NASA has delayed the launch of the space shuttle Endeavour until Sunday evening.

On Saturday morning NASA announced the delay, which is the result of thunderstorms in eastern Florida. The agency has ordered its engineers to give Endeavour a thorough going-over after nine lightning strikes near the launch pad on Friday afternoon.

The next launch attempt will be at 7:13 p.m. Sunday.

Montrealer Julie Payette and her six American crew mates arrived at Cape Canaveral Tuesday afternoon to prepare for the launch.

A hydrogen gas leak led to back-to-back launch delays last month while the spacecraft was being fuelled.

The Mission

The Endeavour crew will deliver the final segment of a Japanese lab along with hundreds of kilograms of food to the International Space Station and will participate in several space walks during the 16-day mission.

The Canadian Space Agency says Payette will operate all three robotic arms -- Canadarm, Canadarm2 and the Japanese arm -- during her visit to space.

Will join Thirsk on board

When Payette joins Robert Thirsk at the station, it will mark the first time Canada has two astronauts in space at the same time. Thirsk, who arrived May 29 on board a Russian Soyuz spacecraft, is spending six months at the space station.

Thirsk is laying the groundwork for the deployment of Canadian robots on other planets and figuring out how to help people adapt to extreme environments.

Eight launches remain before the three shuttles -- Endeavour, Atlantis and Discovery -- are due to be retired at the end of 2010.

With files from The Canadian Press