If all goes well, a crew of six astronauts will blast off from Kennedy Space Centers (KSC) launch pad 39-A about 1 p.m. Eastern Standard Time January 31 on an 11-day flight that would be capped with a landing back Endeavours Florida homeport at 5 p.m. February 11.

"Were getting back into the swing of things," said KSC spokesman Joel Wells.

Added Lisa Malone, chief of media services at KSC: "We still have a few more weeks of work to do to get ready for launch, but January 31 is a date we think we can make based on the work schedule."

That schedule now includes:

• A simulated-launch countdown drill to be held at KSC Tuesday. The idea is to "keep the launch control team [at KSC] fresh and on edge," Wells said.
• A crucial test Friday of the shuttles main propulsion system and three liquid-fueled main engines. Gaseous helium will be pumped through the system during the test in a search for potentially dangerous leaks.
• A three-day fuel-loading operation during which engineers will pump toxic rocket propellants into storage tanks that feed the shuttles twin maneuvering engines and its 44 nose-and-tail steering thrusters. The pre-launch propellant load will begin January 10 and conclude January 12.
• A two-day test that will be capped January 14 as the shuttles crew, led by veteran astronaut Kevin Kregel, board the $1.8 billion shuttle on the launch pad for the last three hours of a practice countdown.

Flying aboard Endeavour with Kregel will be copilot Dom Gorie and four mission specialists: Janet Kavandi and Janice Voss of NASA, Mamoru Mohri of the Japanese Space Agency and Gerhard Thiele of the European Space Agency.

Once in orbit, the astronauts will deploy a 200-foot-long radar antenna that will be used to make a three-dimensional map of about 80 percent of the surface of Earth.

Officials with NASA and the National Imagery and Mapping Agency a mission co-sponsor -- say the map will be the most complete and accurate ever assembled.

Originally scheduled for flight September 16, the mission was put on hold after an electrical short circuit knocked out two crucial engine computers during the July 23 launch of Columbia.

Triggered by a damaged wire within Columbias fuselage, the short circuit left an astronaut crew one failure away from an emergency landing, prompting NASA to ground all shuttle flights.

Fleet-wide wiring inspections and repairs were ordered and NASA managers ultimately decided to fly the Hubble telescope repair mission before Endeavours radar mapping flight.

Endeavours inspections and repairs largely are complete but the agency still faces at least one more major hurdle: Technicians still must inspect and make any necessary repairs within the shuttles cramped rear engine compartment.

Flawed wiring harnesses were uncovered during similar inspections as NASA readied Discovery for launch on the Hubble repair mission. The work within Endeavours engine compartment is scheduled to begin January 14 and will take about 10 days to complete.

"Well be going throughout the engine compartment, inspecting with a keen eye on wiring," said Wells. "Theres a more meticulous approach to the closeout work now to make sure the vehicle is ready from a wiring standpoint."

As it stands now, NASA will have opportunities to launch Endeavour on January 31 and February 1 before running into scheduling problems on the Air Forces Eastern Range.

A widespread network of ground stations, the Eastern Range provides rocket tracking and range safety services for all launches from Floridas Space Coast.

It typically takes 36 to 48 hours to reset range systems between launches of different vehicles, and two other commercial satellite-delivery missions now are scheduled for launch from Cape Canaveral Air Station in early February.

A Lockheed Martin Atlas rocket is scheduled to launch a commercial communications satellite February 3 and also has the 4th booked on the range for a next-day back-up launch opportunity.

A Boeing Delta rocket, meanwhile, is scheduled to launch four Globalstar cellular telephone satellites on February 6 and also has the next day booked on the range for a back-up opportunity.

Consequently, a shuttle launch delay beyond February 1 could force NASA to postpone Endeavours flight until February 9.