Search This Blog

Saturday, March 15, 2008

Astronauts aboard the international space station overcame a worrisome power problem


Astronauts aboard the international space station overcame a worrisome power problem with their new, partially assembled robotic maintenance man late Friday, sending a wave or relief through his Canadian design team.

The fliers also floated into a newly installed Japanese module for the first time, finding the enclosure ready to occupy.

Dextre , a $209 million robot, and the 14-foot-long module, the station's first Japanese component, arrived aboard the shuttle Endeavour earlier this week. Both were transferred from the shuttle's cargo bay to the station late Thursday and early Friday. That's when it was discovered that Dextre could not receive electrical power for internal heaters that warm vital electronic circuitry.

Friday's accomplishments set the stage for a spacewalk late Saturday in which astronauts Rick Linnehan and Mike Foreman will resume Dextre's assembly by attaching two arms to his torso.

Dextre was developed to take on some of the space station maintenance work normally assigned to spacewalking astronauts.

"I guess I can say it's alive," Pierre Jean, the Canadian Space Agency's acting space station program manager, told a news briefing after the power problem was overcome. "A little bit of tension is relieved."

When fully assembled, Dextre will stand 12 feet tall with arms that stretch out 11 feet. The robot is so large, it must be stored outside the station, where the temperature swings are extreme.

"It was quite a relief, a real sense of success to see power applied," said Phil Engelhauf , NASA's chief flight director.

Efforts to begin the flow of space-station electricity to Dextre with a software patch early Friday failed to resolve the problem.

Working without a break, Canadian troubleshooters eventually tracked the source of the problem to a power cable within the pallet used to cradle Dextre's disassembled torso, arms and hands during Endeavour's launch.

The cable, engineers concluded, was not suited to handle both the flow of electricity and the exchange of data between the robot and a control panel inside the station.

As a workaround, Canadian engineers, decided to grapple the robot with the station's robot arm. The contact would establish a new path for electricity as well as the data exchange, they reasoned.

The strategy worked.

"Dextre has power," John Ira Petty, the commentator in NASA's Mission Control announced shortly after 9 p.m. CDT.

The pallet and the cable will return to Earth aboard Endeavour. Dextre will remain aboard the space station, plugged into one of several grapple fixtures like the mechanism on the end of the robot arm.

Also Friday night, three of the astronauts floated into the new module that will serve as an equipment locker for a larger Japanese lab called Kibo.

The Kibo lab is scheduled for launching aboard the shuttle Discovery in late May.

Station commander Peggy Whitson and Japanese astronaut Takao Doi led the way into the new module.

"This is a small step of one Japanese astronaut, but a giant entrance for Japan to a greater and newer space program," said Doi, who paraphrased the words spoken by American Neil Armstrong, when he became the first person to walk on the moon.

"We love our new room already," Whitson said. "We're very happy to have our new partner working with us more actively with the new module on board."

Japan becomes the last of the 15 nations involved in the American-led space station program to have a module added to the orbital outpost. When it arrives, the larger Japanese lab will house a variety of biology and physics experiments.

Doi, Whitson and Linnehan donned goggles and air masks as they floated in, garb to protect them from harmful dust and debris that may have been jarred loose during Endeavour's launch.

A third Kibo segment, an external experiment platform with a robot arm, is scheduled to arrive at the station in spring 2009.

Endeavour and a crew of seven astronauts lifted off early Tuesday on a 16 day mission, the longest shuttle assembly flight to the space station to date.

more......

Robot Dextre up and running
The International Space Station's new robot, Dextre, finally came to life Friday night after two days of troubleshooting by scientists.

The Canadian-built $210 million robot was delivered to the space station Thursday by the shuttle Endeavour. When the robot was removed from the shuttle, however, ground teams ran into problems routing power to the pallet on which the robot is being assembled. The teams tried troubleshooting the problem with a software patch early Friday morning, but were not successful.

On Friday night, ISS crew members used the station's robot arm -- Canadarm2 -- to successfully power up Dextre, NASA said Friday in a release.

Once it is fully operating, Dextre is expected to aid astronauts with spacewalks and repairs, USA Today said.

Friday, March 14, 2008

Astronauts forwarded to install lab section


Japan's elaborate research laboratory ready for installation on the International Space Station.Two U.S. astronauts floated out into open space on Thursday .

Four-time flier Richard Linnehan and his rookie partner Garrett Reisman left the station's airlock around 8:30 p.m. EDT (0030 GMT Friday) to begin the first of five spacewalks planned during shuttle Endeavour's 16-day mission.

The astronauts' first job is to remove protective thermal covers from a Japanese-built equipment storage chamber that flew into orbit in the shuttle's cargo bay.

The shuttle reached the station on Wednesday night.

The storage chamber, which contains computers and experiment racks, is the first part of Japan's space laboratory, known as Kibo, or "hope." The main part of the Kibo lab, which is about the size of a double-decker bus, is due to arrive at the space station in May.

An outdoor porch for exposing experiments to the vacuum of space will follow in 2009.

The spacewalkers also plan to disconnect a power cable to the module, clearing the way for Japanese astronaut Takao Doi, stationed inside Endeavour, to use the shuttle's robot arm to pluck the chamber from the cargo bay and twirl it into position on the station's Harmony connecting node.

Linnehan and Reisman will then turn their attention to a Canadian robot, named Dextre, that will add manual dexterity and 30 feet of reach to the station's crane.
NASA and the Canadian Space Agency were working on a software patch to bypass a problem that is preventing the $209 million robot from tapping into the station's electrical system.

"There's not a sense of great urgency," shuttle mission management team chairman LeRoy Cain told reporters. "We don't have our hair on fire."

Dextre can go at least five days before the cold of space becomes a problem, NASA's space station program manager Mike Suffredini told reporters at Houston's Johnson Space Center.

About half of the five spacewalks planned during Endeavour's 12-day stay at the station are dedicated to building Dextre, which has never been assembled on the ground.

With 11-foot-long arms and a mass of more than 1.5 tons, the robot would topple in Earth's gravity.

"It comes up in nine different pieces," Reisman said in a preflight interview. "We have to put him together."

NASA hopes to use the robot to help with detailed exterior station maintenance, cutting down the amount of time astronauts have to spend on risky spacewalks.

The space agency has two years to complete 10 remaining missions to the station before the aging shuttle fleet is retired. After that, the number of people who will have access to the station for part-time work will be greatly reduced.

A typical shuttle flight ferries seven visitors to the outpost. But NASA plans to rely on the Russian Soyuz capsule -- which carries three people -- to transport astronauts to the station after shuttle flights end in 2010.

The Endeavour crew won't have to spend any extra time surveying their ship for heat shield damage, managers decided on Thursday. After analyzing photographs taken by the space station crew as Endeavour approached for docking, engineers said the shuttle appeared in good shape for landing at the end of its planned 16-day mission.

NASA implemented a series of in-flight inspections after losing the shuttle Columbia and its crew in 2003 due to undetected heat shield damage.

Find here

Home II Large Hadron Cillider News