USA 193 Intercept

Popular in the sensational space news spotlight last week was the Navy’s shootdown of satellite USA 193, internally known as NROL-21, an experimental reconnaissance satellite which suffered post-launch computer failure so it was trapped in a rapidly decaying low earth orbit, and could have crashed with many large parts intact. Carrying a full tank of highly toxic hydrazine, USA 193 may have posed the greatest reentry threat since Skylab and Cosmos 954 — not to mention the [officially denied] possibility of classified reconaissance hardware surviving reentry and falling into the wrong hands. Without a working guidance system on the satellite, DoD decided to disrupt it with a missile, fragmenting it into smaller pieces which would burn up in the atmosphere, and hopefully rupture the fuel tank to disperse the hydrazine before reaching the ground.

DoD announced the mission on February 14th, and launched an SM-3 missile with a non-explosive kinetic warhead on February 21st from the USS Lake Erie in the Pacific — during the lunar eclipse, interestingly enough. The missile hit the satellite, and an explosion was recorded, with several small fragments reentering the atmosphere shortly after, and a small number of other pieces in orbit being tracked. It was a surprisingly efficient one-shot operation: going from notification of the threat to announcement of the mission in less than a month, and from there to a successful strike on an orbital target in just a week. That’s impressive turnaround time for a process of transforming a catastrophic billion-dollar satellite failure into a public relations semi-triumph of James-Bondian technological scope.

More info on the USA 193 operation: