Expedition 11 Commander Sergei Krikalev and Flight Engineer John Phillips are continuing routine maintenance and science experiments aboard the International Space Station (ISS), as they wrap up their first month in space.
The crew began the week observing the Russian holiday Victory Day. This year it marked the 60th anniversary of the end of fighting in the Soviet Union during World War II. The rest of the week kept Krikalev and Phillips busy with maintenance and research.
The crew used the treadmill for exercise this week as engineers closely monitored data from the sessions. The treadmill stopped working for a time last Friday, when a circuit breaker tripped inside the device. During today’s routine monthly inspection, Phillips reported a broken restraint cable on the treadmill’s gyroscope. The treadmill is specially outfitted to isolate the vibrations caused by exercise from the rest of the Station. It is also equipped with a gyroscope to maintain the system’s stability. Engineers will analyze photos of the restraint cable to determine whether it can cause problems with the treadmill’s operation. The crew will use other exercise equipment, including two stationary bikes, for the time being.
The Station’s atmosphere was pressurized again this week with oxygen from reserve tanks inside the Progress spacecraft docked to the ISS. The Station’s Elektron oxygen generation system, which can convert water into oxygen for the air onboard, is not operating. Russian engineers plan to send a new electronics box for the system on another Progress supply ship scheduled to arrive next month.
There are plentiful supplies of oxygen on board the Station available from multiple sources. Oxygen supplies already on the ISS, coupled with planned deliveries by cargo spacecraft, could sustain the crew for at least the rest of this year, without using the Elektron.
The remaining oxygen aboard the docked Progress will be used through next week. When depleted, Solid Fuel Oxygen Generation canisters may be used. There are 84 canisters on the ISS. Those canisters alone could supply the crew for at least 42 days, if necessary. A large quantity of oxygen, enough to supply the crew for almost 100 days, is stored in tanks on the Quest airlock aboard the Station.
The Progress docked to the ISS will undock at about 4:10 p.m. EDT, June 15. The new Progress, the eighteenth to go to the ISS, is scheduled to launch from the Baikonur Cosmodrome, Kazakhstan, at 7:09 p.m. EDT, June 16 and dock at 8:10 p.m. EDT, June 18.
The Station’s altitude was boosted on Wednesday to line up its orbit for the arrival of the new Progress. The Station’s orbit was raised by 1.5 miles at the perigee, the portion closest to Earth, to 226.1 by 214.2 statute miles. The new Progress will also deliver additional oxygen supplies. Another Progress craft is scheduled to arrive in August.
This week, both crew members worked on preparing excess equipment for return on the Space Shuttle Discovery in July on the Return to Flight mission, STS-114. They also performed routine maintenance on ventilation and life support systems in the Russian segment and verified a VHF radio communications link used during Shuttle rendezvous operations. Krikalev continued work throughout the Russian modules with audits of various supplies and equipment.
Phillips’ work focused on some of the laptop computers aboard. He refreshed a Portable Computer System (PCS) laptop by deleting and then reloading information on the hard drive, which recovered its corrupted hard drive to serve as a backup. The PCS laptops are used by the crew to monitor the Caution and Warning system, manage the Station operating modes and the Command and Control System. Two required PCS computers are functional onboard with three additional hard drives available as spares.
Phillips also worked with three Station Support Computers (SSCs) that were experiencing problems booting up. After the troubleshooting, two of the computers turned on, but the screens remained blank. They can be used for routing data in applications where a computer monitor is not necessary. The third laptop did not boot up and engineers are working on further troubleshooting procedures. There are enough operating computers onboard for the crew to access e-mail, perform word processing and view the daily schedule of activities.
Information about crew activities aboard the Space Station, future launch dates, and Station sighting opportunities, is available on the Internet at:
http://www.nasa.gov/station