Orbital Minotaur I - Manual (Page 33)

Minotaur I User’s Guide Section 4.0 – Payload Environment
4. PAYLOAD ENVIRONMENT
CAUTION
The predicted environments provided in this user's guide are for initial planning
purposes only.
Environments presented here bound a generic mission and should not be used in
mission specific analyses. Mission specific levels are provided as a standard
service and documented or referenced in the mission ICD.
This section provides details of the predicted environmental conditions that the payload will experience
during Minotaur ground operations, powered flight, and launch system on-orbit operations. The predicted
environments provided in this user’s guide are for initial planning purposes only.
Minotaur ground operations include payload integration and encapsulation within the fairing, subsequent
transportation to the launch site and final vehicle integration activities. Powered flight begins at Stage 1
ignition and ends at Stage 4 burnout. Minotaur I post-boost operations begin after Stage 4 burnout and
end following payload separation. To more accurately define simultaneous loading and environmental
conditions, the powered flight portion of the mission is further subdivided into smaller time segments
bounded by critical flight events such as motor ignition, stage separation, and transonic crossover.
The environmental design and test criteria presented have been derived using measured data obtained
from many difference sources, including data from previous flights, motor static fire tests, and other
Orbital system development tests and analyses. These criteria are applicable to Minotaur I configurations
using both the standard 50 in. and optional 61 in. diameter fairing. The predicted levels presented are
intended to be representative of a standard mission. Payload mass, geometry and structural components
vary greatly and will result in significant differences from mission to mission.
Dynamic loading events that occur throughout various portions of the flight include steady state
acceleration, transient low frequency acceleration, acoustic impingement, random vibration, and
pyrotechnic shock events.
4.1. Steady State and Transient Acceleration Loads
Design limit load factors due to the combined effects of steady state and low frequency transient
accelerations are largely governed by payload characteristics. A mission-specific Coupled Loads Analysis
(CLA) will be performed, with customer provided finite element models of the payload, in order to provide
precise load predictions. Results will be referenced in the mission specific ICD. For preliminary design
purposes, Orbital can provide initial CG netloads given a payload’s mass properties, CG location and
bending frequencies.
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