Mass properties testing is performed to determine characteristics of the radioisotope power systems (RPS) that are important to the flight stability of the spacecraft. Technicians take measurements to very accurately determine the weight of the RPS, its center of gravity (CG), and its moments of inertia (MOI).
Mass properties tooling in SSPSF include:
A Mettler Toledo scale model KCC150 with a 150 Kg (330 lb) capacity and electronic display model ID1 Plus. It has an uncertainty of less than 0.05 lbs. over the 330-lb range.
The mass properties instrument is a Space Electronics, Inc. Model KSR1320-1500. It has the capability to measure the center of gravity of an object to within a sphere of 10 mm and moment of inertia to +/- 0.1 percent.
The mass properties information is obtained by SSPSF operators and supplied to parent spacecraft program. This information is needed to calculate an overall vehicle weight, center of gravity, and moment of inertia.
The mass properties testing is part of several steps in ensuring proper assembly and finished product quality of the RPS.
Equipment capabilities include:
CG to sphere of 10 mm
MOI +/- 0.1%