Spacewalkers run into bolt problem; SuitSat falls silent
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 3, 2006
Space station commander Bill McArthur and flight engineer Valery Tokarev ended a five-hour 43-minute spacewalk tonight, closing the hatch of the Russian Pirs airlock module at 11:27 p.m. EST. The spacewalkers accomplished all of their primary objectives, but problems "safing" a protective cable cutter on a key station component will complicate already planned repair work by the crew of the next space shuttle mission.
And in a disappointment to amateur radio enthusiasts, an old Russian spacesuit that was dumped overboard as part of an amateur radio project stopped transmitting shortly after its release. Russian project managers had hoped a battery powered radio inside the Orlan spacesuit would continue operating for several days.
"Reports are now coming in from the amateur radio operators affiliated with the international space station program that the SuitSat that was deployed 18 minutes into tonight's spacewalk may have ceased transmitting, perhaps because its batteries had become too cold," said NASA commentator Rob Navias.
"No more transmissions are being received by ham radio operators anywhere around the globe. ... SuitSat was putting out faint signals for the first two orbits following its deployment by Tokarev. But now apparently no more transmissions are being heard and although continued efforts are being made to try to raise signals from SuitSat, it may have ceased operating very shortly after its deployment."
Today's spacewalk began at 5:44 p.m. and ended at 11:27 p.m. for a duration of five hours and 43 minutes. It was the 64th spacewalk devoted to space station assembly and maintenance since construction began in late 1998, pushing total EVA time to 384 hours and 23 minutes. This was the second spacewalk by McArthur and Tokarev, who have now logged 11 hours and five minutes of EVA time.
The cable cutter is one of two on a mobile transporter used to move the station's big robot arm to different work sites. The transporter is operated through two redundant power-and-data cables and the cutters are in place to make sure a tangled or jammed cable cannot stop the platform between work sites.
But one of the cable cutters fired last December for no apparent reason, severing one of the two power-data-video cables needed to operate the platform. NASA astronauts plan to replace the severed cable during the next shuttle flight and until then, flight controllers wanted to make sure that whatever caused the suspect cable cutter to fire could not happen again.
The issue is critical because the station's robot arm is required to install extensions to the lab's solar array truss during upcoming assembly flights. NASA flight rules prohibit major movements of the arm transporter until full redundancy is available.
To ensure the remaining operational cutter doesn't sever the remaining cable even if it inadvertently fired, McArthur and Tokarev had hoped to drive a safing bolt into place that would physically prevent the blade from engaging the cable.
But the spacewalkers were unable to drive the bolt into position. After a bit of debate on the ground, flight controllers told McArthur and Tokarev to simply remove the good cable from the operational cutter mechanism and to use cable ties to secure it to a nearby handrail.
While the work-around safed the system as required, it also completely disabled the mobile transporter. Engineers now will have to develop a repair strategy, complicating the work already planned for the next shuttle crew. While flight rules require two operational cables before the mobile platform can make major moves to support station assembly work, the shuttle crew had planned to move it from one work site to another to provide better access for replacing the severed cable and its cutting mechanism.
Engineers now will have to develop a strategy for restoring the intact cable to use along with replacing the other cable and its support equipment.
"We did the best that we could," McArthur said to Tokarev.
Astronaut Mike Foale in mission control at the Johnson Space Center congratulated the spacewalkers on "a super job" and told them not to be disappointed. Surprised, yes, but not disappointed.
"It is disappointing it didn't go exactly the way we want, but that's just life in the big city," McArthur said. "Any reports on SuitSat?"
"We're hearing that Japan has been hearing (SuitSat)," Foale replied.
"Really? Well, that's just outstanding!"
However, mission control announced a few hours later that SuitSat's signals were no longer being heard.
The old Russian Orlan spacesuit was jettisoned by the spacewalkers at 6:02 p.m. Video from the space station showed the suit slowly tumbling away in the deep black of space in a scene reminiscent of fictional astronaut Frank Poole's computer-orchestrated death in "2001: A Space Odyssey."
"Goodbye, Mr. Smith," one of the spacewalkers said as the spacesuit tumbled away over the south Pacific Ocean.
The spacesuit was packed with amateur radio equipment designed to transmit pre-recorded messages, telemetry and digital images to students and radio enthusiasts during its brief orbital life.
After launching SuitSat, McArthur and Tokarev made their way to the top of the Russian Zarya module's docking adapter and moved over to the U.S. side of the station. They removed a Russian grapple fixture that had been stored on the side of a U.S. component and repositioned it on Zarya's docking adapter. The grapple fixture will be used during a future mission to anchor a Russian space crane. The crane, in turn, will be used to move Russian micrometeoroid panels.
With the grapple fixture in place, the spacewalkers moved up to the station's solar array truss for the work to install the safing bolt on the mobile transporter.
Later, they made their way back to the Pirs airlock module and retrieved a Russian space exposure experiment called Biorisk. The final task of the spacewalk was floating to the aft end of the Zvezda command module for a detailed photo survey to document the condition of various external systems.