WASHINGTON — The failed U.S. spy satellite now slowly falling back to Earth was designed to demonstrate a new and unique blend of optical and radar imaging capabilities, according to an intelligence community source familiar with the project.

“It’s terrible, because this was a special, special capability,” this


told Space News. It was an “imaging satellite class, but it may not be optical or radar alone,” the

source said. The spacecraft, built by the Advanced Systems and Technology Directorate of the U.S. National Reconnaissance Office (NRO),

contains a “telescope-like capability,” the source said.

It was

not directly connected to


Future Imagery Architecture

, the source said.

The satellite, dubbed U.S. 193, launched Dec. 14, 2006, from Vandenberg Air Force Base, Calif., aboard a Boeing Delta 2 rocket. But the spacecraft “never really initialized” and the NRO never learned what went wrong, the source said.

“We really don’t know what happened. We just lost contact with it on its third orbit.”

Ted Molczan, an amateur satellite tracker in Canada who has watched U.S. 193 since its launch, said the satellite’s orbit

suggested it was intended for either optical or radar imaging.

“The orbit suggests radar more to me than optical

” because it is closest to those traditionally used by the NRO’s radar imaging behemoths

, Molczan said Jan. 31.

It was not placed into Sun

synchronous orbit

, which is where most optical imaging satellites operate, he said.

U.S. 193’s orbit was inclined at

58.5 degrees relative to the equator, Molczan said

. “That orbit is kind of consistent with the idea there was a tradeoff in capabilities” between optical and radar, he said.

A congressional aide said Jan. 31

the satellite was

expected to fall to Earth around mid-February. Molczan said he thought late March was a more likely date, based on the rate of decay of the satellite’s orbit. The intelligence community source said the satellite weighs

between 4,000 and 4,500 kilograms, or about half the weight of one of the NRO’s operational radar spacecraft


The intelligence community source, along with another source

familiar with the program, said the majority of the satellite should burn up as it re-enters the

atmosphere. Some titanium or tungsten pieces may survive and

pose a small risk, they said.

The satellite also contains hydrazine, an extremely toxic fuel, and some analysts have voiced concern this could pose a threat should it not burn up in the atmosphere during reentry. However, the two sources familiar with the program said that

possibility is remote. If the hydrazine tank is punctured or melts during

re-entry all the fuel should burn away, those sources said.


intelligence community source also said nothing should survive that might reveal the satellite’s capabilities. In particular, the telescope-like sensor and its mirrors

are certain to be destroyed

, the source said.

Rick Oborn, NRO spokesman, declined to comment.

Gordon Johndroe, a spokesman for the White House National Security Council, said Feb. 1 the “appropriate government agencies are monitoring the situation. Numerous satellites have come out of orbit and fallen harmlessly. We are looking at potential options to mitigate possible damage this satellite may cause.”