Despite previous excursions outside their home, the crew of the International Space Station (ISS) is gearing up for their mission's first officially planned spacewalk, though it will be the third time they leave the station.
ISS Expedition 9 commander Gennady Padalka and NASA ISS science officer Michael Fincke will again don their Russian Orlan spacesuits, this time to prepare the space station to receive a European cargo pod and update science equipment attached to vehicle's exterior.
Hatch opening for the spacewalk is currently scheduled for 3:10 a.m. EDT (0710 GMT) on Tuesday, Aug. 3, when the astronauts will step outside the station's Pirs docking compartment.
Padalka and Fincke arrived at the ISS on April 21 and have already tucked two unplanned spacewalks under their collective belts. The first, an aborted repair job, lasted only 14 minutes. But the second outing ended in a successful five-hour spacewalk.
Unlike both of those previous extravehicular activities (EVAs), which were planned quickly while Padalka and Fincke were already in orbit, ground and station crews have long-trained for the upcoming spacewalk.
"This EVA was part of the original Expedition 9 plan," said Matt Abbot, NASA's Expedition 9 lead flight director, during a press briefing on the spacewalk at NASA's Johnson Space Center (JSC) today. "The crew and vehicle are doing great."
A crucial spacewalk
The primary goal of Tuesday's spacewalk is the installation of laser reflectors and an antenna to on the aft end of the Russian Zvezda service module. The crew will also disconnect a cable from a failed television camera on Zvezda's docking port as well.
The upgrades are a vital part of the docking system for the Automated Transfer Vehicle (ATV) developed by the European Space Agency (ESA). The robotic supply ship can carry three times as much cargo as a Russian Progress vehicle and is due to make its first resupply run to the ISS in 2005.
"It will significantly enhance our ability to deliver dry cargo and water and supplies to the station," said Mark Geyer, NASA's ISS manager for integration and operations at JSC, of the ATV.
Padalka and Fincke will also retrieve and replace a variety of space experiments attached to the exterior of the Zvezda module, including a series of instruments that expose materials to space and Kromka devices that measure thruster contamination to the station surface.
Janice Voss, Expedition 9 increment scientist, said that the current space station crew has completed 25 percent more science than mission planners expected for this point in their expedition, largely due to the efforts of NASA astronaut Michael Fincke.
"Mike Fincke has chosen to do science on his off-time...mostly on Saturdays, but also during evening time," Voss said. "It's been a huge effort on Mike's part."
An eventful future
In addition to the upcoming spacewalk, the Expedition 9 crew is expecting a series of mission milestones in the next two months.
"We're really ready to move into the next phase of this increment," Geyer said of Expedition 9 flight and ground teams during the briefing.
On Friday, Padalka and Fincke will cast off their Progress 14 cargo ship, laden with trash, to make room for new shipment of supplies and equipment next month. The new supply ship, Progress 15, is scheduled to launch from Baikonur Cosmodrome in Kazakhstan on Aug. 11 and arrive at the ISS on Aug. 14. A final Expedition 9 spacewalk is also set for mid-September.
Meanwhile, the next crew bound for the ISS, Expedition 10's Leroy Chiao and Salizhan Sharipov, are slated for launch on Oct. 9 to relieve Expedition 9 and start their own six-month stay in space.