Orbital Antares - Manual (Page 33)

Antares
®
OSP-3
User’s Guide
Section 4.0
– Payload Environments
Release 1.1 July 2013 22
Table 4.1.1-2 provides the primary dynamic loading events and the time phasing of these events during
Antares flight. Pyroshock events are not indicated as they do not occur simultaneously with any other
significant dynamic loading events.
Table 4.1.1-2. Phasing of Dynamic Loading Events
Item Liftoff Transonic
Supersonic/
Max Q
S2 Ignition S2 Burnout
Typical Flight Time 2 sec 79 sec 90 sec ~330 sec ~485 sec
Steady State Loads Yes Yes Yes No Yes
Transient Loads Yes Yes Yes Yes No
Acoustics Yes Yes Yes No No
Random Vibration Yes Yes Yes No No
As dynamic response is largely governed by payload characteristics, multiple mission-specific CLA are
performed, with customer-provided finite element models of the payload and different states of definition.
Flight events analyzed by the CLA include liftoff, the transonic portion of flight, supersonic flight, Maxi-
mum Dynamic Pressure (Max Q), MECO, and Stage 2 ignition. Results are documented in the mission-
specific ICD.
Orbital performs two CLAs for each mission. The preliminary CLA is based on the analytical payload
models. The final CLA is based on the test-verified payload model.
4.1.2. Payload Acceleration as a Function of Mass
Payload mass affects the maximum axial quasi-static acceleration a specific payload experiences. Fig-
ures 4.1.2-1 through 4.1.2-6 provide the vehicle quasi-static acceleration as a function of payload mass
for all configurations.