How well can the military estimate satellites orbits?
That’s not clear, as the Pentagon may not release its best estimates of satellite orbits. But space analysts say the data the Pentagon does make publicly available is not precise enough to accurately estimate the probability that two objects might collide. Tuesday’s smashup is a case in point. Using a collision prediction program to perform a retroactive analysis of the satellites’ orbits, aerospace analyst T S Kelso found that the Pentagon’s public data showed that the two satellites would have missed each other by 584 metres. But he says the uncertainty in that distance could be several kilometres. “There’s no reason looking at the data that was available [to think the Russian satellite] was an immediate threat,” says Kelso, who has been working with Iridium to assess the risk that the debris could collide with other satellites in the firm’s fleet (see image above right). Could Iridium have predicted a collision? Since Iridium likely communicated directly with its now-destroyed space
