CubeSats could be a major risk for orbital debris collision

New Scientist : CubeSats are 10-cm³, 1.3-kg satellites that provide a relatively inexpensive way for small experiments to be put into Earth orbit. As a result, more and more are being launched. Between 2003 and 2012, just 100 were released, but in 2013 alone, 100 more joined them. Hugh Lewis of the University of Southampton in the UK and his colleagues have projected what might happen over the next 30 years if the rate of release reaches somewhere between 205 and 700 per year. They found that, even at the lowest rate, there could be as many as 16 million occasions when a CubeSat passes within 17 km of another object. Within a distance that small, unpredicted variations in orbits might lead to collisions. Lewis’s work has been criticized for overestimating the risk, but there is growing concern over the increasing popularity of ever-smaller satellites.