Subscribe free to our newsletters via your
. Space Industry and Business News .

Speeding Space Junk Poses Risks for Spacecraft
by Doug Bernard for VOA Digital Frontiers
Washington DC (VOA) Dec 10, 2012

Major collisions are rare, but they do happen. On Feb. 10, 2009, two large satellites, the Iridium 33 and the Kosmos 2251, collided at a speed of about 42,000 kilometers per hour. The collision spread about 1,000 pieces of debris capable of being tracked across the skies, where much of it remains.

The amount of space junk floating around the Earth grows every year, and increasingly can pose risks to spacecraft orbiting the planet.

In the United States, NASA's Orbital Debris Program (ODP) at the Johnson Space Center in Texas, keeps an eye on the ever-expanding junkyard of space.

"We define orbital debris as any man-made object orbiting the Earth that is no longer serving a useful purpose," says Gene Stansbery, project manager for the ODP.

"That can be anything from very large rocket bodies and dead satellites that are no longer useful, all the way to very tiny particles that are eroded from the painted surfaces of spacecraft or rockets, the entire size range."

In the weightless and friction-free environment of orbit, it's not so much the size of all this junk floating in the Earth's orbit, but also the speeds at which it travels, according to Stansbery.

"If you look at orbital velocities and the average collision velocity, you're talking on the order of 11 kilometers a second," he says. "So even a small paint fleck can damage a sensitive component for spacecraft."

An example occurred during STS 7, when a window for the space shuttle had to be replaced for the first ever time after being damaged by a .2 millimeter paint fleck. If that level of damage can be caused by a particle that small, one can imagine the threat posed by larger orbiting refuse.

Given that space exploration has been an on-going venture since the 1950s, there's a lot of old stuff circling the planet, and much of it can pose serious risks.

"The Department of Defense has a world-wide network that can track objects down to about 10 centimeters in size in low Earth orbit," says Stansbery.

"For those objects, there's about 22,000 that they're tracking. You go down to about one centimeter and larger, you're talking about 500,000, and if you get smaller than that and you're talking into the millions."

Some of that stuff, especially in low-Earth orbit, will eventually fall back to the planet, much of it burning up on re-entry. However, for junk found at higher altitudes, around 1,000 kilometers or so, Stansbery says it could remain in orbit for decades, maybe even hundreds of years. For altitudes even higher than that, junk could remain for centuries ... or longer.

Major collisions are rare, but they do happen. On Feb. 10, 2009, two large satellites, the Iridium 33 and the Kosmos 2251, collided at a speed of about 42,000 kilometers per hour. The collision spread about 1,000 pieces of debris capable of being tracked across the skies, where much of it remains.

In March of this year, one of those pieces came uncomfortably close to the International Space Station. So close, in fact, that as a precaution, the ISS' six-member crew waited for a time in the Soyuz emergency exit capsule, just in case a collision occurred and they had to abandon ship.

More worrisome, says Stansbery, is that the crew only had 24 hours notice of the possible collision. "Unfortunately, that is too short a time to plan a re-avoidance maneuver for the space station," he says.

The threat posed by space junk isn't new; space scientists have been concerned about it since the 1970s. However, with more rockets taking off, more satellites in the sky, and more spacecraft - such as from China or private firms like SpaceX and Blue Origin - the skies are getting more crowded all the time.

This week on VOA's "Science World" radio program, you can hear the complete interview with Gene Stansbury on space junk, as well as other features on the science behind children's snack food choices, the lingering effects of the Gulf of Mexico oil spill on corral communities, and a new web-based computer program that helps doctors save lives. Take a look at the right hand column for scheduled times.


Related Links
Orbital Debris Program
Space Technology News - Applications and Research

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Schriever squadrons assure safe passage in space domain
Schriever AFB CO (SPX) Dec 03, 2012
Members of the 1st and 7th Space Operations Squadrons took notice when an upper stage Russian rocket disintegrated in low earth orbit Oct. 16. The break up introduced an estimated 500 pieces of debris into an area where the U.S. operates a multitude of satellites, further congesting an already crowded orbit around Earth. The event sheds light on an ever-growing issue for the space and sate ... read more

Elbit Systems to Provide Space Camera for the Italian OPTSAT 3000 Observation Satellite

Speeding Space Junk Poses Risks for Spacecraft

Samsung, Apple top 'smart device' Q3 sales: survey

Smartphones might soon develop emotional intelligence

US Air Force selects Raytheon to develop future Protected SATCOM System

General Dynamics Awarded Contract Under New U.S. Army Rapid-Acquisition Communications Program

Astrium to provide military X-band satcoms to six UK Royal Navy vessels

Lockheed Martin to Demonstrate Key Component of Tactical MilSat Communications System

SPACEX Awarded Two EELV Class Missions From The USAF

Russia Set to Launch Telecoms Satellite for Gazprom

Sea Launch Delivers the EUTELSAT 70B Spacecraft into Orbit

S. Korea readies new bid to join global space club

Third Boeing GPS IIF Begins Operation After Early Handover to USAF

Putin Urges CIS Countries to Join Glonass

Third Galileo satellite begins transmitting navigation signal

Retired GIOVE-A satellite helps SSTL demonstrate first High Altitude GPS navigation fix

US agency chief seeks to ease airplane electronics ban

Japan pedal power aims for human flight record

Swiss to get Swedish jets cheaper than Swedes: report

Canada reconsidering F-35 fighter purchase: reports

New '4-D' transistor is preview of future computers

Ames Laboratory scientists develop indium-free organic light-emitting diodes

Research discovery could revolutionise semiconductor manufacture

Engineers pave the way towards 3D printing of personal electronics

Seeing stars, finding nukes: Radio telescopes can spot clandestine nuclear tests

URI oceanography student uses crashing waves on shorelines to study Earth's interior

Raytheon technology instrumental in creating "Black Marble" image

New test adds to scientists' understanding of Earth's history, resources

Toxic cloud in Buenos Aires under control

Peru industrial pollution feeds conflict

China aims to reduce air pollution

Declining air pollution levels continue to improve life expectancy in US

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement