×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

NASA's Fermi Spacecraft Dodged a Defunct Russian Satellite

Soulskill posted about a year ago | from the evasive-maneuvers dept.

Space 47

g01d4 writes "On March 29, 2012, NASA scientists learned that the space agency's Fermi Gamma-ray Space Telescope was headed for a potential conjunction (close approach) with Cosmos 1805, a defunct Russian satellite from the Cold War era. The team knew that the only way to move Fermi would be to fire thrusters designed to move the spacecraft out of orbit at the end of its operating life. On April 3rd, shortly after noon EDT, the space agency fired all thrusters for one second. When it was over, everyone involved 'just sighed with relief that it all went well.' By 1 p.m., the spacecraft had returned to its mission."

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered

47 comments

Should we assume the delay... (1)

rmdingler (1955220) | about a year ago | (#43604425)

In the story's release was a matter of national security, or just normal time lapse between an event's occurrence and discussion on /.

Re:Should we assume the delay... (1)

Anonymous Coward | about a year ago | (#43604477)

It was due to time dilation.

Re:Should we assume the delay... (1)

forand (530402) | about a year ago | (#43605703)

No. It wasn't news then for the same reason there are no highly moderated posts on the article now: it isn't news. When this occurred the community (of gamma-ray astronomers) knew it was happening. It was never kept secret.

Re:Should we assume the delay... (1)

davester666 (731373) | about a year ago | (#43607057)

Yes, to prevent this satellite from possibly turning into junk now, we are now committed to turning it into space-junk later, for our kids satellites to deal with.

In Soviet Russia.. (1)

Anonymous Coward | about a year ago | (#43604429)

Satellite Dodge You!

Why avoid it? (1)

ArcadeMan (2766669) | about a year ago | (#43604475)

Nuke it from orbit, it's the only way to be sure. Not to mention that it's already in orbit.

Re:Why avoid it? (2)

Stolpskott (2422670) | about a year ago | (#43606875)

Nuke it from orbit, it's the only way to be sure. Not to mention that it's already in orbit.

Nice idea... simple solution... but if we take this seriously (sorry, too early in the morning for my sense of humour to have woken up yet) the only problem with it is that any explosive method of dealing with orbiting debris just creates lots of small and tiny pieces of shrapnel, and traveling through a field of that crap at orbital velocities is not going to be the highlight of your day. Not a problem if you are in an M1 Abrams battle tank, but satellites do not have armour, except for shielding against the sun's radiation, and things like solar panels do not work very well after being hit a few times by orbital debris.
What we REALLY need is a small version of Mega Maid (http://www.youtube.com/watch?v=VptOUWC-Itc) to go up there and hoover up all the junk, preferably while leaving all the viable stuff alone.

Re:Why avoid it? (0)

Anonymous Coward | about a year ago | (#43607275)

Nuke it from orbit, it's the only way to be sure. Not to mention that it's already in orbit.

Nice idea... simple solution... but if we take this seriously (sorry, too early in the morning for my sense of humour to have woken up yet) the only problem with it is that any explosive method of dealing with orbiting debris just creates lots of small and tiny pieces of shrapnel, and traveling through a field of that crap at orbital velocities is not going to be the highlight of your day. Not a problem if you are in an M1 Abrams battle tank, but satellites do not have armour, except for shielding against the sun's radiation, and things like solar panels do not work very well after being hit a few times by orbital debris.
What we REALLY need is a small version of Mega Maid (http://www.youtube.com/watch?v=VptOUWC-Itc) to go up there and hoover up all the junk, preferably while leaving all the viable stuff alone.

Does anyone know if an M1 Abrams battle tank can stand up to that? What I've read about space junk is that the high velocities endow great destructive results.

Re:Why avoid it? (1)

wallsg (58203) | about a year ago | (#43606943)

Nuke it from orbit, it's the only way to be sure. Not to mention that it's already in orbit.

Be careful. It might not be Cosmos at all. It might be IKON and it'll nuke you back.

cold war just got hot (2)

jehan60188 (2535020) | about a year ago | (#43604545)

this is clearly a premeditated act of war by the russians. I propose we attack Uzbekistan.

Re:cold war just got hot (1)

khallow (566160) | about a year ago | (#43604555)

I propose we attack Uzbekistan.

Why not attack Hawaii instead? The weather is nicer.

Re:cold war just got hot (1)

camperdave (969942) | about a year ago | (#43604899)

Meh. Why do all that attacking? If the weather is nice, why don't we just lie on the beach with little umbrella drinks?

Re:cold war just got hot (0)

Kittenman (971447) | about a year ago | (#43606187)

this is clearly a premeditated act of war by the russians. I propose we attack Uzbekistan.

Thanks god that George W. isn't still in office... he probably would.

Re:cold war just got hot (0)

Anonymous Coward | about a year ago | (#43607833)

Ya, president Barack Osama will just use drone attacks on American citizens in the USA to distract the Russians while he hands out more foreign aid to the Taliban in Syria.

"we don't need no stinkin' constitution" anyway.

(a once proud American who is looking to emigrate)

Bad headline (1, Informative)

MasseKid (1294554) | about a year ago | (#43604657)

Dodged evidently doesn't mean it was going to hit it and they moved it out of the way. It was actually a "close approach" as stated in the summary (gotta love sensationalism, right?). Except, close approach actually means within 700' of the defunct satellite, which really isn't all the close at all.

Re:Bad headline (5, Informative)

Doug Otto (2821601) | about a year ago | (#43604675)

From TFA:

Though Fermi was expected to miss Cosmos by several-hundred feet, NASA scientists knew from experience that forecasting spacecraft positions a week in advance isn’t an exact science. For example, Iridium 33 and Cosmos 2251 collided in 2009 even though they were predicted to miss each other by approximately 1,900 feet. This was the first known satellite-to-satellite collision.

Re:Bad headline (5, Informative)

X0563511 (793323) | about a year ago | (#43604695)

If there was any debris from the Cosmos (either directly from it, or from interactions with other junk or such) could be within that area.

Our radar is not good enough to make it safe enough to pass by that closely.

Re:Bad headline (2, Informative)

Anonymous Coward | about a year ago | (#43604987)

700' is ridiculously close when you're going miles per second and the Earth's atmosphere is constantly changing, changing each object's orbits by similar amounts regularly due to drag.

Heck, if the RADAR producing the data has a couple of microseconds of jitter in it's clock, the propagation estimates could be off by that amount....Basically, 700' is pretty close to the noise of our estimations for orbital objects like this, and it's just better to be safe than sorry. Not to mention, who knows what small pieces could have broken off of that satellite and be orbiting nearby it....

Re:Bad headline (0)

Anonymous Coward | about a year ago | (#43605005)

So you think they moved it for no reason? Good reasoning. Well thought out.

Re:Bad headline (1)

DerekLyons (302214) | about a year ago | (#43605237)

Except, close approach actually means within 700' of the defunct satellite, which really isn't all the close at all.

Except, you don't know the margin of error in either our knowledge of Fermi's orbit or that of Cosmos 1805's orbit. But I'd be willing to bet that the margins are large enough that a predicted 700' approach would place the two spheres of position sufficiently in overlap that there was a non-zero chance of collision.

Re:Bad headline (1)

AK Marc (707885) | about a year ago | (#43605475)

The margin of error is greater than 700', so it's improbable but possible. And with such dire consequences in the event of a collision, it was safer to move it.

Re:Bad headline (1)

steelfood (895457) | about a year ago | (#43611419)

Actually, revised calculations made their pass even closer, within 30 milliseconds [csmonitor.com] . I may be doing the math wrong, but it seems like that's much closer, like an order of magnitude closer than 700' and then some.

Launched when? (0)

Anonymous Coward | about a year ago | (#43604693)

During the cold war? It's got nukes in it, that's why they didn't wanna hit it!

Orbital Envoirment Protection Agency.... (1, Interesting)

rts008 (812749) | about a year ago | (#43604711)

It seems to have reached a point where the amount of orbital garbage is causing major (and expensive) problems.
I think that if anyone puts a sat in orbit without dodging capability, they are fools, and potentially contributing to the 'littering' of orbitals.

It's past time to start working on and TESTING solutions to clean up the orbitals before it gets even more out of hand.

Or is this some Earthshade Anti-Warming scheme I missed hearing about?

Re:Orbital Envoirment Protection Agency.... (4, Insightful)

bobbied (2522392) | about a year ago | (#43605209)

Oh man, where do you start with this?

In LEO, orbiting debris are a self limiting problem. They will eventually deorbit on their own. So I guess that's not an issue for you.

In Geosynchronous orbit, every object is going to be pretty much moving in exactly the same direction anyway so the relative velocity is really small. The risk of collision is pretty small and the debris created would be minimal at low collision energies.

Outside these two areas, collecting orbiting debris, which vary in size from a few tons down to a few grams is a daunting task at best. How do one would imagine this could be done is the stuff of science fiction at best. Any collection system would by definition need to collect varying sized objects passing though a huge (by human standards) volume. This means there will need to be some pretty large structures launched, flown in space, survive the impact of collecting the desired objects and dispose of the collected mass. All this will need to happen without adding to the problem....

I just don't see how we are going to do this.

Personally, mankind would be better off if we took a debris mitigation strategy that required all launched hardware be mindful of not creating debris in orbits that would not naturally reenter within 5 years or so. We do this kind of thing now, at least the responsible people throwing most of the stuff in to space do, no telling what DPRK does.

Other than that, we might want to start thinking about building "space tugs" that can capture the junk that's collecting in geosynchronous orbit, tug it to less popular locations and work on ways to recycle parts of it. It sure doesn't seem worth the effort to deorbit the stuff that is that high up.

Re:Orbital Envoirment Protection Agency.... (1)

barjam (37372) | about a year ago | (#43605241)

Wouldn't altitude and velocities in geosynchronous orbit have to be exactly identical by definition? Otherwise it wouldn't be geosynchronous orbit and stuff would drift forward or backward.

Re:Orbital Envoirment Protection Agency.... (0)

Anonymous Coward | about a year ago | (#43606207)

Every object in orbit at a certain altitude is moving at the same speed, but they don't have to be moving in the same direction. Of course, there's no point in sending something all the way to 26km if you don't want it to be geostationary, so in practice everything there is moving together.

So you're right, but there could be other stuff at that altitude that's not in geosynchronous orbit.

Re:Orbital Envoirment Protection Agency.... (3, Informative)

Anonymous Coward | about a year ago | (#43606467)

If you want to be pedantic, no. "Geosynchronous" means that it has a 1-day orbital period but does not specify the inclination or eccentricity of that orbit. The correct term for what you're talking about is "geostationary".

Re:Orbital Envoirment Protection Agency.... (1)

sayno2quat (1651749) | about a year ago | (#43621729)

The GP has a point. The GGP states they have little relative velocity, which means they would have to have the same inclination. A geosynchronous satellite that is moving in the opposite direction is going to have a ton of relative velocity and would have disastrous results in the event of a collision.

So perhaps the GPP meant geostationary (or close to it), not just geosyncronous (if the only definition of that is the satellite has a 1-day orbit). However, I am not an astrologer or any sort of scientist, so correct me if I am making incorrect assumptions.

Re:Orbital Envoirment Protection Agency.... (0)

Anonymous Coward | about a year ago | (#43605337)

Putting shit into space is still pretty expensive. First guy who figures out how to start capturing and bolting this stuff together is going to have a pretty nice gig.
Don't wait for spaceX to do it. They just cut the cost enough to undercut the good ole boys.
Meanwhile the governments of the world will continue to run space programs on the backs of taxpayers for 100x cost. Because taxpayers are basically very stupid people.

Re:Orbital Envoirment Protection Agency.... (0)

Anonymous Coward | about a year ago | (#43610189)

I just don't see how we are going to do this.

lasers?

Re:Orbital Envoirment Protection Agency.... (1)

bobbied (2522392) | about a year ago | (#43619347)

And exactly how do you propose this would work with lasers?

Two effects of lasers could be useful, but I don't think either of them really helps in any useful way.

One, you could push an object with a laser. The effect is pretty small, but you could adjust an object's orbit by giving it a small push from time to time. I suppose you could eventually get it to re-enter if you can adjust the orbit enough over time. This would take a LONG time considering you would likely want the laser to be earth based so you could only push on the object at irregular intervals based on the object's orbit and the direction the laser can push it at any given time. I don't think that's going to be a usable situation.

The other effect is heating. Again, this effect is pretty useless. If you succeeded in turning an object into molten slag, all it's going to do is turn into a bunch of small round objects with the same mass as the original object (best case). Their orbit won't change and you have simply made the problem of gathering up the junk harder. I suppose you could hope to vaporize the thing, but that is going to take a LOT more energy.

Lasers just don't seem to be a viable option here.

Re:Orbital Envoirment Protection Agency.... (1)

steelfood (895457) | about a year ago | (#43611447)

A very, very large aerogel sponge. Getting the actual sponge to deorbit would be a bitch, but at least it'd be easy to track.

Re:Orbital Envoirment Protection Agency.... (1)

k6mfw (1182893) | about a year ago | (#43605349)

perhaps international policies to prevent a "tragedy of the commons."

In soviet russia... (0, Funny)

Anonymous Coward | about a year ago | (#43604767)

spacecraft dodges you....

[i'm sorry. the voices told me to tell that]

Re:In soviet russia... (1)

flyingfsck (986395) | about a year ago | (#43606369)

Well, Yuri Gagarin is still flying and he has right of way...

(Legend has it that he didn't die in a plane crash in 1968 and is still in orbit.)

Re:In soviet russia... (0)

Anonymous Coward | about a year ago | (#43610691)

You mean, like Major Tom?

Curious that we aren't working on clearing junk (1)

wnfJv8eC (1579097) | about a year ago | (#43606521)

Orbit. So easy to make an object leave it's orbit. Change is vertical moment. So, a ground based laser, solar powered, naturally, is used to target junk just under the base station. A few minutes a days and this junk will be coming down. Why are we waiting?

Re:Curious that we aren't working on clearing junk (2)

cusco (717999) | about a year ago | (#43606743)

Because no one is willing to pay a gazillion dollars to provide bonuses to aerospace executives. Once the C-suite execs find a sponsor you'll suddenly hear what a high priority clearing out orbital debris has become.
Check for New Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...