posted 02-11-2009 03:25 PM               

A commercial Iridium communications satellite collided with a Russian satellite or satellite fragment, Tuesday, creating a cloud of wreckage in low-Earth orbit, officials said Wednesday. The international space station is not threatened by the debris, they said, but it's not yet clear whether it poses a risk to any other satellites in similar orbits.

..."Nothing to this extent (has happened before)," [Nicholas Johnson, NASA's chief scientist for orbital debris] said. "We've had three other accidental collisions between what we call catalog objects, but they were all much smaller than this and always a moderate sized objects and a very small object. And these are two relatively big objects. So this is a first, unfortunately."

posted 02-11-2009 05:00 PM               

"They collided at an altitude of 790 kilometers (491 miles) over northern Siberia Tuesday about noon Washington time," said Nicholas Johnson, NASA's chief scientist for orbital debris at the Johnson Space Center in Houston. "The U.S. space surveillance network detected a large number of debris from both objects."

..."We don't have an air traffic controller in space. There is no universal way of knowing what's coming in your direction."

posted 02-11-2009 05:24 PM               

According to a Feb. 11 e-mail alert issued by NASA, Russia's 900-kilogram Cosmos 2251 satellite collided with the 560-kilogram Iridium craft at 11:55 a.m. Eastern time over Siberia at an altitude of 790 kilometers. The incident was observed by the U.S. Defense Department's Space Surveillance Network, which later was tracking two large clouds of debris.

posted 02-11-2009 06:11 PM               

"As of about 12 hours ago, I think the head count was up (to around) 600 pieces," Carey told CBS News late today. "It's going to take about two days before we get a solid picture of what the debris fields look like. But you, I think, can imply that the majority of that should be probably along the same line as the original orbits."

posted 02-12-2009 02:31 AM               

quote:

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Originally posted by Robert Pearlman:
Based solely on Harwood's articles, it sounds as though the debris cloud was the first indication of the collision.

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posted 02-12-2009 05:35 AM               

1. The US Forces did track the two satellites and could inform people who could change the trajectory of Iridium but chose not to [doesn't matter for which reason]

2. The US Forces didn't know about it...

posted 02-12-2009 06:03 AM               

The US Air Force does do daily a conjunction assessment screening, but for only a limited number of objects. NASA and ESA have looked at all vs all conjunction assessment scenarios (basically screening everything in the catalog vs everything else) and estimated that there would be a few thousand close approaches each day. Sorting through all of those to find the ones that are the real risks, doing follow-up tracking and more detailed analysis to calculate hard probabilities and informing the right authorities requires an amount of resources that no one has at this point.

posted 02-12-2009 12:49 PM               

Space station commander Michael Fincke of NASA told Mission Control today that his crew appreciated the concern and was glad to hear that the satellite collision has not affected the planned early-morning arrival of a new Russian cargo ship at the station on Friday.

"We understand that a lot of people around the planet were worried for our health and safety," Fincke radioed down. "We were touched by that and we'd like to say thank you."

posted 02-12-2009 01:33 PM               

European space scientists were aware of the potential for a close encounter between Russian and U.S. satellites before they crashed.

But the difficulty of predicting orbits and "noise" from thousands of pieces of debris made a definitive prediction of a collision impossible.

"The 'catalogue' of objects and debris showed a possible approach between the paths of the two satellites but an approach doesn't necessarily mean a collision, and you would need more information to be certain," said Philippe Goudy, deputy director of the French space operations control centre at Toulouse.

"It is not a case of two satellites coming together out of nowhere; they had been followed. The U.S. catalogues can give an alert but these are not necessarily completely exact."

posted 02-12-2009 02:48 PM               

• Space traffic congestion needs money and technology

  "It emphasizes the need for expanded safety and navigational situational awareness, as well as the potential benefit of establishing some kind of international standards," said one senior U.S. official, who asked not to be named.

  U.S. defence spending is under increasing pressure, but lawmakers are more apt to back preventative spending now that a major collision -- once considered unlikely -- has occurred, said one congressional aide.

• U.S. warns of space "dodgeball" after satellite crash

  "My worry is that that debris field is going to be up there for a while," said General James Cartwright, vice chairman of the Joint Chiefs of Staff and former head of the military's space operations.

  "So we're going to have to play a little bit of dodgeball for many tens of years to come," he said.

  "The good news is once it stabilizes, it's relatively predictable," he told a forum on the national security implications of operations in space. "The bad news is it's a large area."

• U.S., Russia track satellite crash debris

  "The debris got scattered in all directions, including upwards, where old Soviet satellites are 'buried', those which were intended for surveillance over the navy of a potential enemy ... (and are) equipped with nuclear reactors," Interfax quoted the expert as saying.

  "There is a threat of collision with these spacecraft and therefore of the appearance of radioactive debris in orbit," the expert said.

posted 02-12-2009 06:41 PM               

quote:

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Originally posted by teopze:
To me, both those scenarios resulted in the same, the satellites' collision.

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posted 02-12-2009 08:26 PM               

"Iridium didn't have information prior to the collision to know that the collision would occur," said Liz DeCastro, a company spokeswoman. "If the organizations that monitor space had that information available, we are confident they would have shared it with us."

She was responding to questions about an 18-month-old presentation by retired U.S. Air Force General John Campbell, Iridium's executive vice president for government programs.

Iridium had been receiving a weekly average of 400 conjunction reports from the U.S. Strategic Command's Joint Space Operations Center that tracks debris in space, Campbell told a June 2007 forum hosted by the George C. Marshall Institute, a Washington research group.

"So 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 (3 miles) of a commercial satellite, he said.

"Even if we had a report of an impending direct collision, the error would be such that we might maneuver into a collision as well as move away from one," he told the panel.

posted 02-13-2009 09:05 AM               

The already hobbled Hubble Space Telescope could be further harmed by space debris from Wednesday's unprecedented satellite collision, a chief NASA scientist told ABC News.

There has always been a small risk that Hubble and other spacecraft could be damaged by the thousands of pieces of junk floating through space.

But now that the space telescope is orbiting 75 miles below where the collision took place, experts say the risk is much greater.

"Clearly debris from the event is going through the altitude that the Hubble flies, so we're going to be looking at what is the new risk to Hubble," said Nicholas Johnson, chief scientist at the Orbital Debris Office at NASA's Johnson Space Center.

posted 02-13-2009 08:43 PM               

They said there was no immediate risk to the international space station and its crew of three -- which orbits about 270 miles below the collision -- or to an upcoming shuttle launch to the station. The Hubble Space Telescope, which orbits about 160 miles higher than the space station, is also not considered at risk, NASA officials added.

...right now, they're most worried that orbiting wreckage from the crash could damage or destroy a nearby flock of five satellites, called the A-Train, which monitor Earth's climate.

"The risk is increased. I can't tell you the magnitude of that risk, whether it went up 1 percent, 5 percent or 10 percent. We don't have a lot of information yet to quantify," Johnson said. More answers should be coming in the next few days, he said.

NASA launched the first A-Train satellite in 2002 and since has added four more probes to the close-flying formation, which measures a wide range of data, from radiation to rainfall. A sixth satellite, the Orbiting Carbon Observatory, is scheduled to join the group this month to help track carbon dioxide.

posted 02-15-2009 01:32 PM               

The Federal Aviation Administration (FAA) has a report suggesting this might have been debris from last week's satellite collision.

Possible Satellite Debris Falling Across the Region

The National Weather Service in Jackson [KY] has received calls this evening from the public concerning possible explosions and/or earthquakes across the area. The Federal Aviation Administration has reported to local law enforcement that these events are being caused by falling satellite debris. These pieces of debris have been causing sonic booms resulting in the vibrations being felt by some residents as well as flashes of light across the sky. The cloud of debris is likely the result of the recent in orbit collision of two satellites on Tuesday, February 10th when Kosmos 2251 crashed into Iridium 33.

posted 02-15-2009 07:50 PM               

U.S. Air Force Lt. Col. Terry Plumb, a spokesperson for the U.S. Strategic Command, told SPACE.com that the center received a 911 call from just outside Houston, Texas, but was awaiting confirmation that it was actually caused by debris from the Iridium 33-Cosmos 2251 satellite crash.

"We haven't received any official reports here yet," Plumb said.

"Late this morning, people started reporting to law enforcement there was a quote-unquote fireball and some people reported an explosion, which we suspect was probably a sonic boom," said Roland Herwig, a spokesman for the FAA's Southwest Region. "We had put out, the FAA had put out a notice to airmen, called a NOTAM, yesterday morning for pilots, for air crews to be on the lookout for space debris re-entering and and if they see anything to let the FAA know the location, the direction of travel, anything else they could about that. The notice to airmen says we suspect, we don't know, that this debris is from the two satellites that collided last week."

The actual NOTAM, however, does not mention the space collision Tuesday between a commercial Iridium telephone satellite and a defunct Russian communications station known as Cosmos 2251.

posted 02-15-2009 07:54 PM               

A video of the fireball has been released, taken by a person videotaping a footrace. The video matches the description of many eyewitnesses.

...the video shows the fireball to be moving very rapidly. Typically, meteors come into Earth's atmosphere at 20-50 km/sec (though they can be moving much faster), and burn up 50-100 km high. Man-made space debris re-entering is moving at slower than orbital speed so the max speed is about 8 km/sec. It also burns up lower, and generally you can see flames and whatnot coming off.

I've seen man-made debris re-enter, and it's very different than natural meteors. The difference in speed is very obvious. Right there, that's enough to make me think this was a single natural object.

posted 02-16-2009 09:09 AM               

The U.S. Strategic Command said there was no connection to reports of a "fireball" in the sky over Texas on Sunday and Tuesday's collision of satellites from the U.S. and Russia.

"There is no correlation between the debris from that collision and those reports of re-entry," said Maj. Regina Winchester, of STRATCOM.

On Saturday, the FAA issued a notice for pilots to be on the lookout for falling space debris until further notice. On Sunday night, that notice was removed and being rewritten to attribute the concern to a "natural source."