Showing posts with label Iridium-Cosmos collison. Show all posts
Showing posts with label Iridium-Cosmos collison. Show all posts

Thursday, November 05, 2009

As Space Collision Threat Looms, Pentagon Upgrades Its Monitoring of Satellites

Space Junk An artist's impression of space debris in low-Earth orbit. The U.S. government wants a better surveillance system to keep track of the thousands of space junk pieces. ESA

By Jeremy Hsu on the Popular Science website

The U.S. Air Force has upgraded its ability to predict possible satellite collisions, as the risk from space debris increases

Satellites currently must dodge an ever-growing gauntlet of other satellites and clouds of space debris, and this year the Pentagon has quietly upgraded its surveillance accordingly. The U.S. military announced yesterday that it now tracks 800 maneuverable satellites, compared to less than 100 prior to a February collision between an active U.S. satellite and a retired Russian communications satellite.

That crash served as a wakeup call and emphasized the vulnerability of U.S. satellites, according to General Kevin Chilton, commander of U.S. Strategic Command. Reuters reports that the Air Force also plans to track an additional 500 non-maneuvering satellites by the end of year, and thereby keep tabs on the roughly 1,300 active satellites currently in orbit.

Read more . . .

Friday, February 13, 2009

Satellite Collision Debris May Affect Space Operations, Cartwright Says

By Air Force Master Sgt. Adam M. Stump Special to American Forces Press Service

WASHINGTON, Feb. 12, 2009 - The collision yesterday of two communication satellites has left a debris pattern that may affect future space operations, the vice chairman of the Joint Chiefs of Staff said at a symposium here today co-sponsored by the George C. Marshall Institute and the U.S. Chamber of Commerce's Space Enterprise Council.

U.S. Marine Gen. James E. Cartwright, speaking on the national security ramifications of the collision between an American and a Russian satellite, said the event shows the need for better information sharing and space situational awareness.

The American satellite, owned by Iridium Satellite of Bethesda, Md., weighed about 1,200 pounds and collided with a Russian satellite that had been nonoperational for more than a decade. The crash happened 491 miles above Siberia. The collision was confirmed when the active U.S. satellite did not report in and the debris field was picked up by sensors.

"My worry is that debris field is going to be up there for about a year, so we're going to have to play a little bit of dodgeball," Cartwright said. "It's going to be a problem because it will take a month or two for the debris to settle down and for us to understand the scope of the field to be able to track it and understand where at least the larger objects are."

The debris will be around for some time because the satellites were in a high orbit around the earth, Cartwright said. Once the debris field has stabilized, there will be a pattern that all countries can use to navigate around, he said.

"It's a field of debris out there that's going to be out there for many years," he said. "The good news is once it's stabilized, it's relatively predictable. The bad news is, it's a large area. If we're denied that large area for use, it becomes a problem."

Many of the commercial and national security satellites, particularly communications satellites, rely on certain spacing between other objects in order to be effective, Cartwright said. Losing a spot because of debris could have a financial or operational impact on anyone wanting to use the space, he said.

"If that's going to be long term, that's a problem for us," he said.

The general said he hopes the incident will result in a better exchange of satellite orbit data between countries.
"I'd like to be able to find a way, not only with Russia, but with other nations to make sure that our exchange of data is more complete," he said. "We would be remiss to not take advantage of this and turn it into good."

The growing number of satellites require improved information sharing, Cartwright said. "It is a crowded place out there today," he said. "There is just no way around that. The need, first and foremost, for better situational awareness out there is something you have to actively pursue."

The need for space situational awareness has changed drastically in recent years, the general said. "It was acceptable five years ago to know something was out there and check on it every couple weeks," he said. "Those days are just not tolerable anymore."

Whereas countries previously could wait a few days or weeks to get satellites stabilized in their orbits, the current congestion in space pushes that timeframe down to seconds and minutes, he said.

Thursday, February 12, 2009

Iridium, Cosmos Satellites Collide in Space - Update

In an unprecedented space collision, a commercial Iridium communications satellite and a non-operational Russian Cosmos military satellite ran into each other Tuesday at around 1656 UTC above northern Siberia, creating a cloud of wreckage, government officials said yesterday.

They two satellites have been identified as Cosmos 2251 and Iridium 33.

Cosmos 2251
USSPACECOM Catalog No.: 22675
International Designation Code: 1993-036A
Satellite Details Orbit: 767 x 803 km, Inclination: 74.0°
Launch Date (UTC): June 16, 1993 (0417 UTC)
Mission: Russian Strela-2M military store-dump communications satellite (non-operational)
Launch Site: Site 132/1 at the Plesetsk Cosmodrome
http://www.astronautix.com/craft/strela2m.htm

Iridium 33 (Also called Iridium SV033)
USSPACECOM Catalog No.: 24946
International Designation Code: 1997-051C
Satellite Details Orbit: 783.0 x 798.2 km, Inclination: 86.4°
Launch date: September 14, 1997
Mission: LEO Communications Satellite
Launch site: Baikonur Cosmodrome, Kazakhstan
Launch vehicle: Proton K #252
http://www.astronautix.com/project/iridium.htm

"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."

Animated version of the collison at this link http://i39.tinypic.com/2vbk75z.gif (Courtesy of John Locker)

Air Force Brig. Gen. Michael Carey, deputy director of global operations with U.S. Strategic Command, said initial radar tracking detected some 600 pieces of debris.

Iridium Satellite LLC operates a constellation of some 66 satellites, along with orbital spares, to support satellite telephone operations around the world. The spacecraft, which weigh about 1,485 pounds when fully fueled, are in orbits tilted 86.4 degrees to the equator at an altitude of about 485 miles. Ninety-five Iridium satellites were launched between 1997 and 2002 and several have failed over the years.

More on this story at
http://spaceflightnow.com/news/n0902/11iridium/


Here is an computer generated image of all the orbital debris in low earth orbit (LEO). LEO stands for low Earth orbit and is the region of space within 2,000 km of the Earth's surface. It is the most concentrated area for orbital debris. (Courtesy of the NASA Orbital Debris Program Office)

The last major spacecraft fragmentation and probably the most famous, was the intentional destruction of the Chinese Fengyun 1C weather satellite by a Chinese ASAT weapon. The current debris count from that incident now stands at 2,530 pieces.