ISS Expedition Two Science Operations Status Report 6 Apr 2001
Tests of the Middeck Active Control Experiment 2 begun during Expedition One
are continuing with the Expedition Two crew. These tests will continue
until the experiment returns to Earth along with the Expedition Two crew on
the 7A.1 Space Shuttle mission planned for July.
MACE studies the effects of vibrations on moving structures in space. Data
from the experiment can help engineers design strong, lightweight, low-cost
structures.
The MACE platform is 60 inches – or 152 centimeters – long, including four
struts and five nodes. Helms, who began MACE tests on Tuesday, used a
handheld control unit to send pre-programmed commands to the computer on the
MACE structure. These commands caused gimbals and reaction wheels attached
to one side of the structure to vibrate. A support module detected the
vibrations and attempted to damp them by activating gimbals and wheels on
the other side of the platform.
All data from the experiments are stored on removable hard drives for future
analysis by scientists on Earth. MACE involves science teams from the Air
Force Research Laboratory at Kirtland Air Force Base in New Mexico, and the
Massachusetts Institute of Technology at Cambridge.
Also Thursday, Flight Engineer Jim Voss completed maintenance on the Bonner
Ball Neutron Detector. Bonner Ball is one of three radiation-monitoring
experiments on board being used to characterize the station’s radiation
environment and the potential effects on humans. Voss replaced a hard drive
unit with a full memory with a new hard drive with fresh memory.
Editor’s Note: The Payload Operations Center at NASA’s Marshall Space Flight
Center in Huntsville, Ala., manages all science research experiments aboard
the International Space Station. The center is also home for coordination
of the mission-planning work of a variety of international sources, all
science payload deliveries and retrieval, and payload training and payload
safety programs for the Station crew and all ground personnel.
