ARG%SU-AI@sri-unix.UUCP (07/20/83)
From: Ron Goldman <ARG@SU-AI>
a019 2325 19 Jul 83
PM-Space Shuttle,480
Next Two Shuttle Flights Might Be Postponed
By HOWARD BENEDICT
AP Aerospace Writer
WASHINGTON (AP) - The next two space shuttle flights may have to be
delayed because of new problems in checking out a trouble-plagued
communications satellite, the head of the shuttle program says.
''We're looking carefully at the whole thing,'' Lt. Gen. James A.
Abrahamson said Tuesday. ''We will not make a decision for a while. It
may well be that we can turn this whole thing around and everything
will be fine.''
The National Aeronautics and Space Administration has been working
toward an Aug. 20 launch date for the eighth shuttle flight and Sept.
30 for No. 9, which will carry the European-built Spacelab, a $1
billion research facility.
Abrahamson said the eighth mission, packing a communications
satellite for India, might be put off a few days until the Tracking
and Data Relay Satellite, called TDRS, is ready for communications
tests by the astronauts on that flight.
''With the exception of TDRS, the Aug. 20 launch date is looking
good,'' Abrahamson said.
TDRS is essential for high-speed data transmission from Spacelab,
and will require additional checkouts before it can support that
mission. NASA has only a one-week period starting Sept. 30 to launch
the lab for maximum effect. If the satellite is not ready in time, the
flight would have to slip until the next available launch
opportunity, which starts Oct. 26, Abrahamson said.
The 10th flight, a secret Defense Department mission which also
depends on TDRS, earlier was delayed indefinitely because of the
satellite's troubles.
The troubles started when TDRS was launched from the shuttle
Challenger on April 4, and an attached rocket engine misfired, kicking
it into a too-low orbit. Using the payload's small jets, engineers
finally elevated it to a proper orbit 22,300 miles up on June 29 and
began checkouts of the complicated system.
The latest problems have not been in space, but at the TDRS ground
station at White Sands, N.M., which is billed as one of the most
sophisticated satellite tracking facilities in the world.
Engineers recently found their computers were failing to command the
huge satellite to lock its antennas onto White Sands. That problem,
in computer programs, was corrected Friday.
On Monday, there was an interruption in the electrical power to the
White Sands station, followed by a failure in the backup generator
system.
White Sands has three 625 kilowatt backup generators and needs two
to operate the facility when commercial power fails. When the outage
occurred, one of the generators was down for servicing and a second
failed.
Later in the day there was a second interruption in commercial power
and, with only one generator working, no work could be done with the
satellite. That delayed the already tight checkout by a day and a
half.
ap-ny-07-20 0227EDT
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