The scheduled launch Wednesday of the US space shuttle Atlantis could be delayed by Hurricane Lili, now churning toward the Gulf of Mexico, NASA officials said Monday.

The scheduled 11-day mission is the first since NASA grounded the US space shuttle fleet in July after finding cracks in their propulsion system.

Shuttle program manager Ron Dittemore said NASA intended to be “conservative” in its expectations for Wednesday’s launch from Kennedy Space Center “with that hurricane threatening the Gulf Coast” with winds of up to 120 kilometers (72 miles) an hour.

“We would not entertain launching until we are sure that that hurricane does not present a threat to our mission control center in Houston,” Dittemore said, anticipating that the 30 or so staff members may be sent home Wednesday if Lili continues on course.

National Aeronautics and Space Administration engineers have been working round the clock here to make sure the problems did not seriously hold up construction of the troubled International Space Station, already threatened by Russia’s financial woes.

“Engineering and ground processing teams have done outstanding work in the past few months to ensure the readiness of Atlantis for a safe flight,” said Dittemore.

“Atlantis is in great shape and ready to fly.”

The engineers had to weld over holes in the hydrogen flow liners of the propulsion system of Atlantis, Endeavour and Columbia.

Atlantis will be carrying a 15-meter-long (45-foot-long) arm for the space station, which will include part of its air conditioning system.

The Atlantis hold will be completely filled by the 12.5 million tonne, 390 million dollar aluminium structure, known as Starboard One.

The structure, known as a truss, will be moved out by Atlantis’ robot arm and attached to the space station during three six-hour sorties by the astronauts.

Mission commander Jeff Ashby, making his third flight in space, will be accompanied by four other Americans, Pam Melroy, the pilot, and technical specialists Sandra Magnus, David Wolf and Piers Sellers.

Wolf and Sellers will carry out the spacewalks to attach the structure.

They will be accompanied by Russian cosmonaut Fyodor Yurchikhin.

This will be the 26th flight by Atlantis and the 15th mission as part of the space station construction programme.