3149. Weight Verification of a Pressure Stabilized Vehicle

Paper

Abstract

Verify the predicted weight of a launch vehicle before flight. Weigh the vehicle to reduce the uncertainty associated with itsweight, ensure the performance requirements acquiesce, and thereby increase the probability of mission success.
Obtain a gross weight of the vehicle using the appropriate calibrated weighing equipment. Establish the as-weighed configuration. Rectify the actual weight to the flight configuration. Consider shortages and overages, such as handling fixtures and non-flight hardware that must be removed before flight. Determine the buoyancy effect of the air displaced by the vehicle and its handling fixtures. Take into account the composition and pressure of the gas in the tank. Base the ambient air density on temperature, relative humidity, and barometric pressure. Document all results.
The fundamental systems engineering process described in this paper is used on the highly successful Atlas launch vehicle program. This paper provides a method to determine an actual weight adjustment that is applicable to the predicted launch vehicle mass properties. The weight of every Centaur upper stage is verified in this manner.