MICROGRAVITY SCIENCE EXPERIMENTS

Space Accelerations Measurement System

PIMS Project Manager: Richard DeLombard, Lewis Research Center, Cleveland, Ohio

Objective: When a space shuttle is in low Earth orbit, it is in a state of freefall around the Earth. This freefall results in a unique low-gravity environment called microgravity, in which researchers can conduct many types of investigations. The microgravity environment is characterized by a reduction in the effects of gravity compared to what we experience on Earth. Small vibrations and accelerations onboard the shuttle, however, can affect experiments the same way gravity does. Such disturbances can be too small for crewmembers to detect, but very sensitive measurement devices can detect them. Acceleration measurement devices assess the microgravity environment using specially designed sensors and allow scientists to characterize these disturbances and determine their influence on experiment results.

Description: On STS-95, a Space Accelerations Measurement System unit designed for suborbital rockets and free-flying satellites will be placed in the shuttle's cargo bay. The unit, called SAMS-FF, will serve two purposes: to record any disturbances in the microgravity environment for scientists with experiments on the mission and to support the Hubble Space Telescope Orbital System Test. The Hubble test is a trial of a new cryocooler for the Hubble Space Telescope. As the cryocooler cools the telescope's near infrared camera and multi-object spectrometer, SAMS-FF will collect vibratory disturbance data to determine whether operation of the cooler affects the ability to precisely point the telescope at a desired location.

After the mission, Principal Investigator Microgravity Services personnel will analyze and correlate the data with other ancillary data from the mission. Principal Investigator Microgravity Services will generate a report characterizing the microgravity environment for the Hubble test while the cryocooler was in operation and while it was turned off. This report will assist researchers in their assessment of the cryocooler's usefulness for the Hubble telescope and will give microgravity researchers important information they can use in the analysis of experiment results.