Canadian astronaut Julie Payette will have to wait to make her second trip to space, after NASA delayed the launch of the space shuttle Endeavour on Saturday because of a fuel leak.

But once she does ascend through the atmosphere, she will carry a piece of Ottawa Valley lore from a local museum.

Payette will have a copy of the brass astrolabe believed to have belonged to Samuel de Champlain as he explored the area 400 years ago. The navigational tool was likely dropped around 1613 during a portage around the Ottawa River's rapids at present-day Cobden, according to Museum of Civilization.

A 14-year-old farm boy found the astrolabe near Green Lake in 1867. It was in American hands until 1989, when it became part of the Gatineau museum's permanent collection.

Every astronaut is allowed a small space onboard to bring personal items. The actual astrolabe is too large to fit on Endeavour, so Payette will carry a smaller brass replica that remains fully functioning.

The device has an outer disk with the circumference marked in degrees, and a movable pointer in the centre. Explorers and navigators would align the astrolabe with the horizon and aim the pointer at the sun or a pole star to calculate latitude using an astronomical table.

Besides the replica astrolabe, Payette will also carry a rough diamond from the Northwest Territories, drops of water from the Great Lakes and Canada's three oceans, a Montreal Canadiens sweater autographed by Maurice "Rocket" Richard, and several other items.

Payette taking delay "in stride"

Payette, one of seven astronauts who have yet to suit up for the mission, will wait until NASA can schedule a new launch date for her crew's 16-day mission at the International Space Station.

NASA chose to halt Endeavour's mission after a potentially dangerous gas leak was found during fuelling, just after midnight.

Benoit Marcotte, the Canadian Space Agency's director of operations, says Payette is taking the delay in stride.

"We've had a message from her saying: 'Yes, we've scrubbed and that's something we're taking in stride as a team,'" Marcotte told The Canadian Press.

Marcotte said Payette and her fellow crew members remain "ready to launch," and that it is "normal in their business to have those kind of situations."

He said it is not clear when exactly Endeavour will be able to take off, as NASA has plans to launch a probe to the moon between June 17 and 18.

"That launch is pretty critical because it has to be timed perfectly with the alignment of the orbit of the moon," Marcotte said.

NASA has indicated that if Endeavour is unable to take off before Saturday, the launch will have to be rescheduled for a date in July.

A delay until the end of July would likely mean the entire shuttle program would have to be rescheduled. NASA is working on a tight schedule with a plan to retire the shuttle fleet and complete construction of the ISS by the end of 2010.

The leak that postponed Saturday's launch is almost identical to one that stalled a shuttle Discovery flight back in March.

NASA launch director Mike Leinbach said the leak is located at a vent line hookup on the fuel tank. The venting system is used to carry excess hydrogen safely away from the launch pad.

Hydrogen gas is extremely volatile and can burn in large enough quantities.

NASA's launch team immediately began draining Endeavour's external fuel tank and will spend the next few days examining the problem.

In March, the leak occurred where a vent line hooks up to the tank. The hookup was replaced along with a couple of seals and the seepage stopped, but engineers never did determine the exact source of the trouble.

Endeavour's mission

Endeavour is taking the final segment of Japan's huge space station lab and an outdoor shelf for experiments to the orbiting outpost.

The astronauts will also attach some spare parts outside the space station, replace aging batteries and perform other maintenance.

Payette's trip to the space station, her second trip in space, will be historic. She is due to join fellow Canadian astronaut Bob Thirsk, who boarded the space station on May 29 along with a Russian and a Belgian astronaut. He's living there for six months.

Endeavour's crew of seven will be aboard the space station for close to two weeks, during which five space walks are planned.

Payette is making her first trip to the space station since the Discovery mission in 1999 when she became the first Canadian to visit the outpost.

Since that trip, the space laboratory has grown to the size of two football fields.

The 45-year-old mother of two boys will be a shuttle flight engineer for the first time on the current mission, keeping busy by helping operate three robotic space arms.

One of them is the Canadarm1 on the shuttle and the other two, the Canadarm2 and a Japanese arm, are on the space station.

The Japanese robotic arm will be used to install a platform for experiments on the station's Japanese Kibo module.

Endeavour's flight comes three weeks after the successful repair effort at the Hubble Space Telescope carried out by Atlantis.

The mission may be the last time a Canadian flies on an American shuttle. The fleet is due to be retired in October 2010.

With files from CTV.ca and The Canadian Press