Orbital Pegasus - Manual (Page 63)

Release 7.0 Apr 2010 52
Pegasus User’s Guide
countdown procedure. The Orbital Vehicle
Engineer has the overall responsibility for the
Pegasus launch vehicle. A team of engineers,
which reviews the telemetry to verify that the
system is ready for launch, support the Vehicle
Engineer. The range status is coordinated by the
Range Control Officer who provides a Go/No-Go
status to the LC.
The third group is the Airborne Operations Group,
which includes the LPO and the aircraft crew. The
LPO monitors on-board systems from the launch
panel station on-board the carrier aircraft and
executes on-board countdown procedures. The
aircraft crew operates the aircraft, achieves proper
pre-release flight conditions, and activates the
actual physical release of the Pegasus vehicle.
7.1.3.4. Flight Activities
The launch checklist begins prior to OCA engine
start and continues until after Pegasus is released.
All members of the launch team and the aircraft
crew work from this procedure. Abort procedures
and emergency procedures are also contained in
the launch notebooks.
At the Hot Pad, about 1 hour before T.O., the FTS
power is turned on and all inhibits are verified, the
S&A safing pins are removed, and the vehicle is
placed in a ready state. At this time the aircraft
and the Pegasus are ready for T.O.
Orbital arranges for Pegasus telemetry and
tracking services during captive carry and
Pegasus powered flight. Data will be passed to
the payload mission control console as determined
by the MIWG process.
Once airborne, Pegasus is configured into a
launch condition by switching the FTS to internal
battery power at approximately L-10 minutes, the
avionics bus to internal power at approximately
L-7 minutes, and the transient power bus to
internal power at approximately L-3.5 minutes. If
Figure 7-5. Typical Pegasus Launch Checklist Flow