By Geoff Fein

The Navy will use a Standard Missile (SM)-3 launched from an Aegis-capable ship in the Pacific, in hopes of hitting an out of control spy satellite re-entering the Earth’s orbit, military and administration officials said yesterday.

The hope is to prevent the satellite, which is carrying a fuel tank full of hydrazine, from landing in populated areas, Marine Gen. James Cartwright, vice chairman of the Joint Chiefs of Staff, told reporters during a Pentagon briefing yesterday.

For the past three weeks, the Pentagon and NASA have been examining the best way to break-up the long-dead National Reconnaissance Office (NRO) satellite. The satellite lost power and went dead shortly after it obtained orbit in November 2006, Cartwright said.

At issue, Cartwright explained, is a tank of frozen hydrazine, a fuel used to conduct controlled de-orbits of working satellites, he said.

The gas could be toxic if the fuel tank landed in a populated area and dispensed its contents. The hydrazine onboard the satellite is frozen. Just how much would melt on re- entry is unknown.

Because of the toxicity of hydrazine and the fact that the satellite is on an uncontrolled re-entry led the government to opt for shooting the missile down.

Although Raytheon‘s [RTN] SM-3 is used as a defensive weapon in the Navy’s ballistic missile defense program, the missile to be used for taking out the NRO satellite will have its software heavily modified, Cartwright said. Lockheed Martin [LMT] builds the Aegis combat system, which also will be involved in the shot.

There are no plans to configure any other existing SM-3s to perform a similar mission, he said.

“This is a modified Standard Missile. It can’t co-exist with the current configuration. It’s a one-time deal,” Cartwright explained. “This is an extreme measure for this problem.”

The Navy is looking to fire a single SM-3 from a ship in the Pacific between Feb. 17-25.

“We will use one missile with two back-ups,” Cartwright said.

The Navy will have three ships on station somewhere in the Pacific in the northern hemisphere, during the shot, he added.

The Navy has seven destroyers and three cruisers that have the Aegis BMD (Ballistic Missile Defense) 3.6 configuration. Those ships have both the long-range surveillance and track capability as well as engagement capability. The Navy has seven additional surface combatants with just the long-range surveillance and tracking capability.

There have been questions whether the Pentagon would opt to shoot the spy satellite down because of its classified cargo. Cartwright said that was not a factor in the decision. An assessment of the satellite determined that there is high probability it would not be of any intelligence value.

“Just the heating…destruction that occurs on re-entry would leave it in a state that other than some rare unforecast happenstance, this would not be of intelligence value,” Cartwright said. “It’s the hydrazine that makes this different…makes it worthy of taking extraordinary measures.”

Once the SM-3 is launched, the Pentagon and the administration will have a two-day window for assessing whether the missile hit the satellite and either destroyed the hydrazine tank or broke the satellite into smaller pieces that will likely disintegrate upon re-entry.

“It’s a relatively small window,” Cartwright acknowledged.

He added that if a second SM-3 shot increases risk to a populated area, then the Navy won’t attempt it.

The planned SM-3 shot should not in any way be confused with a Chinese anti-missile shot in January 2007, Cartwright said, nor should it be seen as the U.S. beginning anti- satellite tests.

The Chinese shot down a missile that was 850 kilometers up and in a circular orbit, he said. That test left behind a debris field that will remain for decades.

If successful, the U.S. shot will occur at an altitude of 130 nautical miles above the Earth’s surface and the debris field will disperse in weeks or months, Cartwright said.

NASA Administrator Michael Griffin said the agency is not altering the Space Shuttle Atlantis‘ mission. “We expect to have the shuttle down before we have to engage,” he said.

“We looked at the increased risk to the shuttle and space station. [It is] negligible…not significant,” Griffin said. “There are good times to conduct the intercept due to the station’s location.”