Space Station Crewmen Back Inside After Spacewalk
Space Station crewmen Jeff Williams and Thomas Reiter wrapped up a successful 5-hour, 54-minute spacewalk at 3:58 p.m. EDT Thursday. They installed and replaced equipment and set up scientific experiments outside the orbiting laboratory.
They had a third station crew member for the first time in more than three years. Expedition 13 Commander Pavel Vinogradov coached them through their prebreathe exercise program and helped them suit up for their outing.
The station crew was reduced to two members in May 2003 in the wake of the Columbia accident. Since then, spacewalkers have had to reconfigure station systems before donning their spacesuits without help.
Williams and Reiter were coached during their spacewalk tasks by Astronaut Steve Bowen. He will act as spacewalk intravehicular officer from the International Space Station Flight Control Room in Houston’s Mission Control Center.
The first and longest major task of the spacewalk was installation of the Floating Potential Measurement Unit (FPMU). That device is designed to measure the electrical potential of the station so ways can be verified or devised to minimize arcing hazards as the ISS grows.
Williams, designated lead spacewalker (EV1), wore the U.S. spacesuit with red stripes. Reiter, EV2, wore the all-white suit.
They spent about half an hour setting up equipment. They then moved with the FPMU to a camera mount near the upper outboard end of the S1 (starboard one) truss.
Next they moved back to the airlock. There they installed two Materials on International Space Station Experiment (MISSE) containers. MISSE 3 goes on one of the high-pressure tanks around the crew lock, while MISSE 4 is set up on Quest’s outboard end.
The experiment, housed in suitcase-like containers left open, looks at the long-time effects of space on a variety of materials. The idea is to identify optimal materials for use in future spacecraft.
Williams installed a controller for a thermal radiator rotary joint on the S1 truss. Meanwhile, Reiter replaced a computer on S1.
While Reiter finished that task, Williams began installation of a starboard jumper and spool positioning device (SPD) on S1. Reiter inspected a radiator beam valve module SPD site and installed one there, then moved on to install a port jumper and SPD.
The jumpers are designed to improve the flow of ammonia through the radiators once that coolant is installed.
Williams began setup for the final major task, test of an infrared camera designed to detect damage in a shuttle’s reinforced carbon carbon (RCC) thermal protection. The camera is designed to detect damage by variations in temperature between sound and damaged RCC test sections.
Williams did two get-ahead tasks. The first was installation of a light on the truss railway handcart. He then replaced a malfunctioning GPS antenna. After Reiter finished the infrared camera experiment with the RCC, he installed a vacuum system valve on the U.S. laboratory Destiny for future scientific experiments.
The crew still had spacewalk time remaining, so Mission Control came up with more extra tasks. They included moving two articulating portable foot restraints to prepare for an STS-115 spacewalk, photographing a scratch on the airlock hatch and retrieving a ball stack, which connects hardware to the station, for inspection from PMA-1.
The spacewalk ended with cleanup and airlock entry.
It was the third spacewalk for both Williams and Reiter. It was the 69th spacewalk to support station assembly and maintenance and the 22nd from the Quest airlock.
Their second job was to install two MISSE containers, or Materials on International Space Station Experiment. The suitcase-like containers are left open to evaluate the long-term effects of space exposure on a variety of materials. The idea is to identify optimal materials for use in future spacecraft. MISSE 3 went on one of the high-pressure tanks around the crew lock, while MISSE 4 was installed on Quest’s outboard end.
The two astronauts then went on to separate jobs. Williams installed a controller for a thermal radiator rotary joint on the S1 truss, while Reiter replaced a computer on the truss.
Williams then began installing a starboard jumper and spool positioning device (SPD) on the S1 truss. Reiter inspected a radiator beam valve module SPD site where one device was already installed and installed an additional one. He then moved on to install a SPD on a port cooling line jumper. The jumpers are designed to improve the flow of ammonia through the radiators once that coolant is installed.
Williams began setup for the final major scheduled task, a test of an infrared camera designed to detect damage in a shuttle’s reinforced carbon carbon (RCC) thermal protection. The camera highlights damage by showing variations in temperature between clean and damaged RCC test sections. Reiter operated the experiment while Williams went on to one of the additional tasks.
The first task was installation of a light to help future spacewalkers on the truss railway handcart. Williams then removed a malfunctioning GPS antenna. After Reiter finished the infrared camera experiment, he installed a vacuum system valve on the U.S. laboratory Destiny for future scientific experiments.
Mission control came up with additional tasks. Williams moved two articulating portable foot restraints to prepare for STS-115 spacewalks and then photographed a scratch on the airlock hatch. Reiter went to PMA1, a pressurized "corridor", to retrieve and inspect a ball stack, which holds hardware during spacewalks. The crew also had additional time throughout the spacewalk to photograph the worksites after their tasks were complete and then snap pictures of each other at the end. With no more quick tasks to add, the spacewalkers re-entered the airlock and closed the hatch early.
The next station status report will be issued on Friday, Aug. 11, or earlier if events warrant. For more about the crew’s activities and station sighting opportunities, visit:
