Orbital Pegasus - Manual (Page 23)

Release 7.0 Apr 2010 12
Pegasus User’s Guide
orbit energy, or specific altitude and velocity
thresholds may be defined, which trigger
energy-scrubbing only in the event that the
thresholds are exceeded. The optimal
strategy for a particular mission will therefore
depend on the specific guidance objectives.
Figure 3-5. 3-sigma Injection Accuracies
Typical of Pegasus XL Missions
3.5. Collision/Contamination Avoidance
Maneuver
Following orbit insertion, the Pegasus Stage 3
RCS or HAPS will perform a Collision/Contam-
ination Avoidance Maneuver (C/CAM). The
C/CAM consists of a series of maneuvers
designed to both minimize payload contamination
and the potential for recontact between Pegasus
hardware and the separated payload.
Orbital will perform a recontact analysis for post
separation events. Orbital and the payload
contractor are jointly responsible for determination
of whether a C/CAM is required.
A typical C/CAM (for a non-HAPS configuration)
consists of the following steps:
(1) At payload separation +3 seconds, the launch
vehicle performs a 90° yaw maneuver
designed to direct any remaining Stage 3
motor impulse in a direction that will increase
Figure 3-4. Pegasus XL With HAPS Performance Capability