Orbital Antares - Manual (Page 17)

Antares
®
OSP-3
User’s Guide
Section 2.0
– Overview
Release 1.1 July 2013 6
2.2.2.2. Stage 2 Avionics Module
The Antares avionics design incorporates Orbital’s latest MACH design technology to provide power
transfer, data acquisition, booster interfaces, and ordnance initiation. This advanced system supplies the
increased capability and flexibility required by the Antares to communicate with vehicle subsystems, GSE,
and the payload utilizing standard Ethernet links and discrete Input/Output (I/O).
2.2.3. Payload Accommodations
Antares payload accommodations include a fairing and the USAF standard non-separating mechanical
interface. The spacecraft interface can be enhanced with a variety of payload separation systems.
2.2.3.1. Payload Fairing
Antares employs a 3.9 m (155 in.) composite bi-sector fairing (Figure 2.2.3.1-1) consisting of two graphite
composite shell halves and associated separation systems. The two fairing halves are joined with a fran-
gible rail joint, and the base of the fairing is attached
to Stage 2 using a similar ring-shaped frangible
joint. Severing the rail/ring frangible joints allows
each half of the fairing to rotate on hinges mounted
on the Stage 2 fairing cylinder. A cold gas system is
used to drive pistons that force the fairing halves
open. All fairing deployment systems are non-
contaminating.
With a fairing volume greater than 57.5 m
3
(2,031
ft
3
) available for users, Antares provides significantly
greater volume for accommodating payloads than
any other Medium-Class launch vehicle in produc-
tion. The payload design envelope for the Antares
fairing ensures adequate static and dynamic clearances to the payload assembly are maintained during
ground operations and ascent. The static and dynamic payload envelopes provided by Antares fairing
are detailed in Section 5.
2.2.3.2. Payload Interface
Under OSP-3, Orbital offers a non-separating interface for the customer as well as a variety of separation
systems as enhancements. The standard payload interface for Antares for OSP-3 missions is a 1575 mm
(62 in.) bolt circle common with the Evolved Expendable Launch Vehicle (EELV) interface standard. This
non-separating mechanical interface accommodates all Orbital-provided payload separation system en-
hancements and can accommodate customer-provided payload adaptors and separation systems. De-
tails of the available non-separating mechanical interface and optional payload separation systems are
presented in Sections 5 and 8, respectively.
Figure 2.2.3.1-1. Antares 3.9 m Fairing
Assembly