(meteorobs) The Latest on the Satellites Collison

Wayne Watson sierra_mtnview at sbcglobal.net
Mon Feb 16 16:53:35 EST 2009


    Iridium 33

    * *Owner:* Iridium LLC <http://www.iridium.com>
    * *Technical operator:* The Boeing Co. <http://www.boeing.com> under
      subcontract
    * *Manufacturer: *Motorola, Inc. <http://www.motorola.inc>
    * *Launched: *14 September 1997
    * *Orbit:* near-circular 776 km x 86.4 degrees polar orbit

Iridium 33, an operational spacecraft in the Iridium phone satellite 
constellation, and Kosmos 2251, a defunct Russian military satellite, 
have collided in low-Earth orbit. The crash took place on 10 February 
2009 at 1656 UTC over northern Siberia, resulting in the destruction of 
both spacecraft.

Kosmos 2251, a Strela store-and-dump communications satellite, was 
launched in June 1993 aboard a Kosmos 3M rocket from Plesetsk, Russia. 
The 900-kg satellite was placed in a 778 km x 803 km x 74 degrees orbit. 
It is likely to have operated for no more than a few years.

"While this is an extremely unusual, very low-probability event, the 
Iridium constellation is uniquely designed to withstand such an event, 
and the company is taking the necessary steps to replace the lost 
satellite with one of its in-orbit spare satellites," Iridium stated.

But that's not the real problem.

Using a computer model, British space debris expert Hugh Lewis predicted 
10,000 tennis-ball-sized debris shards - more than triple the number 
created in China's anti-satellite weapon test in January 2007. "There 
was more energy here than in the Chinese ASAT test so we'll see more 
debris," he was quoted as saying by New Scientist.

Iridium spokeswoman Liz DeCastro said the company had had no advance 
warning of an impending collision. "If the organisations that monitor 
space had that information available, we are confident they would have 
shared it with us." The company (or its subcontractor Boeing) apparently 
did not perform own analyses.

Retired U.S. Air Force General John Campbell, Iridium's executive vice 
president for government programmes, in 2007 told a forum 
<http://www.marshall.org/pdf/materials/554.pdf> hosted by the George C. 
Marshall Institute that Iridium had been receiving a weekly average of 
400 conjunction reports from the U.S. Strategic Command's Joint Space 
Operations Center.

"The ability actually to do anything with all the information is pretty 
limited," he said, describing a kind of data overload. The conjunction 
reports were issued every time a potential threat object was to pass 
within five kilometers of a commercial satellite, he said.

It has been pointed out that Russia was also to blame for the incident. 
Certainly Russian officials could have warned Iridium or its 
subcontractor Boeing of the possibility of an impending collision. 
However, we will never know whether Iridium or Boeing would have reacted 
to such a warning -- or ignored it like the warnings from USSTRATCOM.

Iridium spokeswoman Elizabeth Mailander confirmed that the company never 
performed a single collision avoidance manoeuvre in the entire history 
of its satellite constellation.

/Last updated: 16 February 2009/

-- 

           Wayne Watson (Watson Adventures, Prop., Nevada City, CA)

             (121.01 Deg. W, 39.26 Deg. N) GMT-8 hr std. time)
            
            Shhhh, quiet. I'm thinking about filling this space.** **

****

******
**                    Web Page: <www.speckledwithstars.net/>




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