Pentagon eyes crash analysis on 1,300 satellites

Reuters ^ | 11/03/2009 | Andrea Shalal-Esa

[ErnstStavroBlofeld]

The U.S. military said on Tuesday it is now tracking 800 maneuverable satellites on a daily basis for possible collisions and expects to add 500 more non-maneuvering satellites by year's end.

The U.S. Air Force began upgrading its ability to predict possible collisions in space after a dead Russian military communications satellite and a commercial U.S. satellite owned by Iridium collided on Feb. 10.

General Kevin Chilton, commander of U.S. Strategic Command, called the collision the "seminal event" in the satellite industry during the past year and said it destroyed any sense that space was so vast that collisions were highly improbable.

He said military officials had wanted to do more thorough analysis of possible collisions in space, but had lacked the resources. Before the collision, he said they were tracking less than 100 satellites a day.

"It's amazing what one collision will do to the resource spigot," he told a space conference in Omaha, Nebraska.

The crash, which was not predicted by the U.S. military or private tracking groups, underscored the vulnerability of U.S. satellites, which are used for a huge array of military and civilian purposes.

Chilton said the Air Force was tracking more than 20,000 satellites, spent rocket stages and other objects in space, up from just 14,000 a few years ago.

But he said that was just what U.S. could "see" and there were estimates that the actual number was much greater, posing a potential threat to satellites on orbit.

Air Force Lieutenant General Larry James, who heads U.S. Strategic Command's Joint Functional Component Command for Space, told reporters the Air Force met its goal for tracking possible collisions among 800 satellites that have the ability to be moved in September, ahead of an October target date.

[ErnstStavroBlofeld]

Space Junk locations

[D-fendr]

[D-fendr]

Sorry about the double photo.

I don’t see how there’s room for anything else up there..

[ErnstStavroBlofeld]

No problem about the double photo. The biggest problem to any manned program is space junk. It has also become a national security issue.

[Berlin_Freeper]

As Two Ships Passing in the Night

As two ships passing in the night,
So quietly neath the stars soft light;
Our paths cross but now and then.
Reaching out, seeking one another again.

We say hello and then we part,
Knowing we’ve shared a piece of our heart.
Some friendships stay and sadly some go.
My prayers remain steady hoping ours will grow.

I ache when you’re hurting,
I cry when you’re sad.
Wanting to comfort and hold you so bad.
Know that I’m waiting here, with open arms,
To share all your troubles and relish your charms.

I have nothing to offer but the soul of a friend,
Strong shoulders to lean on that don’t easily bend.
I offer these freely with no strings attached,
For in caring and sharing you’ll not meet my match.

So on some long and lonely night
When nothing seems to go just right
Close your eyes and think of me,
Under the moon’s glow is where I’ll be.

[Dumpster Baby]

That will put your eye out.

[TomasUSMC]

after a dead Russian military communications satellite and a commercial U.S. satellite owned by Iridium collided on Feb. 10.

/////
More to that one that meets the eye

[topsail]

An excellent opportunity for some entrepreneur to start the first space junk recovery/recycle collection route. There must be billions of dollars floating around up there, just waiting to become money in someones pocket.

There must be a market for selling the technology that could be recovered from a competitor’s space vehicles, if for nothing more than to show technology progression. Why is the shuttle returning empty ?

It will become a reality someday. Why not now, there is no competition

[Lonesome in Massachussets]

The crash, which was not predicted by the U.S. military or private tracking groups,

I find this surprising. Specifically surprising. After the collision, I downloaded the last unclassified OES for both satellites prior to the collision and propagated them using SGP4, the model they are designed to work with. The model showed that they would pass within 70 meters of one another. Iridium is maneuverable, and supposedly maneuvers whenever there is a prediction that they will pass within 5 km (5000 meters) of another satellite. It is possible that they only check once a week or so and the OES came out within about 24 hours of event. The problem of collision avoidance is N-squared, the complexity goes as the square of the number of satellites, since I only had to check two satellites my problem was N-squared simpler. Still Iridium LLC only needs to worry about their 66 (maybe 65 now) satellites times a few thousand others.

Yes, someone paid me to do it.

[1776 Reborn]

I wonder if this space junk inhibits UFO’s too. They probably call Earth “Junker One”.

[Condor51]

If two satellites orbiting earth up in the vacuum of space crash together, does it make any noise?

[raybbr]

An excellent opportunity for some entrepreneur to start the first space junk recovery/recycle collection route. There must be billions of dollars floating around up there, just waiting to become money in someones pocket.

Surely, you jest. What value does decades old technology have?

[SoftwareEngineer]

Please do keep in mind that many analysts believe that the Iridium “incident” was a space war move. Take it for what it is worth, but a significant portion of analysts believe that this was a test to show how satellites could be knocked out of orbit WITHOUT an anti satellite missile launch

I can’t say any more at this point

[Lonesome in Massachussets]

Like I said, the collision was “predictable” in the sense that the unclassified OES available prior to the collision had the satellites passing within 70 meters of one another. There is no established accuracy for OES and predictions. You can see celestrak.com for a discussion. Actual accuracy varies by satellite and celestrak.com and other users try to characterize the accuracy by evaluating how well older OES predict newer ones. Space Command’s position is that the OES are checked continually as observations become available, but if the new observations agree with the predictions of current OES within 5 km, no new OES are issued. They violated this rule after the Iridium-Kosmos collision by *reissuing* identical OES after the collision, more or less saying “we meant what we said”.

Like I said, OES available before the collision predicted that the two satellites would pass within 70 meters of one another. Iridium LLC says that they maneuver whenever a pass closer than 5 km is predicted. They may not have updated their predictions in time, I agree.

While Kosmos satellites maneuver, most of their maneuvering is done initially, right after launch to attain the desired orbit and occasionally thereafter for station keeping. It would be very difficult, if not impossible to have two satellites collide passed on ground based commands. U.S. interceptors have on-board sensors and closed loop guidance.

[Lonesome in Massachussets]

I don’t see how there’s room for anything else up there..

The actual collision cross of the satellites and junk is microscopic compared to a single pixel on the scale of the pictures you posted. What counts almost as much is the uncertainty volume for each pair of satellites. The uncertainty volume depends on the confidence level, too. In other words, as you increase the required probability that the satellites won't collide, you need to increase the required prediction distance. What you need to worry about is keeping the uncertainty ellipses from colliding.

Check out this website for a kewl videos of the event. I can tell you that their "statistical model" of the post collision debris (based on a Gaussian distribution) isn't close to the truth.