The U.S. Missile Defense Agency (MDA) is planning a second test of

an experimental satellite sensor that did not gather as much data as they would have liked during an initial test in August. That test was designed to gather data designed

to help them discriminate between the body and the exhaust plume of a ballistic missile,

according to the MDA official overseeing the effort.

MDA had planned to conduct a second test with the Near Field Infrared Experiment (NFIRE) in October, but postponed it to give

officials more

time to study what went wrong in August, according to U.S. Air Force Col. Christopher Pelc, program manager for the Space Tracking and Surveillance System and NFIRE efforts at MDA.

The next

demonstration will essentially be a repeat of the initial test, Pelc said. If the first test had gone off without a hitch, the agency might have pursued more advanced objectives in the second demonstration that had been scheduled for October, he said. MDA is planning to conduct the second demonstration

March 27, though that date could slip due to a busy manifest at Vandenberg Air Force Base, Calif., where the target will be launched, Pelc


The NFIRE satellite is built by General Dynamics Advanced Information Systems of Gilbert, Ariz. Mike Greenwood, a General Dynamics spokesman, declined to comment.

In a Jan. 8 interview, Pelc called the August test “a qualified success,” and said that the NFIRE spacecraft was able to collect some, but not all, of the data that the agency is looking for as it designs future missile tracking satellites.

The NFIRE was able to observe the target missile during the August test from a distance of just under 200 kilometers,

which enabled it to track the target, watch second-stage separation and view debris falling off the missile, Pelc said. Data gathered during the test was better than what the military has been able to do in this area with airborne sensors, and still will help address the plume and hard body discrimination issue as MDA develops future sensors, he said.

Losing track of the target was “really unfortunate, because everything else went very well,” Pelc said. The primary goal that was not achieved as a result was the ability to gather data from within about 20 kilometers of the target, he said.

The NFIRE demonstration was highly scripted, and the satellite lost track of the target missile due to problems synchronizing rocket telemetry databases on the spacecraft with those used on the ground, MDA officials said.

While the NFIRE satellite lost track of the target for only half a second, that time was significant because of the rocket’s velocity, Pelc said. The spacecraft was able to come within 3.5 kilometers of the target, but was only able to collect limited data by that point as it recovered from having lost track of the missile, the officials said.

The original plan for the NFIRE satellite included a second infrared sensor that would have been fired from the spacecraft aboard a missile defense kill vehicle in order to take a closer look at the target. MDA officials later acknowledged that it likely would have

unintentionally struck the target, prompting concerns from Democrats on Capitol Hill and critics of space-based missile interceptors that the experiment was intended to lay the ground work for the development of such systems. MDA ultimately dropped the kill vehicle from the NFIRE spacecraft.

Having the kill vehicle probably would not have helped maintain the track of the target because the plan for its use called for deploying it after the target’s third-stage separation, which occurred after the spacecraft already had

lost sight of the target, Pelc said.

The NFIRE satellite, which was launched in April 2007, has a two-year design life. The March demonstration will be the last dedicated missile test with the satellite, though MDA could observe other targets of opportunity at long distances, as it has to date with examples including a Russian Soyuz launch last fall, Pelc said.

There is also interest within the military in using the NFIRE satellite for the space situational awareness mission, Pelc said. While the spacecraft might not be as capable in monitoring objects on orbit as the Space-Based Visible Sensor on the Midcourse Space Experiment satellite, or the Space Tracking and Surveillance System demonstration satellites that are slated to launch later this year, it would give the military another chance to experiment with the use of infrared sensors for this mission, he said.