A Case Study in NASA-DoD - The Black Vault

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lateral and angular alignment once the spacecraft mass properties have
been determined.
The instrument module contains the mission instruments and the
supporting electronics. This module is connected by low-heat-conduction,
bolted-in fittings at four of the six longeron forward ends so as to
provide direct load transfer. Fiberglass blocks and thermal blankets
reduce heat conduction to less than 0.2 W/°C. This type of attachment
fitting was used in the Burner IIA and P42-I units. The four structural
attach points feed acceleration loads directly into the base module
longerons.
The total weight of the AEM structural subsystem is 47.7 lb, consisting
of 27.2 lb of primary structure, 17.5 lb of secondary structure,
and 3 lb of mechanisms.
IMS STRUCTURAL SUBSYSTEM
The primary structural elements of the MMS ( 3 8 ' 3 9 ) for shuttle operation
are the module support structure and the transition adapter. The
power, attitude control and stabilization, and C&DH module skins are
secondary structural elements in that they support elements of the
spacecraft subsystems.
Module Support Structure
The module support structure provides structural continuity between
the transition adapter, subsystem modules, and propulsion module. Its
construction is basically a three-dimensional truss, with the six corners
as the primary load points. (Electrical connectors and other insignificant
loads may be hung on the struts themselves.) The Rockwell technical
proposal for fabrication shows the structural elements to be
primarily sheet, angles, and channels. The corner fittings appear to
be 60 deg V-shaped channels especially designed for triangular corners.
Transition Adapter
The transition adapter is the interface between the module support
structure and the mission adapter. During shuttle boost, it is also
the element that connects to the flight support system. The attachment