? im not in the slightest bit surprised - i cant imagine how difficult operations like this would be. the calculations must be staggering...

    1. Re:surprisingly complex by eyenot · · Score: 1

      I might actually be trivial with practice, which is also (as you pointed out) not surprising. None of this is very surprising.

      I'm guessing if you wanted to add a visiting vehicle's thrust, you'd first have to re-calculate the center of mass given the attached vehicle, and then calculate how much thrust -- and in what direction -- from that vehicle will produce what angles of rotation around which axes.

      Not that I could do it all, but I think I might be close, and I can imagine the calculations that go into it and I am, frankly, not at all surprised even in an imaginary sense.

      --
      "Stratigraphically the origin of agriculture and thermonuclear destruction will appear essentially simultaneous" -- Lee
    2. Re:surprisingly complex by eyenot · · Score: 1

      * "I might" / "It might"

      --
      "Stratigraphically the origin of agriculture and thermonuclear destruction will appear essentially simultaneous" -- Lee
    3. Re:Surprisingly complex by SJHillman · · Score: 1, Offtopic

      Well, it's no moon...

    4. Re:Surprisingly complex by nospam007 · · Score: 1, Funny

      "I would have been surprised if it wasn't complex, its a space station"

      Exactly, it's not rocket science.

    5. Re:surprisingly complex by Bazman · · Score: 4, Funny

      Yeah, I mean it's not not rocket science is it?

    6. Re:Surprisingly complex by BenFenner · · Score: 1

      That was my first reaction too. After reading the article, I came away with a different opinion. Apparently there are lots of cats involved, you must be able to read palms, and counting rings in whale teeth is also involved. I won't get into all of the complexity, but I had no idea we were still thatching heat-shields.

  2. "conjunctions" ? by Anonymous Coward · · Score: 1

    Is that because when something gets smashed up there, they say, "BUT it's not our fault!"

    1. Re:"conjunctions" ? by TheCarp · · Score: 1

      http://www.merriam-webster.com/dictionary/conjunction

      1. the act or an instance of conjoining
      2. occurrence together in time or space
      3. b : a configuration in which two celestial bodies have their least apparent separation

      So.... you could say that the paths of an object like the ISS and one of these fist sized bits of junk meeting is.... them occuring at together in time and space; which would make them have the "least apparent separation" (none at all)....and would likely at least partially "conjoin" them (especially if the debris punched through the wall)

      --
      "I opened my eyes, and everything went dark again"
  3. Surprisingly complex by kcbanner · · Score: 4, Insightful

    I would have been surprised if it wasn't complex, its a space station

    --
    Obligatory blog plug: http://www.caseybanner.ca/
  4. Re:Surprising? by jellomizer · · Score: 1

    Yea it couldn't be harder than kSpaceDuel right?

    --
    If something is so important that you feel the need to post it on the internet... It probably isn't that important.
  5. So obvious by GeekWithAKnife · · Score: 1

    They use GPS!

    --
    A 'singular oddity' is an event that cannot be explained and only happens when you are alone.
  6. Asteroids by Megane · · Score: 2

    How NASA Steers the Int'l Space Station Around Asteroids & Other Debris

    If the ISS is anywhere near an asteroid, then Houston, we have a serious problem. (Likewise, if an asteroid is anywhere near LEO, we also have a serious problem.)

    --
    #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
  7. Collision probability threshold levels by 93+Escort+Wagon · · Score: 3, Funny

    One thing the article talks about is the various alert levels assigned to objects in that "pizza box" possessing a non-zero probability of collision with the ISS.

    Yellow: greater than 1 in 100,000
    Red: greater than 1 in 10,000
    Brown: greater than 1 in 2

    --
    #DeleteChrome
    1. Re:Collision probability threshold levels by wonkey_monkey · · Score: 3, Funny

      Brown: greater than 1 in 2

      Brown? Seems a strange colour to choose for impending... oh, got it.

      --
      systemd is Roko's Basilisk.
  8. Hopefully by rossdee · · Score: 1

    no asteroids are going to come as close to the earth as the ISS orbit.

    1. Re:Hopefully by DougOtto · · Score: 1

      It's space junk, not asteroids that present the threat....

      --
      Solving Unix problems since 1989...
  9. Re:Conjunctivitis by aurispector · · Score: 2

    ...and here is a perfect example of why Slashdot is a moribund husk of it's former self.

    --
    I have mod points. The reign of terror begins now.
  10. Not hard at all by DougOtto · · Score: 1

    Sulu: "Z minus 1000m"

    --
    Solving Unix problems since 1989...
  11. asteroids? by snarkh · · Score: 1

    What would an asteroid be doing in a near-Earth orbit?

    1. Re:asteroids? by dpidcoe · · Score: 1

      Maybe NASA put it there and it was a classic case of the governments left hand not knowing what the right hand was doing?

  12. Re:moribund by DougOtto · · Score: 1

    Never use a big word when a diminutive one will suffice.

    --
    Solving Unix problems since 1989...
  13. Pysicists surprized by TheCarp · · Score: 1

    Afterall, the ISS can be assumed to be a frictionless point masss, as can any objects up there. The odds of two point masses colliding is so infinitesmially small as it must never happen, and if it was looking likely, you just model all the thrusters as a single force vector on the sphereical evenly distributed point mass.... simple.

    Sheesh, engineers always make things so complicated.

    --
    "I opened my eyes, and everything went dark again"
    1. Re:Pysicists surprized by TheCarp · · Score: 1

      The only people more suprized by the hubub are the mathematicians... who can't imagine why you would care to continue once you prove that a solution exists.

      --
      "I opened my eyes, and everything went dark again"
  14. hmmm by Nrrqshrr · · Score: 1

    Alright, a stupid question, but what kind of thrusters does the ISS use? Excuse my limited imagination, but when I think of thrusters, I think of an engine burning something to move. Do the ISS's thrusters need constant refueling, in this case?

  15. A blocker perhaps? by azav · · Score: 1

    Can we bring up and roll out a kevlar fabric style large mesh device that will orbit in front of the station at a far enough away distance so as not to obscure the field of view and act as an absorber of some of these floating objects?

    The idea is that it could be unfurled, catch items and when it is degraded enough, it is deorbited and crashes down into an ocean.

    --
    - Zav - Imagine a Beowulf cluster of insensitive clods...
  16. Int'l ... by YoungManKlaus · · Score: 1

    because writing "International" or simply ISS was too mainstream

    1. Re:Int'l ... by Dekker3D · · Score: 1

      Nah, this is a new space station created by Intel!

  17. KSP Trainer by neorush · · Score: 1

    Complex, meh, I've got hours orbiting Kerbals successfully....lets just not talk about the staggering number of dead ones.....pretty amazing when you think about what we're doing up there...and folks wonder why maintaining ISS is so pricey, just think about how many people it takes to edge ISS around something.

    --
    neorush
  18. It's not that complex... by osu-neko · · Score: 1

    Just time accelerate, and things will fly right through each other without damage. ;)

    --
    "Convictions are more dangerous enemies of truth than lies."
  19. Need a tug. by WindBourne · · Score: 1

    Seriously, NASA needs to get a COTS out there for multiple tug/fuel depot. Considering the number of chemical and electric engines, they should be able to get 4 different ones produced. Perhaps allocate 100M or 250M per winner.
    However, to make this useful, they need to use LIDs for the interface. With this approach, it allows docking and berthing. Berthing is a strong connection, which is good for moving things around. Docking is ideal for short term connections, such as to a fuel depot, or a satellite.

    Ideally, with this approach, they could even build a multi-engine approach by simply putting in a base.

    --
    I prefer the "u" in honour as it seems to be missing these days.
  20. they dont have the money ... by YoungManKlaus · · Score: 1

    ... but lets ask google (GSS) ... or Apple (ASS ... how fitting), after all their new HQ will already look like an UFO, maybe it can also fly (who really read all the specs of that thing?)