A Case Study in NASA-DoD - The Black Vault

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The approach used by the Space Test Program Office in the past to
satisfy the heterogeneous array of payload requirements on the spacecraft
has consisted of minimizing the interaction of one experiment with
another. However, with the recent availability of a new fault-tolerant,
general-purpose spacecraft computer, it is possible to consider coupling
two or more payloads. Information may be extracted from individual payloads
and computationally reduced on board, thereby lowering the bandwidth
(27)
of information transmitted to the ground.
The Space Test Program Office became interested in the standard
spacecraft concept because of the possibility of combining this capability
with the possibility of further reducing the spacecraft cost by
procuring a fairly large number of spacecraft at a given time.
This
concept was especially interesting with the advent of the space shuttle,
where the match between launch vehicle and mission is not as
critical as it has been when expendable boosters were used as launchers.
As a consequence, the Space Test Program Office sponsored the design of
a modularized standard spacecraft (STPSS) that has the capability of
meeting all of its payload requirements, while also conforming to their
low-cost design philosophy.
Objectives and Guidelines
The two objectives of this case study are to develop internally
consistent cost estimates for the AEM, L-AEM, STPSS, and MMS spacecraft
and, using these estimates, to determine the variation in program cost
for a variety of spacecraft procurement options capable of performing
the Space Test Program missions during 1980-1990. The emphasis is on
relative, not absolute, accuracy in the estimates developed. The conclusions
that are drawn concerning the various procurement options,
although discussed in terms of total program costs, are dependent upon
the relative costs of the various spacecraft (see Sec. IV). They are
not affected if the magnitude of the total program costs is underestimated
or overestimated.
The study guidelines are summarized below:
Before the space shuttle, the Space Test Program had the option of
selecting the launch vehicle to fit the particular mission requirements,
e.g., in 1976, both the Titan III and Scout launch vehicles were used.