15 October 2010
Space Debris' Environmental Impact
by Launchspace Staff
During the first 40 or so years of accumulating this debris, it was little more than a passing thought and at most an irritant, certainly not seriously considered as a future threat to space commerce and applications. In 2007, China tested an anti-satellite weapon on one of its own expired weather satellites in a polar orbit at an altitude of 865 km.
The test was reported to be a success and the resulting debris immediately increased the number of tracked RSOs by 25%. In 2009, and expired Russian Cosmos spacecraft and an active Iridium satellite collided at an altitude of roughly 800 km, and the result was several hundred new RSOs.
Current estimates place the total number of trackable RSOs at about 22,500 with most of these in an altitude band of approximately 700 km to 1200 km. In addition, there are thought to be millions of debris objects that are too small to track. While it is true that operational spacecraft in this altitude band are at risk of colliding with debris, space is still "big" and collision probabilities are still low.
However, the continued growth of debris appears unstoppable. It took just over 50 years before the first satellite-to-satellite encounter took place. The next one will surely occur in much less than that time. Concern regarding space debris is definitely moving from irritant to concern to a call for action.
For several reasons, Action is unlikely to occur anytime soon. The technology for removing RSOs does not exist. Although there are many suggestions, none are practical at this time. The economics of debris removal are simply overwhelming. Culturing and political issues may prove to be the most difficult to overcome. It seems entirely possible that access to space may be denied at some point in the future.
All developed nations already heavily depend on space to provide vast economic advantages that did not exist just 30 years ago. A loss of space applications could set the world back several decades in terms of communications, weather forecasting, scientific exploration, precision navigation and Earth observations.
Is there any good news? One could say that space debris is a
growth industry, but there seems to be no customers who will pay for
cleaning it up. The big question at the moment is: What are the
long-term effects of space debris on access to space and on the
Earth's environment. These topics will be discussed in Launchspace's
new course addition: Space Debris and the Future of Space Flight in
the spring of 2011.