NASA managers, wary of the approaching tropical storm, Ernesto, has postponed its decision on whether to keep the space shuttle Atlantis at the launch pad or indoors or roll it back to the assembly facility. Decision should be made Monday.
NASA is keeping an eye on tropical storm, Ernesto, which is now predicted to strike the west coast of Florida later this week.
Atlantis sits on the launch pad at the moment, ready for Tuesday's launch to make a scheduled journey to the international space station.
But NASA associate administrator Bill Gerstenmaier says mission controllers are considering either leaving the shuttle on the launch pad or rolling it back into the assembly building.
"We're protecting those two options to the best of our ability," said Bill Gerstenmaier. "And that's what we're doing as a team. If you had to pick a perfect training scenario, this is probably the most awesome training scenario I've ever seen."
If NASA cannot launch Atlantis at all this week, a second attempt will be made the week of September 7.
That would require an agreement with the Russians, who would have to delay their launch of a Soyuz capsule carrying a replacement crew to the international space station.
The Russians are also unhappy about the fact that a launch after September 7 would mean a middle-of-the night landing for the returning crew.
So far, Gerstenmaier says NASA officials are in discussions with the Russian space agency.
"It won't be the Russians saying no," he said. "It will be us collectively as the international space station team saying this is the right thing to do for the international space station."
Construction of the space station has been on hold since the 2003 disintegration of space shuttle Columbia, which killed seven astronauts and grounded the shuttle launch program.
This is the first of 15 scheduled flights by Atlantis to finish constructing the orbiting scientific laboratory by 2010, when the space shuttle program is retired.