A Case Study in NASA-DoD - The Black Vault

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5. Using off-the-shelf, space-qualified hardware whenever
possible.
6. Staffing a project with a small, responsible team (about
ten individuals per major project).
The type and number of payloads flown on a Space Test Program mission
vary widely. For example, one upcoming mission consists of experimental
payloads from the Army, Navy, Air Force, and ARPA. The mission includes
seven payloads having a total weight of 700 lb. Three of the payloads
require a sun-pointing orientation, while the remainder require earth
scanning. The spacecraft therefore must be three-axis stabilized
with the capability of scanning the earth. Another mission includes
twelve small payloads to investigate the same phenomenon--spacecraft
charging at altitude--having a total weight of 200 lb.
As will be discussed later in this section, a Space Test Program
mission model consisting of descriptions of a number of experiments proposed
by various agencies and departments was used in the evaluation of the standard
spacecraft acquisition decision. These payloads can be arrayed in a
variety of dimensions, as discussed later, but for the sake of providing
some understanding of the nature of the problem that these payloads present
to the Space Test Program Office, the following ranges of requirements are
included in the 1980-1990 Space Test Program mission model: (2 6 )
Operating
Parameters
Typical Range of Requirements
Weight
Electric power
Data rate
Stabilization
Orientation
Pointing accuracy
Apogee altitude
Perigee altitude
Inclination
1 to 525 lb
0.001 to 100 W
0.001 to 64 kbps
Three-axis or spinning
Sun-pointing or earth-pointing
+ 0.5 to + 15 deg
100 to 20,000 n mi
100 to 20,000 n mi
Equatorial to polar