Space debris monitoring in Tenerife
April 18, 2009 1 Comment
During February 2009 there was a space collision between a Russian communications satelleite and an American commercial spacecraft resulting in thousands of pieces of orbiting space debris. At the time, some observers put the odds of such an event occurring at millions, maybe billions, to one.
But experts had been warning for years that useable space was becoming crowded, boosting the possibility of a serious collision. They have argued both for better monitoring of the space environment and for policies aimed at controlling the production of debris.
There are thought to be some 18,000 objects larger than 10cm orbiting Earth, but millions more that are smaller. Intact satellites share Earth’s orbit with everything from spent rocket stages, tools lost on spacewalks and spacecraft wreckage including paint flakes and dust. There is space debris from more than half a century of human activities in space.
At orbital speeds of 27,000km/h (17,000mph), even tiny pieces of debris can knock out a satellite or kill a spacewalker. And as the number of pieces of debris grows, so does the threat of collisions. In the longer-term, computer modelling work has identified a worrying effect called a “collision cascade”, a kind of domino effect where collisions create more debris, which generates further collisions, creating even more debris.
Until now, Europe has been largely dependent on the US for knowing what is going on in space. But European observers have for some time regarded this situation as inadequate. Officials will spend three years assessing what Europe needs to develop its capabilities in space situational awareness. Radar is generally used to track objects in low-Earth orbit, while optical telescopes are often used to observe objects further away from the Earth.
Gaele Winters, European Space Agency’s (ESA) director of operations and infrastructure, says: “There are member states in Europe with their own facilities. Esa also has some facilities. If you combine [those resources] in an intelligent way, you can reach a point where it is possible to deliver precursor services.”
These existing facilities might include France’s GRAVES (The French acronym means large-scale system adapted for space monitoring) radar system, which can survey objects in low-Earth orbit up to distances of 2,000km, the Zimmerwald optical telescope observatory in Switzerland, and the ESA Space Debris Telescope at the Teide Observatory in Tenerife.