Space shuttle Atlantis and its six astronauts are now set to blast off from the Kennedy Space Center at 6:43 a.m. EST (1143 GMT) on March 15. Final approval of that date will be made at a meeting of NASA managers at the end of February.
"Everybody agrees that it was something that was doable if all other processing activities go smoothly," said NASA spokesman Kyle Herring in Houston.
The space shuttle mission is scheduled to last 11 days, although NASA is considering extending it to as many as 13 days to give the astronauts more time for their tasks.
The astronauts will deliver another solar array and truss segment to the space station, continuing an ambitious schedule to complete construction by 2010, when the shuttle program is to end, reports AP.
The launch window likely would close around March 25 so that Atlantis' visit to the space station doesn't interfere with the planned launch of a Russian Soyuz vehicle carrying new crew members to the space station. The Russians had planned to launch the Soyuz on April 9 but may bump up the lift-off by two days.
When asked about the prospect of a launch on the Ides of March, the fateful day Julius Caesar was assassinated, Herring said, "Superstitious is not in our vocabulary."