This past June marked an exciting milestone for Voyager Space—the 33rd anniversary of the Space Acceleration Measurement System (SAMS)! First launched on the Space Shuttle in 1991 by the Voyager team (legacy ZIN Technologies) in collaboration with NASA’s Glenn Research Center, SAMS today measures and tracks tiny disturbances that mimic the effects of gravity aboard the International Space Station (ISS). The system includes two accelerometer subsystems: SAMS-II and the Microgravity Acceleration Measurement System (MAMS).
SAMS is noteworthy not only because it has characterized every NASA crewed spacecraft over the past three decades—including the ISS, Space Shuttle, and the Russian MIR—but also because it documents disturbances in an on-orbit microgravity environment. These disturbances, caused by crew motions, vehicle systems, attitude changes, and more, can impact sensitive onboard science experiments.
Since its inception, SAMS has collected vast amounts of data, enhancing the quality of future space experiments. Today, SAMS has 10 of the 12 sensors (combination of SE and TSH-ES) onboard ISS deployed and operating. On average seven sensors are collecting data continuously, 24 hours a day, seven days a week. When three main ISS facilities (Fluids Integrated Rack, Combustion Integrated Rack, and Microgravity Science Glovebox) are operating, there can be up to 10 deployed sensors operational throughout all three main labs of the space station. As of this July, SAMS on ISS has collected over 785,000 sensor hours, which totals to more than a trillion acceleration measurements made aboard the ISS by SAMS since 2001.
SAMS-II, the hardware currently used on the ISS, measures accelerations caused by vehicle, crew, and equipment disturbances in the frequency range of 0.01 to 300 Hz. MAMS, on the other hand, records accelerations caused by aerodynamic drag as the ISS moves through space and small accelerations from vehicle rotations and water venting in frequencies below 1 Hz.
Data from SAMS-II is utilized by the Principal Investigator Microgravity Services (PIMS) and transmitted to the Control Unit (CU), which then sends it to the Glenn Research Center for processing and display on the PIMS Space Station website. SAMS-II is designed to record accelerations throughout the Space Station’s lifetime. MAMS supports the ISS Loads and Dynamics Group with ISS re-boost maneuvers every two to three months to prevent the station from deorbiting.
SAMS units have played crucial roles in numerous extraordinary missions over the years and greatly informs how we look at developing our commercial space station, Starlab. Cheers to 33 years and counting!