WASHINGTON — The next space shuttle launching, originally set for July, 1987, has been rescheduled to early 1988 at best because of delays in redesigning the solid rocket booster that caused the Challenger disaster, NASA Administrator James C. Fletcher said Monday.
Hours after delivering a 50-page progress report to President Reagan, Fletcher said at a news conference that NASA has "a good running start on recovery" from January's shuttle explosion, which killed seven crew members and brought the space program to a standstill.
He also denied that the Challenger disaster signaled the United States' loss of space leadership to the Soviet Union, which has continued to ferry cosmonauts to a prototype space station while the shuttle has been grounded. An American space station--the next big step in the U.S. space program--will not be assembled until the early 1990s.
Satellite Backlog Seen
Fletcher conceded, however, that the new shuttle launching delay, extended from 18 months to more than two years, will add to a massive backlog of satellites and other payloads waiting to ride into space.
And he said it remains unclear whether the White House can provide the $2-billion-plus needed to replace Challenger without drastically curtailing NASA's other space endeavors--an alternative Fletcher called unacceptable.
"I think financing is the principal issue," he said. "I'm not sure that I want to go ahead with a fourth orbiter if it comes out of other NASA programs."
The issue was discussed "in some depth" with Reagan on Monday, Fletcher said, but without solution. The White House said a decision on building another orbiter will not be made for at least two weeks.
In the report to Reagan, Fletcher said that NASA is "vigorously" implementing nine recommendations made last month by the presidential commission that investigated the shuttle accident, which called for an overhaul of space agency management and improvement of spaceflight safety.
He called the launching delay "one negative piece of news" in an otherwise upbeat assessment of the agency and noted that "the high priority of safety" was behind the decision to postpone the shuttle's return to space.
Former astronaut Richard H. Truly, NASA's associate administrator for spaceflight, said that the launching postponement was caused by unexpected difficulties in tooling and fabricating a molded insulation section of the joints that link the huge, barrel-shaped segments of the shuttle's two solid rocket boosters.
It was a hot-gas leak in one of those joints that caused Challenger's main liquid fuel tank to explode last Jan. 28, barely 73 seconds after liftoff.
"The more we looked at the difficulty of those tooling designs . . . we just couldn't get" to a launch by July, 1987, Truly said.
Engineers are confident that the proposed changes in the rocket joints can be made and tested by 1988 and that they will prevent future leaks, he said, but the agency is drafting plans for a completely different rocket design in case unexpected problems develop.
A "conservative" NASA schedule allows the shuttle to return to space sometime in the first quarter of 1988, Fletcher said, although even that timetable could slip. Nevertheless, he called Monday's report "a road map . . . to get back to flying again."
Under timetables released Monday, a complete review of every critical component in the shuttle will be finished by next May, and the new design for the shuttle's solid rocket boosters will be tested and fully certified in December, 1987.
Among other efforts to act on the presidential commission's findings, NASA will finish studies of agency management and internal communications, replace troublesome brakes on the shuttle's landing gear, review flight schedules and maintenance programs and take a second look at landing sites around the globe where the shuttle could land in case of emergency.
Use of Soft Barriers
The agency is studying the installation of soft barriers at many landing strips, including the one at the Kennedy Space Center, Fla., to help brake a shuttle that is forced to land on a short runway.
In addition, NASA is searching for ways to reduce the high risks of an emergency landing, including a method to separate the orbiter from its fuel tank and rockets without subjecting the spacecraft to aerodynamic stresses that would break it up.
Of one key recommendation, Truly said that it "is probably impossible" to devise a method that would allow shuttle astronauts to escape in an emergency during the launching.