Status

September 29, 2010 – MAMS supported the Soyuz TMA-18 undocking from the International Space Station on September 24, 2010.  The ISS crew members were on the International Space Station for six months and returned on Soyuz; the crew included Tracy Caldwell, Mikhail Kornienko, and Alexander Skvortsov, all three returned safely on September 25, 2010.  The MAMS acceleration sensor measured the undocking event vibrations imparted to the ISS.

The MAMS is a complimentary acceleration measurement system to SAMS.  While the SAMS system measures acceleration disturbances from 0.01 to 400 Hz, the MAMS measures accelerations from DC to a maximum of 0.01 Hz.  MAMS provides this complimentary function by measuring accelerations caused by the aerodynamic drag of the ISS as it orbits the earth.  In addition, MAMS measures accelerations caused by small ISS attitude adjustments and ISS gravity gradient effects. These quasi-steady accelerations are confined in the frequency range below 1 Hz. MAMS consists of a low-frequency triaxial accelerometer, the Miniature Electro-Static Accelerometer (MESA), and associated computer, power, and signal processing subsystems contained within a Double Middeck Locker enclosure.

The MAMS MESA consists of a hollow, cylindrical flanged proofmass, two X-axis forcing electrodes, an outer cylindrical proofmass carrier with Y- and Z-axis electrodes, and control electronics enclosed in a protective case. Static electricity forces the sensor proofmass to remain centered between the electrodes. The "sensed" acceleration is proportional to the voltage needed to keep the sensor centered.  The MAMS MESA is mounted on a Bias Calibration Table Assembly (BCTA) with a dual-gimbal rotation system.  The BCTA and dual-gimbal systems allow the MAMS MESA to perform on-orbit bias calibrations.  With the MAMS electronic bias measured, the extremely small quasi-steady accelerations can be accurately sensed and transmitted to the ground to the Glenn Research Center Telescience Support Center for analysis and archive.

Related Web Sites

* Principal Investigator Microgravity Services (PIMS) Results Home Page
* NASA Glenn Research Center - SAMS
* NASA Glenn Research Center - MAMS