Orbital Minotaur I - Manual (Page 19)

Minotaur I User’s Guide Section 2.0 – Minotaur I Configurations
Thrust Vector Control (LITVC) subsystem, S2
ignition safe/arm device, a Roll Control System
(RCS), and the Stage 2 MMODS FTS
components. Attitude control during second stage
burn is provided by the operational LITVC and hot
gas roll control.
2.3.2. Upper Stack Assembly
The Minotaur I Upper Stack is composed of the
Stage 3 and 4 motors, their associated
interstages, the avionics assembly, and,
ultimately, the payload and payload fairing. The
Stage 3 and 4 motors are the Orion 50 XL and
Orion 38, respectively. These motors were
originally developed for Orbital’s Pegasus
program and are used in a similar manner on the
ground-launched Minotaur I vehicle. Common
design features, materials and production
techniques are applied to both motors to
maximize reliability and production efficiency. The
motors are fully flight qualified based on their
heritage, conservative design, ground static fires
and over 60 launches. Processing of the
Minotaur I Upper Stack is conducted at the
Minotaur Processing Facility (MPF), as shown in
Figure 2.3.2-1.
2.3.2.1. Avionics
The Minotaur I avionics system has heritage and
commonality across the Minotaur fleet. The flight
computer is a 32-bit multiprocessor architecture. It
provides communication with vehicle subsystems,
the LSE, and if required, the payload via standard
RS-422 serial links and discrete I/O. The avionics
system design incorporates Orbital’s innovative,
flight proven Modular Avionics Control Hardware
(MACH). The MACH consists of standardized,
function-specific modules that are combined in
stacks of up to 10 modules to meet mission
requirements. The functional modules from which
the MACH stacks are created include power
transfer, ordnance initiation, booster interface,
communication, and telemetry processing. These
modules provide an array of functional capability
and flexibility.
Figure 2.3.1-1. Minotaur I LSA Being Lifted out
of Transporter Erector
Figure 2.3.2-1. Minotaur I Upper Stack
Assembly Processing at Orbital’s Minotaur
Processing Facility at VAFB
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