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

Soulskill posted about a year ago | from the get-out-and-push dept.

ISS 44

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!"

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Surprising? (0)

Anonymous Coward | about a year ago | (#44193835)

I don't really see how it's surprising that it's a complex operation to maneuver 400 tons of material, hurtling around the Earth ~8km/s, past various debris that may be no bigger than my fist.

Re:Surprising? (1)

jellomizer (103300) | about a year ago | (#44193939)

Yea it couldn't be harder than kSpaceDuel right?

surprisingly complex (1)

Anonymous Coward | about a year ago | (#44193847)

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

Re:surprisingly complex (1)

eyenot (102141) | about a year ago | (#44193863)

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.

Re:surprisingly complex (1)

eyenot (102141) | about a year ago | (#44193873)

* "I might" / "It might"

Re:surprisingly complex (4, Funny)

Bazman (4849) | about a year ago | (#44194369)

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

"conjunctions" ? (1)

Anonymous Coward | about a year ago | (#44193881)

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

Re:"conjunctions" ? (1)

TheCarp (96830) | about a year ago | (#44193997)

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

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)

ANd, or... (0)

Anonymous Coward | about a year ago | (#44194051)

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

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)

...and it's not our (NASA's) fault!

See, it works with 'and' too.

Letr's try 'or'...

"It was either space debris or the Chinese doing anti satellite weapons testing."

Yep, works with 'or' too.

Is there ANY conjunction that it doesn't work with?

Surprisingly complex (4, Insightful)

kcbanner (929309) | about a year ago | (#44193883)

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

Re:Surprisingly complex (1, Offtopic)

SJHillman (1966756) | about a year ago | (#44193931)

Well, it's no moon...

Re:Surprisingly complex (1, Funny)

nospam007 (722110) | about a year ago | (#44194027)

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

Exactly, it's not rocket science.

Re:Surprisingly complex (0)

Anonymous Coward | about a year ago | (#44194493)

TFS was talking about the operation. Not the station.
The station can be complex. The operation doesn't have to.

Re:Surprisingly complex (0)

Anonymous Coward | about a year ago | (#44195517)

Are you kidding me? It's a man-made space station that weights 450000kg orbiting around Earth. The original poster was saying that he's not surprised the operation is complex given what's involved (The ISS).

I can't tell if you're really an imbecile or if you're trolling.

Re:Surprisingly complex (1)

BenFenner (981342) | about a year ago | (#44195657)

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.

So obvious (1)

GeekWithAKnife (2717871) | about a year ago | (#44193947)

They use GPS!

Re:So obvious (0)

Anonymous Coward | about a year ago | (#44194005)

They don't need GPS, everyone knows that open space is EMPTY.

duh'

Re:So obvious (0)

Anonymous Coward | about a year ago | (#44196171)

They probably do. Many satellites are tracked using GPS. I wouldn't be surprised if the ISS had GPS. Of course, you can't use GPS for space debris.

Conjunctivitis (0)

Anonymous Coward | about a year ago | (#44194001)

Let's just hope the ISS never experiences conjunctivitis! Hahahaha. I'll be here all day.

Re:Conjunctivitis (2)

aurispector (530273) | about a year ago | (#44194205)

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

Re:moribund (1)

Doug Otto (2821601) | about a year ago | (#44194637)

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

Asteroids (2)

Megane (129182) | about a year ago | (#44194003)

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

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

Collision probability threshold levels (3, Funny)

93 Escort Wagon (326346) | about a year ago | (#44194091)

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

Re:Collision probability threshold levels (3, Funny)

wonkey_monkey (2592601) | about a year ago | (#44194219)

Brown: greater than 1 in 2

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

Hopefully (1)

rossdee (243626) | about a year ago | (#44194153)

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

Re:Hopefully (1)

Doug Otto (2821601) | about a year ago | (#44194287)

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

Re:Hopefully (0)

Anonymous Coward | about a year ago | (#44214419)

Except of course for those that do fall on earth in a daily basis, are small, fast, and do a hell of a lot of damage if they hit something. Usually they burn up in atmosphere cause they are small in size, but their speed is in the order of 5000-25000 km / sec.
You do understand that if something hits you at that speed it's size really doesn't matter. A 500g tennis ball sized asteroid traveling at 5000 km/sec posses 1,250,000 Joules of energy. This is about 2400 times more energetic than a bullet fired by a 9mm pistol. I guess nobody would like to get hit by that :D
One consideration is how probable it is to get hit from something like that in about 400km from the surface of the earth (about where ISS flies, and where MIR used to fly). Well, this is a big discussion. But, there are "experimental" evidence that point out the probability:
Take a peek at MIR's solar panels after some years in orbit: http://www.sciencephoto.com/image/337978/350wm/S6350053-Damage_to_the_Mir_space_station_s_Spektr_module-SPL.jpg

Not hard at all (1)

Doug Otto (2821601) | about a year ago | (#44194283)

Sulu: "Z minus 1000m"

asteroids? (1)

snarkh (118018) | about a year ago | (#44194319)

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

Re:asteroids? (1)

dpidcoe (2606549) | about a year ago | (#44194827)

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

Pysicists surprized (1)

TheCarp (96830) | about a year ago | (#44194991)

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.

Re:Pysicists surprized (0)

Anonymous Coward | about a year ago | (#44195271)

So that's what they meant about the sperial cow jumping over the moon...

Re:Pysicists surprized (1)

TheCarp (96830) | about a year ago | (#44195723)

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.

hmmm (1)

Nrrqshrr (1879148) | about a year ago | (#44195255)

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?

Re:hmmm (0)

Anonymous Coward | about a year ago | (#44195999)

Yes. Read about it: https://en.wikipedia.org/wiki/ISS_Propulsion_Module

Mario (0)

Anonymous Coward | about a year ago | (#44195481)

Don't just hit the "jump" button,eh?

A blocker perhaps? (1)

azav (469988) | about a year ago | (#44196261)

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.

Re:A blocker perhaps? (0)

Anonymous Coward | about a year ago | (#44198583)

1 - ISS could get hit from any direction - though a hit from an object overtaking it (ie. hitting it from behind) would be rare. Most objects in the lower part of LEO where ISS resides have relatively low eccentricity, or they'd have decayed already. So if they're nearly circular and cross ISS's altitude, then they're traveling at about the same speed, so not likely to overtake it. But crosstrack events are very common - so putting a shield "in front of the station" isn't going to do all that much good.

2. No large deployable shield that we could hope to launch come anywhere close to absorbing the type of impacts in question.

Int'l ... (1)

YoungManKlaus (2773165) | about a year ago | (#44197915)

because writing "International" or simply ISS was too mainstream

Re:Int'l ... (1)

Dekker3D (989692) | about a year ago | (#44202229)

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

they dont have the money ... (1)

YoungManKlaus (2773165) | about a year ago | (#44204197)

... 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?)

KSP Trainer (1)

neorush (1103917) | about a year ago | (#44198175)

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.

It's not that complex... (1)

osu-neko (2604) | about a year ago | (#44198625)

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

Need a tug. (1)

WindBourne (631190) | about a year ago | (#44199065)

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.
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