In an expensive technical mishap, a brace of top-secret American spy satellites was fired into incorrect orbits last Friday.

According to a report in Aviation Week and Space Technology, the two spacecraft in question were ultra-classified ocean surveillance jobs, described as "critical to tracking ships that may conceal al Qaeda terrorists...[or] Iranian and Chinese sea-based military operations".

Perhaps vessels from other nations, too. The North Korean ship So San, seized with a hidden cargo of Scud missiles in the Indian Ocean during 2002, was said to have been tracked by US intelligence since leaving home (the ship was later allowed to proceed to Yemen, after US officials acknowledged that the Yemenis were allowed to buy Scuds concealed under bags of cement if they felt like it).

Whatever it is the US National Reconnaissance Office (NRO) does with its secret spy sats, these two will apparently struggle. According to Aviation Week and Space Technology, the Centaur second stage of the Atlas V launcher failed to make its second positioning burn correctly. The two surveillance birds reached an orbit, but not the intended one.

It seems the two spacecraft may have to use a significant proportion of their manoeuvring fuel to get into a useful position, which would seriously affect their service life. Spy satellites need to change track over the Earth's surface fairly frequently in order to get a good look at areas of interest.

Aviation Week and Space Technology quotes an unnamed official as saying that "the Atlas V people have a lot of explaining to do".

The Atlas launch programme is managed by United Launch Alliance, and this was the first use of the Atlas V Evolved Expendable Launch Vehicle to position secret NRO satellites. The Centaur upper stage, which was apparently at fault, comes from Lockheed Martin and uses a Pratt & Whitney rocket engine.

More from Aviation Week and Space Technology here. ®

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