Expedition 8 Commander Michael Foale and Flight Engineer Alexander Kaleri spent two days last week replacing a liquids unit and a water flow system of the Russian Elektron, in the Zvezda Service Module. The Elektron separates water into oxygen and hydrogen. The oxygen is used in the Station's atmosphere while the hydrogen is vented overboard.
The Elektron had shut down repeatedly after only brief periods of operation during the past several weeks. In the meantime, the crew used oxygen and air from the Progress cargo vehicle docked at the Station to replenish the atmosphere, as well as Solid Fuel Oxygen Generation (SFOG) canisters. Each canister can supply the oxygen needs of one crewmember for one day.
A total of 13 SFOGs were used during the week before the Elektron was repaired and activated. More than 100 SFOGs remain on board, and two high-pressure tanks on the Station's Quest airlock contain a supply of oxygen that could last several months if needed.
With the Elektron running smoothly, Foale and Kaleri devoted much of the week to science activities.
Kaleri tended the Rasteniya experiment, a greenhouse containing peas, designed to see how plants grow in a microgravity environment. Kaleri also did a test of the Russian TORU manual docking system, using the ISS Progress 13 vehicle docked to Zvezda. That Progress is to be undocked and burn up in the Earth's atmosphere in mid-May, the day before a new Progress arrives with about 21/2 tons of equipment, supplies, water and fuel.
Foale also worked with the Miscible Fluids in Microgravity (MFMG) experiment. It involves injecting honey into a water container to see how the two combine in weightlessness. He also worked with the Pore Formation and Mobility Investigation, melting a transparent material in the Microgravity Science Glovebox to observe the formation and interaction of bubbles in the material. The experiment could help in prevention of bubble formation during such processes, perhaps resulting in stronger materials.
On Monday and Tuesday, both crewmembers wore acoustic dosimeters for about eight hours as part of regularly scheduled tests of the Station's noise levels. For the last half of both days, they removed the dosimeters and set them up in stationary locations. On Tuesday, both crewmembers talked with students at Mill Middle School in Williamsville, N.Y.
Today Foale and Kaleri did a periodic, detailed inspection of one of two U.S. spacesuits on the Station. The other is not scheduled for inspection for several months.