The 60-foot-long arm was maneuvered by ground control Friday to move in, latch onto a fixture on the exterior of the Station, then release and move back out. The tests were the second and most complex remote control operations of the arm performed by the ground. A first set of tests, completed earlier this year, involved only basic movements. Completion of these two phases of commissioning will qualify the ground control capability to be considered for use during future Station operations if needed.
During the tests, the arm was controlled by the robotics officer, or ROBO, in the Space Station Flight Control Room of Mission Control. Aboard the Station, Flight Engineer and NASA Science Officer John Phillips monitored the activity. Normally, the arm is controlled by the Station crew using a robotics workstation in the complex's Destiny Laboratory.
Other activities this week for the Expedition 11 crew included some brief additional troubleshooting of the Elektron oxygen generation unit on the Station. At the direction of Russian flight controllers, Commander Sergei Krikalev tightened a valve in the unit, attempted to pressurize the system and checked for leakage. Similar attempts may continue in the future using other Elektron components and additional monitoring. The Elektron, a system that can derive oxygen from water for use in the Station atmosphere, remains inoperable.
The crew continues to replenish oxygen aboard the Station each day using two solid fuel oxygen generation canisters, canisters that contain chemicals that release oxygen when heated. Plentiful supplies of oxygen remain aboard the Station, and more is set to arrive on the next supply ship later this month. With reserves onboard the complex now plus those planned to arrive on future supply ships, oxygen is available to provide for the crew until at least January 2006 even without use of the Elektron. In addition, new Elektron components and spares also are planned to be launched aboard future supply ships later this year.
Phillips worked this week with an experiment that studies the forces involved as fluids of different thicknesses are mixed. The Miscible Fluids in Microgravity (MFMG) investigation may provide insight into how fluids dissolve, and, in particular, the role played by surface tension in that process. On Earth, gravity makes it difficult to study the role of surface tension during mixture. Information from the experiment may be useful in many processes on Earth and in space science experiments that deal with mixing fluids, among them are investigations that grow protein crystals of use in medical research.
Next week, the crew will begin packing trash and unneeded equipment in the Progress supply ship currently docked to the Station. The current Progress will be undocked from the complex on June 15. The next supply ship, ISS Progress 18, will launch on June 16 and dock to the Station June 18.