So Long, SuitSat: Astronauts Launch Spacesuit in ISS Spacewalk
The ISS Expedition 12 crew toss SuitSat - an expired Orlan spacesuit equipped with ham radio equipment - into orbit. The ad hoc satellite will broadcast messages and an image to Earth for several days before burning up in the Earth's atmosphere.
Credit: NASA TV.

A doomed spacesuit is alone and tumbling through space after a Friday spacewalk by two astronauts outside the International Space Station (ISS).

ISS Expedition 12 commander Bill McArthur and flight engineer Valery Tokarev launched the ham radio-equipped spacesuit - an expired Orlan dubbed "SuitSat" that researchers had hoped would broadcast for days - at the start of their spacewalk 220 miles (354 kilometers) above Earth.

"Goodbye, Mr. Smith," said Tokarev, a cosmonaut with Russia's Federal Space Agency, as he shoved the spacesuit away from the ISS.

Video cameras mounted to the exterior of the ISS watched as the tumbling SuitSat drifted away.

Less than one hour later, flight controllers reported that SuitSat was performing as expected - though admittedly with a weaker than expected signal - transmitting greetings to the Earth in five different languages and other data down to Earth. [Click here for more information on the SuitSat experiment.]

"Japan has been listening," veteran NASA astronaut Michael Foale, serving as spacecraft commander, told the Expedition 12 crew. Coincidentally, Foale was the last astronaut to wear the Orlan spacesuit - during a spacewalk in February 2004 - now orbiting the Earth, NASA officials said.

"Really, that's outstanding," said McArthur, who is serving as NASA's science officer during Expedition 12.

But after only two orbits, or about three hours, SuitSat went silent. [Note: Later updates found that the spacesuit was indeed still broadcasting a signal, albeit very weak.]

"Apparently, the batteries on the spacesuit have either frozen or died," NASA commentator Rob Navias said. "SuitSat is no longer being heard by ham radio operators around the world."

SuitSat will eventually burn up in the Earth's atmosphere in a few weeks' time, NASA officials said.

The Expedition 12 crew tossed SuitSat behind the ISS, in the opposite direction of the station's relative motion, about 18 minutes after exiting the Pirs docking compartment clad in their own, red-striped Russian-built Orlan spacesuits at 5:44 p.m. EST (2244 GMT). McArthur and Tokarev spent a total of five hours and 43 minutes walking in space, NASA officials said.

Cable woes

Amid other ISS science and maintenance tasks, McArthur and Tokarev were also tapped to safeguard a vital cable against an automated guillotine-like system attached to the station's Mobile Transporter.

The Mobile Transporter moves much like a railcar to transport the outpost's robotic arm, astronauts or massive ISS components - such as solar arrays - across the space station. Two cables, one primary and a backup, transfer power, data and video between the transporter and the ISS.

But in December, a spring-loaded cutter system designed to fire in the event of a snag inexplicably cut a trailing umbilical cable, leaving the Mobile Transporter with only one working cable.

McArthur and Tokarev attempted to drive a safing bolt, which would block the cutter system from firing into the operable cable system, but were unable to install the bolt completely using power screwdriver-like pistol grip tool.

Instead, the astronauts removed the cable from the cutter system entirely. But while that guarantees the vital cable will not be accidentally cut, the solution also rendered the Mobile Transporter immobile until the cutter system can be replaced or fixed, NASA officials said, adding that it could a problem for astronauts set to repair the severed cable during NASA's next shuttle flight - STS-121 aboard the Discovery orbiter - to launch later this year.

"It's disappointing that it didn't go exactly like we wanted, but that's life in the big city," McArthur said after the activity.

Grapplers, biology and photography in space

SuitSat and the bolt safing work aside, the rest of the Expedition 12 crew's spacewalk went swimmingly.

McArthur and Tokarev moved a grapple fixture used to attach Russian-built Strela cargo booms to the ISS from its perch along the station's Zarya control module to a new berth at alongside the Pressurized Mating Adapter-3 (PMA-3), where NASA space shuttles dock during station-bound flights. STS-121 spacewalkers plan to use the Strela crane during their upcoming mission.

The Expedition 12 crew also retrieved a canister full of microorganisms, part of the Russian experiment Biorisk, and will return it to Earth for researchers studying the space environment's effect on living creatures.

For their final task, McArthur and Tokarev hauled themselves hand-over-hand to the aft end of the station's Zvezda service module, where they took detailed photographs of peeling paint and soot-covered areas discolored by residue from the module's thruster firings over the years. Engineers on the ground will go over the images to study the state of the module.

"Thank you Bill, good job," said Tokarev, who served as lead spacewalker during the extravehicular activity, after the astronauts had climbed back inside the Pirs docking compartment.

Friday's spacewalk marked the second career spacewalk for Tokarev and the fourth for McArthur following a Nov. 7, 2005 excursion. Together, the two astronauts have spent 11 hours and five minutes walking space during their mission. While that's a total for Tokarev, it brings McArthur up to 24 hours and 21 minutes of orbital work sans spacecraft.

To date, astronauts have performed 64 spacewalks to assemble and maintain the ISS, 36 of which were launched from the station itself with14 of those beginning at the Pirs hatch. Humans have spent 384 hours and 23 minutes putting together and repairing each piece of the ISS since its first component launch in 1998, NASA officials said.

McArthur and Tokarev have lived aboard the ISS since October 2005, and are slated to return to Earth in early April.

"What a beautiful spacecraft this is," McArthur said of the station during Friday's spacewalk. "It was an adventure."