LONGUEUIL, Que. — Julie Payette wrapped up her second-ever visit to the International Space Station on Tuesday, bidding farewell to her fellow Canadian astronaut Robert Thirsk before making the journey back to Earth.

Payette was the first Canadian to visit the space station back in 1999, when it was a more bare-bones operation than it is now.

During this most recent mission, the 13-person crew made improvements to the giant orbiting lab, conducted experiments and did maintenance.

"Endeavour on the big loop -- tally ho," an Endeavour crew member radioed to NASA mission control as the space shuttle passed over Houston, Texas, after undocking from the space station.

The departure was broadcast on NASA TV and was also beamed live to the Canadian Space Agency in Longueuil, near Montreal.

Payette's arrival on the space station and her link-up with Thirsk about two weeks ago was the first time Canada had had two astronauts in space at the same time.

Thirsk has already spent seven weeks circling the Earth and performing a number of experiments, including studying the effects of weightlessness.

He will spend a total of six months on the station and is slated to return in November. Before that, he will help Quebec billionaire Guy Laliberte when the Cirque du soleil founder becomes the latest space tourist.

The withdrawal of the shuttle from the space station on Tuesday looked like a ghostly ballet as the hulking spacecraft pulled away, framed against the wispy white clouds and deep blue seas of the Earth below.

"We'd like to bid you farewell and fair sailing," a transmission from an Endeavour crewman to the space station said, giving thanks to the space station crew for their help and hospitality.

A space station crewman wished the Endeavour "Godspeed" in its return to Earth, adding the station "seems awfully big without you."

The Endeavour is due to land in Florida on Friday.

The shuttle almost looked like a shark skimming the surface of cloudy water as it passed under the space station in a circuit that gradually moved it away from the lab, travelling at what looked like incremental distances to the naked eye.

Images of the departure were transmitted to Earth from the shuttle and the space station.

Very little was said between the ground controllers and the astronauts, with information on the progress of the flight being made in short bursts of calm, almost monotone conversation.

Locations were noted, with controllers announcing when the spacecraft passed over several U.S. states, Mexico, the Equator, Ireland and parts of Canada including Quebec.

The shuttle seemed to be relying on gravity for propulsion, although it fired its rockets in short bursts -- one lasting only six seconds -- to separate from the station.

Payette and her six fellow crew members on Endeavour will keep busy before they are scheduled to land at the Kennedy Space Center.

They must inspect the shuttle to ensure its thermal shields were not broken by small meteors or space debris.