A Case Study in NASA-DoD - The Black Vault

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where SRU = Service Rendered Units, which may not exceed 100. It represents
a percentage of total launch cost. Length is in feet, weight in
pounds, inclination in degrees, and altitude in nautical miles. If
the SRU exceeds 100 ft it is assumed to be truncated at 100.
A formula proposed since the earlier phase consists of prorating
the dedicated shuttle cost on the basis of whichever of the load-factor
ratios below is larger:
1. payload length (in feet)
60
2.* payload weight (in pounds)
shuttle orbital capacity (in pounds) to the
desired inclination and altitude
In this study, we have assumed a direct relationship between load
factor, as determined above, and the cost factor for prorating the
dedicated shuttle cost. In some formulations of this tariff rate, the
load factor is multiplied by as much as a 1.4 cost factor; this has not
been used in this study. Because the launch cost is very sensitive to
payload length when using this NASA tariff, an attempt was made to
minimize launch cost by placing payloads laterally rather than longitudinally
in the shuttle bay whenever the payload length was less than
13 ft. Launch costs estimated using the above method are identified
as the modified NASA tariff.
The other cost-allocation schemes considered were: a full allocation
by weight, i.e.,
Private conversation with Mr. Edwin G. Dupnick at the Johnson
Space Center of NASA, October 1916.
Payload length is the sum of the lengths of the Space Test Program
payload, spacecraft, and solid kick stages.
For this study, nominal shuttle capacities of 65,000 lb for
ETR lainches and 39,000 lb for WTR launches have been used. A nominal
altitude of 150 n mi has been used. Solid rocket kick stages are used
to translate the spacecraft to higher orbits. Payload weight is the
um of the weights of the Space Test Program payload, spacecraft, and
kick stages.