WASHINGTON  The many moving parts of a mission to shoot down a dying spy satellite with an anti-missile interceptor lined up Wednesday after the space shuttle Atlantis returned to Earth, officials said.

Military officials were reviewing the weather in the Pacific Ocean to determine if the operation could be launched overnight on Wednesday, as rough seas west of Hawaii prompted officials to caution that the attempt to destroy the satellite, carrying 1,000 pounds of toxic rocket fuel, might be delayed.

The goal of the mission is to prevent the fuel tank from reaching Earth and spilling its hazardous contents in a populous area. In the event that any of the hydrazine fuel falls on a populated area, the Federal Emergency Management Agency on Wednesday issued directions to community first responders on how to deal with dangerous debris from the satellite.

Military officials said their goal was to carry out the mission before March 1, when the satellite is predicted to start skidding against the upper reaches of the atmosphere. That initial friction would bump the satellite into a more unpredictable orbit around the Earth, even before it starts a fiery descent through the atmosphere.