
Less than a week later, on the morning of April 5th, NASA began monitoring a new debris threat. There was not enough time to coordinate another debris avoidance maneuver, so Mission Control advised the crew to be ready to evacuate to their Soyuz TMA-20 spacecraft as a safety precaution. 7 This debris threat was due to a 2007 anti-satellite missile test conducted by the Chinese space agency. China’s destruction of their weather satellite, Fengyun-1C, resulted in the largest recorded creation of space debris in history, adding at least 2,317 golf ball-sized or larger objects as well as over 35,000 objects measuring more than 1 centimeter. 8 Especially worrisome, the test resulted in “the majority of the debris…thrown into long-duration orbits, with lifetimes measured in decades and even centuries.” 9
Ultimately, the April 5th debris encounter ended without incident. About 1.5 hours prior to the closest approach of the debris, NASA obtained sufficient data to confirm the object would harmlessly pass the Station, albeit at fairly close range (approximately 3.5 miles). With this knowledge, NASA relayed an “all clear” to the Station crew, allowing the astronauts to resume their normal tasks without having to seek shelter in their Soyuz. 10 According to Space.com, NASA and its international partners try to maintain a safety perimeter around Station that is fairly wide (15 miles), but shallow (.5 miles above and below) — like a pizza box.

At orbital velocity (17,500 miles per hour or more), colliding with even a very small object — like a grain of sand or a flake of paint — can cause significant damage. Unfortunately, there are many millions of pieces of space debris that measure less than 1 centimeter in diameter, and none of these objects are trackable with currently available technology and resources. Any object in orbit is at risk of being impacted by MMOD (NASA’s acronym for MicroMeteoroid/Orbiting Debris). Even Space Shuttles, which aren’t in space for more than 10 to 14 days at a time, have sustained some damage on orbit. The first documented example of damage to a Space Shuttle from an orbital debris impact was on STS-7, when a paint flake impacted one of Space Shuttle Challenger‘s windows. Another example of damage occurred during STS-115, when a small fragment of circuit board material damaged a payload bay door radiator on Space Shuttle Atlantis. 11

The scale and complexity of the orbital debris issue can make it difficult to grasp. The Waste in Space infographic does a good job of surfacing important details. For example: Two incidents — China’s anti-satellite mission and the 2009 satellite collision — increased the total amount of orbital debris by more than 60%. 12 If just two collisions can increase space junk that much, all space-faring nations must take heed. Each successive debris-creating event magnifies the risks to orbiting satellites significantly, putting humanity’s efforts in Low Earth Orbit (LEO) and beyond at ever-greater risk. 13
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Part Two of this series will explore how orbital debris is tracked and by whom, as well as methods for reducing space waste.
Notes:
- “Orbital Debris Education Package,” Orbital Debris Program Office, NASA Johnson Space Center. Accessed 15 April 2011. ↩
- “NSSDC Master Catalog Search: Vanguard 1,” National Space Science Data Center. 11 April 2011. ↩
- “UCS Satellite Database“. Union of Concerned Scientists, 15 April 2011. ↩
- “Station Fires Engines to Avoid Orbital Debris.” Space-Travel.com, 4 April 2011. ↩
- “ISS Debris Avoidance Maneuver Threshold Analysis.” NASA / United Space Alliance, May 2007. ↩
- Sincere thanks to @deraven and @Carbon_Flightfor surfacing the above reference for me. ↩
- “Space Junk Forces Astronauts to Seek Shelter.” Space.com, 5 April 2011. ↩
- “Chinese ASAT Test.” Center For Space, 5 December 2007. ↩
- “Handbook for Limiting Orbital Debris.” NASA, 30 July 2008. ↩
- “Space Debris No Threat to Station.” NASA, 6 April 2011 ↩
- “Handbook for Limiting Orbital Debris.” NASA, 30 July 2008. ↩
- “Infographic: Waste in Space.” GOOD & Column Five Media, 17 March 2011. ↩
- “ISS Debris Avoidance Maneuver Threshold Analysis.” NASA / United Space Alliance, May 2007. ↩
cool post! it’s amazing that with as much crap as there is up there that we don’t have more collisions. look forward to the second part. there are some crazy clean up ideas out there…
Great post! This is a serious situation and requires some serious funding from all space-faring nations/organisations to remediate the present debris and reduce future creation.
Great piece of writing, can’t wait to see Part II. I know the UN is increasingly concerned about this, as we all should be. (Acronym DAM?? hahahaha)