![[ image: width=150]](/olmedia/315000/images/_315328_titan4aexplosion150.jpg)
The $250m Defence Support Programme satellite went up without a hitch from Cape Canaveral on Friday on board the unmanned Titan 4B rocket.
But a spokeswoman for the satellite's control centre at Schriever Air Force Base in Colorado said: "The satellite was not placed in its required geosynchronous orbit."
She said two rocket firings required to position the satellite did occur but it had still failed to find its correct orbit 19,320 miles above the equator.
It is now travelling on an egg-shaped loop around Earth.
The spy satellite and its rocket together are estimated to have cost about $682m.
The latest mishap follows an explosion that destroyed the latest rocket's predecessor, Titan 4A, and its satellite cargo shortly after launch last August.
Archive of last August's explosion
That accident was estimated to be one of the most expensive space disasters yet, costing approximately $1bn.
Schriever Air Force Base said it was "looking at every angle possible to see what can be done to salvage the satellite".
Similar satellites have been watching over the Balkans as Nato conducts air strikes against Yugoslavia. The network was also used extensively during the Gulf War to spot Iraqi Scud missile launches.
They are designed to detect missile launches and nuclear detonations by using an infrared sensor to detect heat from missile and booster plumes against the Earth's background.
Big rocket success
(11 Apr 99 | Sci/Tech)
$1bn up in smoke
(12 Aug 98 | Americas)
US Airforce Space Command
Lockheed Martin Corp
Floriday Today - Titan 4A Failure
The BBC is not responsible for the content of external internet sites.
World's smallest transistor
Scientists join forces to study Arctic ozone
Mathematicians crack big puzzle
The growing threat of internet fraud
(From Business)
Who watches the pilots?
Cold 'cure' comes one step closer
(From Health)