Orbital Pegasus - Manual (Page 61)

Release 7.0 Apr 2010 50
Pegasus User’s Guide
later than 120 days prior to first use (draft) and 30
days prior to first use (final).
7.1.2.1. Ground Support Services
The payload processing area capabilities depend
on which mission option is chosen based on
launch site: integrate and launch; integrate, ferry,
and launch; or Pegasus campaign to launch site.
Payload-unique ground support services are
defined and coordinated as part of the MIWG
process.
Vandenberg ground support services that would
be used in the launch and ferry scenarios are
outlined in Appendix B.
7.1.2.2. Payload to Pegasus Integration
The integrated launch processing activities are
designed to simplify final launch processing while
providing a comprehensive verification of the
payload interface. The systems integration and
test sequence is engineered to ensure that all
interfaces are verified after final connections are
made.
7.1.2.2.1. Pre-Mate Interface Testing
The electrical interface is verified using a mission-
unique Interface Verification Test (IVT), in
conjunction with any payload desired test
procedures, to mutually verify that the interface
meets specifications. The IVT and payload
procedures include provisions for testing the LPO
interfaces, if necessary.
If the payload provider has a payload simulator,
this test can be repeated with this simulator prior
to using the actual payload. These tests,
customized for each mission, typically checkout
the LPO controls, launch vehicle sequencing, and
any off-nominal modes of the payload.
When the payload arrives at the integration site,
Pegasus components can be made available for a
preliminary mechanical interface verification
before final payload preparations. After “safe-to-mate” tests, the payload is
electrically jumpered, and further interface testing
(e.g., data flow between the spacecraft and the
Pegasus) is performed, if necessary. Flight
Simulation #3 is then performed, using a flight
MDL, INS simulator, and other EGSE. For
payloads with simplified interfaces to the Pegasus,
it may be acceptable to proceed to payload mate
and the final Flight Simulation, immediately after
the IVT.
7.1.2.2.2. Payload Mating and Verification
Once the pre-mate payload closeouts are
completed, the payload will be both mechanically
and electrically mated to the Pegasus. Following
mate, the flight vehicle is ready for the final
integrated systems test, Flight Simulation #4, in-
flight configuration. One of the last two flight
simulations is performed on the flight batteries.
This test is in full flight configuration (internal
power, firing RCS, etc.), but without ordnance
connected, allowing a complete check of all
interfaces after mating the payload, while
minimizing the payload time on the vehicle before
launch. The integrated test procedures are
developed by the LOWG and reviewed by the
appropriate payload, launch vehicle, and safety
personnel.
7.1.2.2.3. Final Processing and Fairing Close-
Out
After successful completion of Flight Simulation
#4, all consumables are topped off and ordnance
is connected. Similar payload operations may
occur at this time. Once consumables are topped
off, final vehicle/payload closeout is performed,
and the payload fairing is mated. Integrated
system tests are conducted to ensure that the
Pegasus/payload system is ready for launch.
7.1.2.2.4. Payload Propellant Loading
Payloads utilizing integral propulsion systems with
propellants such as hydrazine can be loaded and
secured through coordinated Orbital, Government,
and payload contractor arrangements for use of