Spaceflight Now: Space Station/STS-98

U.S., Russia approve cargo ship redocking to station
BY WILLIAM HARWOOD
SPACEFLIGHT NOW

Posted: December 19, 2000

  Station
The Progress views the space station while trying to align itself under automatic control during a failed docking attempt last month. Photo: NASA TV/Spaceflight Now
 
NASA's mission management team today formally approved a Russian proposal to redock the Progress M1-4 cargo vehicle to the international space station on Dec. 26.

The primary goal of the maneuver is to test a software patch designed to correct an automatic guidance system problem that forced cosmonaut Yuri Gidzenko to take over manual control during the craft's initial docking Nov. 18.

"We had some problems with the automated docking when Progress came the first time," station flight engineer Sergei Krikalev told a reporter today. "We were able to dock it manually and Yuri did a good job flying it in manual mode.

"People on the ground think they have found the problem, they have fixed it and they want to be sure this problem is fixed and they want to make another attempt with this Progress to be sure the software is correct for the next flight."

The Progress M1-4 spacecraft was undocked from the Zarya module's Earth-facing port Dec. 1 to make room for the shuttle Endeavour, which docked to a nearby port on the U.S. Unity module the next day.

The Progress, meanwhile, was "parked" several hundred miles ahead of the station in the same orbit while U.S. and Russian ground controllers assessed redocking options.

The Russians want to test the guidance system software patch and to give the crew additional trash stowage volume.

NASA managers initially opposed a redocking because final approach would have to be carried out manually by Gidzenko using the station's TORU system. The TORU system is made up of a television monitor and a joystick controller that allow an approaching Progress to be remotely piloted from inside the Zvezda command module.

The presumably repaired KURS automatic guidance system can still maneuver the craft to a point about 600 feet from the station. But a fully automated redocking is not possible because an antenna used for final approach was retracted during the initial docking and it cannot be re-extended.

But NASA's mission management team today approved a manual redocking based on assurances from the Russians that final approach could be aborted in the event of a TORU malfunction.

"The system has a lot of built-in ways to protect us from something bad happening," commander William Shepherd said today during an interview. "Yuri's not about to do anything imprudent. He did a good job of docking before. As long as we have reasonable control and a good picture, I think we'll be successful. I'm not worried about it."

ISS
The 97-ton international space station with its solar wings spread as seen by Endeavour during undocking. Photo: NASA
 
The approved plan calls for the KURS automatic guidance system to move the craft to its station-keeping point 600 feet from the station early Dec. 26.

Gidzenko then will take over manual control using the TORU system, remotely piloting the craft to a docking with the Zarya module's downward-facing nadir port around 6 a.m. EST (1100 GMT). The docking will be carried live on NASA television.

Looking ahead to Christmas, Shepherd said the station crew plans to spend a bit of time enjoying the view from 230 miles up and to share a turkey dinner. They also will open presents from friends and family members that were ferried up aboard the shuttle Endeavour earlier this month.

Shepherd said the crew has resisted the temptation to open any presents early, but he admitted to shaking a few to get a feel for what might be inside.

Krikalev, a veteran of the Mir space station, said the now-abandoned Russian outpost was equipped with a small Christmas tree that cosmonauts would decorate for the holidays.

No such tree is aboard the international space station. Yet.

"Unfortunately, this is the first expedition and next year, we'll have a Christmas tree here," he said.

Asked about the health of the station's Vozdukh carbon dioxide removal system, Shepherd said he is confident his crew could make repairs even if the system fails again.

Last week, station flight director Jeff Hanley said the crew was one failure away from a potential evacuation after two earlier failures of the Vozdukh's microcompressor fan assembly.

"We're a pretty resourceful bunch up here," Shepherd said. "I'm pretty convinced if we had more serious failures, we could probably go fix the hardware on board.

"We're pretty good tearing into things and figuring out what we need up here. The ground sometimes is kind of reluctant to let us do that. But I think it's kind of the way of the future.

"People on spacecraft like this a long way from home have got to be more and more able to fix things themselves," Shepherd said. "And that's kind of the mode we're pointing at right now."

Finally, Shepherd was asked how the crew felt about recent delays in the shuttle flight scheduled to return them to Earth. That flight, originally scheduled for launch Feb. 15, has slipped to around March 1 because of technical problems.

"I think all of us took off on this mission with the thinking it was going to be over when it was over and as long as we get home sometime in the spring, we'll be happy with that," Shepherd said.

"If you look back at the people who did the initial exploration hundreds of years ago, some of those people lived on ships for years traveling the globe and didn't even get off. So I think the comparison, having to be on space station for an extra couple of weeks, is a pretty minor thing."

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