Orbital Pegasus - Manual (Page 60)

Release 7.0 Apr 2010 49
Pegasus User’s Guide
7.1.1.2. Vehicle Integration and Test Activities
Figure 7-4 shows the Pegasus stages being
integrated horizontally at the VAB prior to the
arrival of the payload. Integration is performed at
a convenient working height, which allows easy
access for component installation, test, and
inspection. The integration and test process
ensures that all vehicle components and
subsystems are thoroughly tested before and after
final flight connections are made.
Figure 7-4. Pegasus Integration
Vehicle systems tests include a series of tests that
verify operation of all subsystems prior to stage
mate. The major tests are Vehicle Verification,
Phasing Tests, and Flight Simulations. For each
of these tests a specialized test software load is
installed into the Pegasus Flight Computer.
Vehicle Verification is a test that efficiently
commands all subsystems (fin actuators, TVCs,
FC discrete outputs, RCS, pyro commands, etc.)
in an accelerated time line.
Phasing tests verify the sign of the control loop of
the flight actuators and the dynamic operation of
the INS. In this test, the INS is moved manually
while the motion of the flight actuators (fins, TVCs,
and RCS) is observed and recorded.
Flight simulation testing uses the actual flight code
and simulates a “fly to orbit” scenario. All flight
actuators, pyro commands, and FC commands
are exercised. The Flight Simulation is repeated
after each major vehicle configuration change (i.e.,
Flight Simulation #1 after the motor stages are
built-up, Flight Simulation #2 after the motor
stages are mated, Flight Simulation #3 after the
payload is electrically mated/jumpered, and Flight
Simulation #4 after the payload is mechanically
mated). After each test, the configuration of the
vehicle is frozen until a full and thorough data
review of the test is complete, which usually takes
1 to 2 days. The payload nominally participates in
Flight Simulations #3 and #4.
In addition to these major tests, several other tests
are performed to verify the telemetry, flight
termination, accelerometer, and RF systems.
Pegasus integration activities are controlled by a
comprehensive set of Pegasus Work Packages
(PWPs), which describe and document in detail
every aspect of integrating Pegasus and its
payload. Pegasus Mission-Specific Engineering
Work Packages (EWPs) are created for mission-
unique or payload-specific procedures. Any
discrepant items associated with the test activities
are documented in Non-Conformance (NC)
Reports.
7.1.2. Payload Processing
For a launch at the integration site, a typical
Pegasus payload is delivered to the integration
site at launch minus 30 calendar days. If the
launch occurs at another location, the payload
may be required to be delivered up to 10 days
earlier to accommodate the additional ferry and
staging operations. The payload completes its
own independent verification and checkout prior to
beginning integrated processing with Pegasus.
Initial payload preparation and checkout is
performed by payload personnel prior to Flight
Simulation #3.
Payload launch base processing procedures and
payload hazardous procedures should be
coordinated through Orbital to the launch range no