November 9, 2012
Space Junk The Target Of New Scottish Stardust Project
John P. Millis, Ph.D. for redOrbit.com — Your Universe Online
In late 2011 the National Research Council released a report stating that the amount of “space junk” orbiting the Earth had reached a tipping point. Since the 1960s, as the United States and others began launching satellites and rockets into space, the region known as Low Earth Orbit (LEO) has become increasingly crowded.
The problem has become so significant that, when the Space Shuttle fleet was still operating, NASA averaged two window replacements on the orbiters after each mission because of collisions with space debris.
Collisions have also permanently damaged satellites and even threatened the International Space Station (ISS). Space agencies have begun to address the problem, and the US Air Force, in 2010, launched a $800 million program to help track the more than 500,000 individual pieces of space junk thought to be in LEO.
Tracking Space Junk
While programs have found some success, limitations in resources and technology restrict our ability to identify all of the debris. Currently, space agencies actively track about 22,000 pieces of space junk; many of these items are disused satellites, small asteroids, and various manmade components left over from earlier missions.
It is not just large, easy to track debris that is the problem however; these tend to be easier to track and satellites and manned craft can usually be maneuvered to avoid them. More worrisome are pieces as small as a centimeter that can pack a mighty punch simply because of the velocities at which they travel.
With so much junk in LEO, agencies are currently developing strategies to deal with the growing problem. Recently, Scotland launched the $4.8 billion Stardust project to develop and execute a long-term strategy for dealing with space junk that will most likely threaten current and future missions.
A significant portion of the funds will be spent on developing ways to track the space debris. But more importantly, new ways to actually deal with the junk that is identified will be investigated over the next four years.
One technology being discussed uses high powered laser beams to vaporize debris, while other proposals call for collecting the debris and moving it to a “graveyard orbit” where satellites and manned space craft never operate.
Whichever technology is ultimately selected, the importance of the work cannot be undervalued. As more countries push forward with space programs, LEO is becoming more littered with space junk that could threaten technology or, worse, human life. This problem has been ignored for far too long; but steps are finally being taken to correct it.