A satellite experiment planned for early 2007 could influence the design of a constellation of missile tracking satellites the Pentagon hopes to start launching around 2012, according to the Defense Department official managing both efforts.

The Near Field Infrared Experiment (NFIRE) is primarily intended to improve the navigation, guidance and control systems for new missile defense interceptors.

However, lessons from NFIRE could lead to improved sensors and communications links for the satellites being developed for the Space Tracking and Surveillance System (STSS) , according to U.S. Air Force Col. Christopher Pelc, who runs both programs for the Missile Defense Agency.

The NFIRE experiment is intended to help the Missile Defense Agency gather data that will be used to help future missile warning satellites discriminate between a ballistic missile’s fiery exhaust plume and the body of the rocket.

The NFIRE spacecraft is built by General Dynamics C4 Systems of Gilbert, Ariz., under a contract awarded in 2002.

If the NFIRE experiment goes well, it is unlikely the Missile Defense Agency would need to launch a follow-on spacecraft, but it is possible, partly because there is congressional interest in a follow-on mission, Pelc said in a Feb. 24 telephone interview.

The NFIRE spacecraft originally was designed to feature an infrared sensor to observe incoming missile targets during testing. The spacecraft also featured an additional sensor that would have flown near a missile target during testing to take a closer look.

The additional sensor was to be mounted on a kill vehicle developed for missile interceptors.

Opponents of space-based missile interceptors raised objections to the kill vehicle as a possible precursor to an operational system of space-based interceptors as well as space-based anti-satellite weapons, particularly once the Missile Defense Agency acknowledged that it would likely impact the target rocket.

The Missile Defense Agency might have avoided some of that controversy had it used a name other than “kill vehicle” for the additional sensor, which was included to allow a close look at the incoming rocket without risking damage to the NFIRE spacecraft, Pelc said. To compensate for not having the kill vehicle, the Missile Defense Agency will position the NFIRE satellite closer to the incoming rocket than previously planned, he said.

Some members of Congress, however, have been enamored of the kill vehicle concept, and included language in the 2006 Defense Appropriations Act encouraging the Missile Defense Agency to restore the kill vehicle to the experiment.

The Missile Defense Agency is unlikely to do so because completing the kill vehicle and integrating it onto the NFIRE spacecraft at this point would take at least two years, Pelc said.

After removing the kill vehicle from the NFIRE design, the Missile Defense Agency filled its spot with a laser communications payload built by Tesat-Spacecom of Backnang, Germany. The time it took the Pentagon to finalize that agreement with Germany and DoD’s desire for more capable software in the spacecraft contributed to the delay of the NFIRE launch from late 2006 into early 2007, Pelc said.

Laser payload

While it was not part of the initial NFIRE design and is not involved in the main missile defense experiments, the laser communications payload could benefit the Pentagon’s missile tracking mission, Pelc said. He noted that the use of laser cross-links between satellites will make it possible to move missile tracking information faster, particularly over long ranges.

The faster transmission speeds provided by the laser communications payload should help U.S. forces gather and distribute more data on an incoming missile, improving the probability of a successful intercept, Pelc said.

Evaluating the lessons learned from using the laser communications payload aboard NFIRE might take too long to include similar laser hardware aboard the first of the operational STSS satellites, which are referred to as STSS Block 12, Pelc said.

However, the laser hardware could be included on later blocks if the first NFIRE satellite shows laser communications to be an attractive option, he said.

Such an upgrade would be in keeping with the Missile Defense Agency’s strategy of making gradual improvements to its systems, he said. The ability to make incremental upgrades, known commonly as spiral development, is one of the reasons that the Missile Defense Agency is starting the STSS constellation with five satellites, Pelc said.

The agency previously had planned to acquire a constellation of 20 or more essentially identical missile tracking satellites under the Space Based Infrared System – Low program, which was restructured into STSS in 2002.

Another feature derived from the NFIRE experiment that could find its way onto the operational STSS constellation is a hyper-temporal sensor, Pelc said. This type of sensor could enable the missile tracking satellites to see the target missile before it penetrated cloud cover that can prevent infrared sensors from seeing the heat signature from a rocket launch, giving interceptor systems additional time to take aim, he said.

Giving troops manning interceptors even a few extra seconds to target a missile could prove especially useful during boost-phase intercepts, when the Pentagon would have only a brief time to attempt to shoot down the rocket, said Baker Spring, a defense analyst at the Heritage Foundation, a think tank here.

Improving the chances of a boost-phase intercept is particularly attractive because the missile is unable to use countermeasures that make shooting it down far more difficult, Spring said.

Before the Missile Defense Agency launches the operational STSS constellation, it plans to conduct a demonstration with two experimental satellites in 2007.

Northrop Grumman Space Technology of Redondo Beach, Calif., is the prime contractor for that effort, which is known as STSS Block 06, and Raytheon Space and Airborne Systems of El Segundo, Calif., is the subcontractor building the payloads, which were previously intended for a Space Based Infrared System – Low demonstration that was canceled in 1999.

Raytheon recently delivered the first of the experimental STSS payloads to Northrop Grumman, according to a Missile Defense Agency news release dated March 10. Air Force Lt. Gen. Henry “Trey” Obering, director the Missile Defense Agency, hailed the delivery in the news release as a “major milestone.”

The second payload is expected to be delivered to Northrop Grumman by the end of July, Pelc said.

Launching in 2007

Those two satellites are expected to be launched together aboard a Boeing Delta 2 rocket in late 2007.

Work on those satellites has progressed well since the STSS effort began in 2002, and the overall cost of the effort is within about 5 percent of the $868 million contract award given to Northrop Grumman in 2002, Pelc said.

The Missile Defense Agency awarded a $750 million contract modification to Northrop Grumman in 2004, but that money is for classified work that will follow the STSS Block 06 experiment, and not a cost overrun on the demonstration, he said.

The experimental satellites offer a missile tracking capability “far beyond” what sensors today are capable of handling, according to David Shingledecker, vice president for strategic systems at Raytheon Space and Airborne Systems.

While the STSS Block 06 satellites will not be able to provide continuous global coverage due to the limitations of having only two satellites in low Earth orbit, those satellites will support tests of the Ground Based Midcourse Defense System when they have favorable viewing locations, Pelc said.

The Missile Defense Agency also has two planned dedicated tests with the satellites against long-range ballistic missiles, and two dedicated tests against tactical missiles, Pelc said. Prior to testing the satellites against missiles, the Missile Defense Agency plans to use them to track aircraft and space objects to gain experience with the new sensors, he said.

The STSS Block 06 satellites also could have some operational missile tracking capability, and the Missile Defense Agency could position them in orbits designed for maximum coverage of areas like Iran and North Korea to best take advantage of the two satellites, Pelc said.

Meanwhile, the Missile Defense Agency is putting the finishing touches on the request for proposals for the operational constellation of STSS satellites, which must be approved by Obering before it can be released, Pelc said.

The agency anticipates awarding the contract for that work once it receives its 2007 budget — around Oct.1 or sometime thereafter if Congress encounters a delay in passing the defense appropriations legislation, Pelc said. Congress must approve of the acquisition plan. The plan was slowed in 2005 when Congress cut $500,000 from the STSS budget that would have funded early work on the operational constellation, he said.

The Missile Defense Agency is considering the possibility of awarding that work to Northrop Grumman on a sole-source basis, with a requirement that the company hold an open competition for the spacecraft payload, Pelc said.

Bob Bishop, a Northrop Grumman spokesman, declined to comment on the company’s plans for STSS follow-on satellites at this time.

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