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. Credit: NASA
The worrisome build-up of human-caused orbital debris has reached a critical point.
Collisions between objects will continue to occur, and so will impact damages to operational spacecraft. The trend will get worse unless more aggressive actions — such as active debris removal, or ADR for short — are implemented in the future.
That’s the view of Jer-Chyi Liou of the Orbital Debris Program Office at NASA’s Johnson Space Center in Houston, Texas.
“As the international community gradually reaches a consensus on the need for ADR, the focus will shift from environment modeling to completely different challenges – technology development, systems engineering, and operations,” Liou explains in the July issue of The Orbital Debris Quarterly News just issued by the NASA Orbital Debris Program Office.
The four critical “Cs”
To begin to literally grapple with a long-term strategic plan for removing orbital clutter, Liou calls for four critical “Cs” that will be needed at the international level:
— The first “C” stands for consensus on active debris removal.
— The second “C” is for cooperation – the removal targets may belong to a different country.
— The third “C” is for collaboration – it is highly unlikely that any single organization or country can accomplish the goal by itself.
— The last “C” stands for contributions – cost-sharing will be the key for using active debris removal to preserve the environment for future generations.
Addressing key questions
Liou explains that several key questions must be addressed at the beginning of any active debris removal (ADR) planning. They include (1) where is the most critical region for ADR, (2) what are the mission objectives, (3) which debris should be removed first, (4) what are the benefits to the environment, and finally, (5) how to carry out the operations.
The bottom line is that for controlling future debris population growth or reducing collision activities in the environment, Liou points out that removal operations should focus on large — at least several meters in dimension — rocket bodies or spacecraft. For reducing mission-ending threats to operational spacecraft, the focus should be on the 5-millimeter-to-1-centimeter debris.
“Targeting anything outside these two size regimes will not be an effective means to remediate the environment nor to mitigate mission-ending risks to operational spacecraft,” Liou concludes.
If you’re on the lookout for more information on orbital debris, go to:
http://www.orbitaldebris.jsc.nasa.gov/
By Leonard David