SCARI Development

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The SCARI instrument, detector, fore optics, and electronics make up the science payload. The other part to the rocket, called the bus, consists of the two boosters used to actually launch the rocket, the telemetry system, attitude control system, recovery system, and related electronics. Once the payload is fully assembled and tested at Boston University, it is brought down to the NASA Wallops Island Flight Facility for integration. Integration involved connecting the payload and bus to be sure the electronics and mechanical systems work together. The physical parameters of the rocket, such as mass, center of mass, moments of inertia, etc. are measured for launch.

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The ability of the rocket to survive launch is also tested. These tests include shake, shock, and bend. The shake and shock test are both done on a shake table, which shakes the entire rocket at the same forces the rocket will see during launch, which is about 13 G's of force --13 times the force of Earth's gravity. The above image shows the rocket getting ready for a shake test. Two things are being tested. The rocket must stay together during shake and launch, and all the optics, wires, electronics and bolts must stay intact and in place. A more difficult problem to overcome is the ability of the instrument's optics to maintain their alignment during launch. The rocket is shaken along the X, Y and Z axes. In the reference frame of the photograph, they are: up-down, side-to-side, and front-back.

The shock test is performed to check the rockets ability to survive the sudden, very violent points during launch, such as booster ignition. This used to be done by shooting the payload into a padded room, or dropping it. Now, it is performed on the shake table with a full G sine sweep, in which the rocket is shaken at increasing fast frequencies. This test induces up to 20 G's of force on the rocket.