Elusive ‘handshake’ achieved; Hadfield bound for Earth: Endeavour mission

Original publication date: April 30, 2001

ST-HUBERT, Que. – Canadian astronaut Colonel Chris Hadfield is on his way back to Earth today, after a "Canadian handshake" between two generations of Canadian-built robotic arms was finally completed three days behind schedule.

The shuttle Endeavour undocked from the International Space Station yesterday afternoon, ending a long, often frustrating mission in which Canada played a central role.

Col. Hadfield became the first Canadian to walk in space, installing a $1.4-billion robotic arm, which is this country’s main contribution to the station. However, faulty U.S.-built computers delayed the final testing of the new Canadarm2.

"There’s a lot of really really happy people down here on the ground," Phil Engelauf, NASA’s lead flight director, said after the shuttle undocked from the station somewhere over the South Pacific. "We’ll have a couple of cold ones when you get back."

The Canadarm2 finished its first real job on Saturday, handing off a 1.3-tonne cargo pallet to its older cousin the Canadarm aboard the shuttle Endeavour.

The work was delayed not by problems with the Canadarm2, built in Brampton, Ont., but was caused by a series of computer failures on the space station.

NASA mission controllers eventually managed to get one of three balky computers on the station’s U.S.-built Destiny module working, but were unable to solve software problems on the other two until Saturday. Officials were unwilling to use the robotic arm without a back-up computer, comparing it to driving a car without a spare tire.

As it was, the station crew were instructed to move only one of the Canadarm2’s seven joints at a time to minimize the load on the troublesome computers. Mission controllers on the ground had to back up the station’s arm operator by verifying each command.

That made the handoff, in which the Canadarm2 passed off the cargo pallet in which it came into orbit to the Endeavour’s arm for storing in the shuttle’s cargo bay, a painstaking four-hour operation.

"Houston we have grapple," Col. Hadfield said after moving the shuttle arm to latch on to the pallet.

"OK, here we go," said Susan Helms, the space station crew member at the controls of the Canadarm2, as she began the final sequence of the handoff. "The brake lights are off."

After a long delay, mission controllers in Houston announced: "The first robotic handoff in space is complete."

Alain Dubeau, the manager of the Canadian Space Agency’s space station program, said that while the problem appeared to be on the station’s computers, built by Honeywell, NASA engineers were still not sure of the cause. "I’m not blaming the Americans," he said.

The Canadian Space Agency set up a parallel control room at its headquarters in St-Hubert, just outside Montreal, and its experts were on hand to assist Houston and allow the manoeuvre to go ahead.