Delta IV Heavy Rocket to Cross Paths with Space Shuttle

This story was updated at 6:35 p.m. EST.

The U.S. Air Force plans the first operational use of a new rocket Nov. 8, when it launches the last of the current generation of U.S. missile warning satellites aboard the largest version of the Delta 4 Evolved Expendable Launch Vehicle.

The Defense Support Program (DSP)-23 spacecraft currently is targeted for launch at Cape Canaveral, Fla., on Nov. 8, according to Lt. Col. Joe Coniglio, the Air Force's DSP program manager. The space shuttle is due to return to Earth on Nov. 7, and Coniglio said during a Nov. 1 interview that the priority given to the manned mission could cause the launch of the missile warning satellite to slip by a day or two.

According to the Cape Canaveral Air Force Station, the Delta 4 launch could occur on Nov. 10.

The DSP satellite, which was built by Northrop Grumman Space Technology of Redondo Beach, Calif., will ride on the heavy-lift variant of the Delta 4 rocket built by United Launch Alliance. That rocket had failed to put its payload in the right orbit during a demonstration launch in December 2004 when an errant sensor reading caused its engines to shut down early, contributing to more than two years of delay in the launch of DSP-23.

Coniglio said investigative work conducted following the demonstration has thoroughly addressed the issues that led to the problems, and that he is confident in the Delta 4 heavy's ability to launch DSP-23.

In one case of past launch difficulty, DSP-19 was put in the wrong orbit following its launch in April 1999, according to Peggy Paul, Northrop Grumman's DSP program manager. While the Air Force was not able to use it for missile warning, the satellite's twice-daily orbits through the Van Allen belt yielded valuable data for scientific and parts reliability purposes, she said.

Coniglio declined to comment on the impact to the Pentagon's missile warning capability if DSP-23 were to be lost in a launch mishap or fail on orbit. However, he noted that the DSP constellation is healthy, and that the satellites have far outlived their design life.

Northrop Grumman has been able to help extend the life of the satellites through adding additional fuel, improving the efficiency of fuel and battery consumption, and determining precisely when the satellites need to be boosted in super-synchronous orbit, Paul said.

Coniglio noted that the DSP has launched on several iterations of the Titan rocket over its 37-year history, as well as aboard the space shuttle. In the case of Titan 4A and Titan 4B, DSP was the inaugural payloads on those rockets, as is the case with the Delta 4 heavy, he said.

In addition to their primary role of scanning the Earth to watch for ICBM launches, the DSP satellites have played a role in tactical operations beginning with the Persian Gulf War in 1990.

Data from the satellites has been used to provide warning of smaller rockets like the Scuds launched against U.S. troops in the Middle East through upgrades to ground processing systems, Coniglio said.

In addition to their primary infrared sensor, the DSP satellites also host a sensor suite designed to detect nuclear blasts. DSP-23 carries this sensor package, as well as an experiment called the Space and Atmospheric Burst Reporting System (SABRS) Validation Experiment (SAVE), which is intended to demonstrate new technology for future nuclear detection payloads that could enable capabilities like smaller sensor suites, Coniglio said.

Coniglio said he was grateful that, with satellite work winding down and the last DSP launch delayed by more than two years, key industry staff did not retire or choose to move onto other positions. He said that kind of commitment and dedication on the part of military, Aerospace Corp. and Northrop Grumman personnel throughout the program's history have been a big key to its success.

Even after the launch, the program will continue to need staff for operational support, he said.