Washington, DC Dec. 13, 1997 – Following an intense ballet of threats and delay, Orbital Sciences Corp. late Thursday announced it had decided to modify the 4th stage of the Pegasus XL space booster awaiting launch from Vandenberg Air Base in California to comply with an FAA order.
As a result, the FAA has cleared the rocket for launch pending installation of a venting system to relieve post-launch pressures aboard the rocket. The FAA has grounded the winged booster until the changes were made.
Pegasus, carrying eight ORBCOMM satellites will now fly later this week. As
SpaceCast went to press Saturday, OSC officials were destacking the rocket
from its Lockheed L-1011 carrier aircraft for installation of the vent and
software control system.
FAA launch inspectors and Air Force officials at
Vandenberg were to monitor the changes, which will delay the launch several
days. The system will allow the rocket's computer to vent out excess
hydrazine fuel from the stage following shutdown in orbit high above the
California coast.
Officials were concerned that without such a relief
system, the excess fuel would gasify and build up pressure so severe that
the stage could explode in space, scattering pieces of orbital debris. OSC
officials said that they would comply fully with the FAA Associate
Administrator for Commercial Space's order in this and future launches of
the Pegasus launch vehicle.
