Reluctant Reliance on Shuttles for Launching : Pentagon Satellite Schedule Disrupted

The Pentagon, which depends on the space shuttle to send vital national security satellites into orbit, is faced with an uncertain launch schedule pending the resumption of such flights after Tuesday’s mid-air explosion of Challenger.

Defense officials, who have been reluctant to commit their entire space program to the nation’s four shuttles, said Tuesday it was too early to determine the long-range impact that the destruction of one of them will have on the military use of space and the Pentagon’s reliance on the shuttle to launch its intelligence and communications satellites.

But the schedule for four more military launches this year--including one tied to the “Star Wars” program--has gone awry, and officials and others acknowledged that Challenger’s destruction could strengthen the Air Force’s efforts to use its own rockets to launch military satellites.

“Some of the launches are so valuable we have to have a system that guarantees it,” said one Air Force official, speaking on the understanding that he not be identified.

NASA Pact With Air Force

Under an agreement between the National Aeronautics and Space Administration and the Air Force--approved by President Reagan last year--the Pentagon was committed to using one-third of the shuttle flights to launch military satellites. These orbiters are employed for electronic eavesdropping, navigation and communications and for such direct military warning missions as spotting enemy missiles, bombers and combat preparations.

The Soviet Union depends exclusively on rockets to launch its satellites, although it is believed to be working on one and possibly two “space planes” bearing a striking resemblance to the shuttle.

The rocket used by the Air Force to launch military satellites is the Titan 34D7, built by Martin-Marietta Corp. Defense Secretary Caspar W. Weinberger last year directed the Air Force to buy 10 of them at a total cost of $2.09 billion.

Before the loss of Challenger, the shuttle Discovery was scheduled to break in the launch pad at Vandenberg Air Force Base in July, carrying a mission for the Strategic Defense Initiative, commonly known as the “Star Wars” missile defense research project. The goal of that mission was to measure infrared light in space, a necessary step toward spotting infrared emissions from enemy missiles.

The Discovery was also scheduled to carry out a mission, code-named “Teal Ruby,” to help the Air Force track enemy bombers. But some experts consider this project less urgent than others and therefore a possible candidate for postponement in a revised launch schedule.

Subsequent military shuttle missions were to be carried aboard the Columbia, to be launched from the Kennedy Space Center in September; aboard Discovery, to be launched later that month from Vandenberg; and aboard the Challenger, which was scheduled to begin a flight in December from Florida.

The Vandenberg flight in September was scheduled to carry a photo reconnaissance satellite and a Defense Satellite Communications System, which is intended to provide communication links between military command centers and U.S. forces around the globe, according to John Pike, a space weapons expert on the staff of the Federation of American Scientists.

As a result of the Challenger explosion, however, this military schedule is being examined and will probably be delayed, just as the timetable for commercial use of the shuttle has been thrown into uncertainty.

“The impact depends upon how long the investigation takes,” said Air Force Col. Robert J. O’Brien Jr., a Pentagon spokesman. “It’s too early to make that assessment.”

Air Force Argument

The Air Force, in arguing for a continued capability to launch satellites atop Titan rockets--known as “expendable launch vehicles”--maintains that it must be able to send orbiters into space at almost a moment’s notice if, for example, one of the many satellites scattered across the skies should suddenly fail and create a gap in the net that monitors Soviet space launches.

Noting that the Air Force has been given the go-ahead to buy these rockets, Paul B. Stares, a research associate at the Brookings Institution and author of “The Militarization of Space,” said that the explosion of Challenger and the likely shuttle delays “will add grist to those who say we need emergency launch capabilities to put satellites into space on short notice.”

However, he said, “I can’t conceive that anybody will start pulling out of the shuttle program as a result.”

In testimony last March before the House Appropriations subcommittee on defense, Air Force Undersecretary Edward C. Aldredge Jr. said the Air Force rocket “will serve as a hedge against any (shuttle) technical and operational problems and will improve our ability to operate in crisis and conflict situations short of direct attack on the U.S.”

Aldredge, whose responsibilities include the Air Force participation in the space program, has been spending increasing amounts of time at the Johnson Space Center in Houston, preparing for the first shuttle flight launched from Vandenberg.

The dispute between NASA and the Air Force was said by one Pentagon official to have been “pretty much worked out.” But, he said, it could be reopened, depending upon the impact of the space agency’s loss of “25% of its launch capability.”