A Case Study in NASA-DoD - The Black Vault

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Table F-2
STPSS STRUCTURAL COMPONENT WEIGHT SUMMARY
Component
Structural Component
Weight (lb)
Core module ........................... 240
Spin-control-orientation module ....... 70
Three-axis-orientation module ......... 150
Precision three-axis module ........... 150
Solar array
Standard 50 W subpanel
(19" x 45") ....................... 3.0 ea.
"Picture frame" (boom, hinges,
etc.) ............................. 2.0-2.6 ea.
SOURCE: Ref. 1.
COMPARISON OF STRUCTURAL SUBSYSTEMS
The AEM is primarily aluminum sheet and stringer construction,
using standard Burner IIA extrusions for longerons. The conical shell
that interfaces between the spacecraft and the Scout F booster is probably
the most "exotic" structural element from a structures standpoint.
However, it too is formed from aluminum sheet, and fabrication appears
to be well within the state of the art and, in addition, will not be
used on STPSS missions.
The module support structure of the MS is a simple 3-D truss.
The subsystem modules utilize honeycomb panels that frame into aluminum
stock edges. The transition adapter is of more complex construction;
however, the fabrication procedures appear to be based on proven
techniques.
The basic structure of the STPSS appears to use more nonstandard
components, i.e., rings and diverging box beams. The structural weight
is also a higher percentage of the instrument payload weight than it is
in the AEM and M*S. Additionally, alignment may be a more critical
aspect of STPSS construction because loads have to be transferred between
the inner cylinders of the core module and orientation module
with minimal'edge moments. The additional complexity of the STPSS
structure will be reflected primarily as a fabrication cost, rather
than as one of development risk.