02.14.09

Iridium collision: NASA ties itself in knots

Posted in Iridium at 10:31 am by timfarrar

There continues to be confusion about who said what to whom and when. Iridium stated emphatically on Thursday that “it had no advance warning of the impending collision”. However, Nicholas Johnson, NASA’s chief scientist for orbital debris, was quoted in a Washington Post article on Friday afternoon as saying “Iridium, the Bethesda-based satellite phone company, had received a report that its satellite — one of 66 used in its communications network — would pass within 300 meters of the non-operational Cosmos. Instead, the Iridium suddenly went silent. Soon thereafter, the military picked up on its radar indications of debris in orbit over Siberia. The improbable had finally happened.”

Curiously enough this quote was removed from the final printed version of the article, and Mr Johnson had previously noted that Iridium wasn’t on the top 10 list of most likely collisions on Tuesday, while the US Defense Department has been quoted as saying it did not predict the collision.

While the trading of accusations may continue for some time, it seems increasingly likely that the problem will turn out to be due to some unanticipated modeling error in the orbit prediction programs used by both military and civilian operators. Its pretty certain that this will lead to calls for more funding of space observation networks, to avoid any future problems. As a minimum, better data, and more sharing of the data that does exist, needs to be high on everyone’s agenda.

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