Microgravity Environment Measured During Shuttle-Mir Science Program

One of the first experiments of the Shuttle-Mir Science Program was the Space Acceleration Measurement System (SAMS). The SAMS project at the NASA Lewis Research Center supports microgravity science experiments by measuring microgravity accelerations during on-orbit experiments. The Principal Investigator Microgravity Services (PIMS) project at Lewis supports principal investigators of microgravity experiments as they evaluate the effects of these varying acceleration levels on their experiments.

In August 1994, three U.S. experiments were launched in a Progress vehicle to the Mir station: SAMS, the Tissue Equivalent Proportional Counter, and the Mir Interface to Payload Support. The SAMS experiment was installed in the Kristall module of the Mir complex (see figure), where early U.S. experiments will be operated.

Mir space station.

SAMS measures microgravity accelerations during the experiments, characterizing the microgravity environment to which they are exposed. During initial operations, data were collected in seven different time periods to survey the locations of the Protein Crystal Growth Experiment and the Russian Gallar Furnace in the Kristall module. A total of 53 hr and 14 min of microgravity data were collected on two data disks. These were returned to Earth in a Soyuz vehicle in November 1994. Personnel of the Lewis SAMS project quickly processed the data, and the Principal Investigator Microgravity Services project personnel prepared a quick analysis. Results were published in a NASA Technical Memorandum (ref. 1).

The Mir acceleration data were examined by the PIMS team to establish the principal characteristics in the Mir microgravity environment. Having analyzed similar activity periods on the Mir space station and NASA's space shuttles, we can deduce that the microgravity environment on these vehicles is similar.

The SAMS Mir data files can be accessed from a file server at Lewis, along with data from other SAMS missions. A request for access instructions may be sent in an electronic mail message to pims@grc.nasa.gov.

The SAMS unit also will support experiments onboard the Mir space station when more U.S. and Russian experiments are operated in the Priroda module to be installed in 1996. We estimate that an equivalent to 300 days of microgravity data are going to be collected throughout the entire Shuttle-Mir Program and NASA-Mir Program.

Reference

1. DeLombard, R.; and Rogers, M.J.B.: Quick Look Report of Acceleration Measurements on Mir Space Station During Mir-16. NASA TM-106835, 1995.