Two Satellites Collide

[ozone]

http://spaceflightnow.com/news/n0902/11iridium/

 

[T.Neo]

Kessler syndrome...

 

[Ark]

Seems surprising that nobody saw this coming.

 

[TSPenguin]

The obvious question is: Is anyone making a Scenario?

More detail about the orbits would be interesting, especialy the Rinc.

 

[James.Denholm]

Reminds me of my docking technique...

 

[tblaxland]

More detail about the orbits would be interesting, especialy the Rinc.

Well Cosmos 2251 was at 74.0° and the Iridiums fly at 86.4°, so the minimum RInc is 12.4°. At an orbital velocity of 7460m/s (790km circular), that makes an impact velocity of sin(12.4)*7460 = 1602m/s! Pretty substantial, as a minimum.

 

[Urwumpe]

Well Cosmos 2251 was at 74.0° and the Iridiums fly at 86.4°, so the minimum RInc is 12.4°. At an orbital velocity of 7460m/s (790km circular), that makes an impact velocity of sin(12.4)*7460 = 1602m/s! Pretty substantial, as a minimum.

Don't forget LAN.

You could also have a head-on collision, even at the same inc.

 

[SlyCoopersButt]

Satellites play roulette with each other every day, It's quite inevitable event they lose on occasion. It's really something to think about as the stakes get higher every year. What number was that Iridium Satellite? Didn't see it mentioned.

 

[mbartley]

From the SeeSat-L email list:

Date: Wed, 11 Feb 2009 16:13:57 -0800 (PST)
From: T V I <[email protected]>
Subject: Re: Iridium, Cosmos collide
To: [email protected]

.....And short animation
[URL]http://i39.tinypic.com/2vbk75z.gif[/URL]

At a glance, RInc was close to 90 degrees!

 

[spacetrack]

it was number 33, or 24946

the big problem here is that there's a few more iridiums in the same orbit trying to dodge a ring of debris.

also because its happened above the iss, they're gonna have a shower of debris. abandon ship?


-----Post Added-----

From the SeeSat-L email list:

Date: Wed, 11 Feb 2009 16:13:57 -0800 (PST)
From: T V I <[email protected]>
Subject: Re: Iridium, Cosmos collide
To: [email protected]

.....And short animation
[URL]http://i39.tinypic.com/2vbk75z.gif[/URL]

At a glance, RInc was close to 90 degrees!

do you know which program thats run on?

we put it through STK today and got the same results.

 

[tblaxland]

Well Cosmos 2251 was at 74.0° and the Iridiums fly at 86.4°, so the minimum RInc is 12.4°. At an orbital velocity of 7460m/s (790km circular), that makes an impact velocity of sin(12.4)*7460 = 1602m/s! Pretty substantial, as a minimum.

Don't forget LAN.

You could also have a head-on collision, even at the same inc.

I am well aware of that - notice the use of the word minimum I just didn't have any LAN data to hand.

 

[David413]

Working on a scenario, but propagating the last good set of elements isn't yielding anything closer than an approach of about 100 km (around 13:34 UTC on 2/10/09). I'm not giving up yet, but the tools I have may not be up to the task...

 

[Zatnikitelman]

I don't suppose anyone on here knows Gravity simulator enough to produce a simulation of the spread of debris like someone did in my "Shotgun effect...SO WHAT?" topic back on the old M6?
Has anyone calculated the chances of a collision like this? 1 in a billion, trillion, googolplex?

 

[James.Denholm]

If the important people had been paying attention and tracking the satellites, the chance would have been zero.

 

[Omhra]

we are eventually going to need a large rubber foam net to go collect all this garbage.. or like in the movie "Wall-e" we are going to be trapped under all the trash.

 

[Ark]

The obvious question is: Is anyone making a Scenario?

That would be tough without collision detection. :lol:

 

[garyw]

If the important people had been paying attention and tracking the satellites, the chance would have been zero.

Not true. It's hard to track a satellite that's dead as it requires several radar fixes to work out it's height, position, speed, direction and so on.

 

[simonpro]

Well they did realise they were going to come close, there was a warning 5 days before that they'd pass within 500m.
I don't know whether the people at Iridium didn't get it (unlikely) or if they just ignored it as teh chance of a hit was so small.
The upside is that it's caused a hell of a mess, so we'll probably get more hits now.

 

[Hielor]

Not true. It's hard to track a satellite that's dead as it requires several radar fixes to work out it's height, position, speed, direction and so on.

If that were true, then how are people able to track the debris ("upwards of 600 pieces") from the collision, or other small objects which are even smaller than the satellite was?

 

[Ghostrider]

The obvious question is: Is anyone making a Scenario?

But the real question is: will it be UMMU-compatible?