I saw the movie Gravity today .. here is its trailer on YouTube. It’s a survivor film, but also draws attention to the problem of debris in space. Bharath Gopalaswamy writes on the Huffington Post blog that there are now 22,000 trackable pieces of debris in low earth orbit. From the blog : U.S. Strategic Command’s Joint Space Operations Center monitors space debris with a worldwide network of 29 ground-based radars and optical sensors. The center also provides notifications to commercial space operators of potential risks to their satellites from space debris. In 2010 alone these warnings resulted in 126 satellite maneuvers to avoid collisions with other satellites or debris. But no country on its own has the resources, the technical expertise, or the geographical reach to resolve the problem of situational space awareness, thus making international cooperation a pivotal element towards mitigating risks to objects in space.