Setting up GPM on the High Capacity Centrifuge
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The GPM satellite, under construction, is fitted to the bed of the High Capacity Centrifuge for spin testing.
Testing GPM on the High Capacity Centrifuge
(ambient audio only)
GPM moves from the clean room to the test chamber on a dolly without wheels. Compressed air is pumped out under airpads that float the Spacecraft on a bed of air. The wind generated when the centrifuge moves at its maximum speed are more than 200 mph - that's tornado speed. But since they move with the centrifuge the satellites tested only feel 20 mph winds. Leaning outward at 45 degrees for one test orientation, GPM comes within 28 inches of the wall. When lifted onto the platform it cleared the ceiling by only five inches.
GPM's Solar Array Wings in Testing
(ambient audio only) This and other similar tests will verify the deployment function of the GPM Core Observatory solar arrays in ambient condition. Data such as deployment time, hinge forces, and system stiffness will be gathered and reviewed for requirement compliance. The qualification unit was assembled with flight and non-flight components. The flight components will be removed and integrated with the flight unit after qualification testing. GPM's two solar array wings that extend to the right (+Y) and left (-Y) of the spacecraft are currently undergoing assembly and testing at Goddard
Testing the GPM Solar Array
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The –Y wing undergoes modal testing, a type of vibrational testing.
The small squares are 59 accelerometers that measure the movement of the array.
Diagram of the GPM Solar Array Assembly
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A diagram of the GPM Core Observatory depicting various components of the Solar Array Assembly.
The solar arrays provide all the electrical energy for the satellite, and must survive flying in Earth's thin upper atmosphere at an altitude of 407 km (253 miles), where they will be subjected to small drag forces and exposure to corrosive atomic oxygen.