US shuttle Discovery could be back at "home" in Florida by the middle of next week, as Nasa makes final plans to fly it back from California on a 747 plane.
The shuttle is being serviced at a Nasa centre in southern California
Persistent bad weather at Discovery's intended landing site in Florida forced Nasa to bring it down at Edwards Air Force Base, California, last week.
Operations to prepare the vehicle for the flight back are running ahead of schedule, Nasa officials have said.
But it is likely to cost the agency at least $1m to fly the shuttle back.
Discovery will take-off from Edwards Air Force Base piggybacked on a specially modified Boeing 747 for the return flight to Kennedy Space Center, near Cape Canaveral, Florida.
Nasa officials said this "ferry flight" is now expected to occur no earlier than 16 August, but added that this could change.
Discovery's spent 14 days in space during its mission to resupply the International Space Station and test heat shield repair techniques. It was the first shuttle flight in the two-and-a-half years since the Columbia disaster.
After a perfect landing on 9 August, Discovery was towed to Nasa's Dryden Flight Research Center on Edwards Air Force Base.
Shuttle Endeavour mated to a 747 carrier on a previous flight
There, the shuttle was placed in its Mate-Demate Device, a large gantry-like structure used to service the vehicle and eventually mount it atop the 747 shuttle carrier aircraft (SCA) that will fly it home.
Vehicle manager Stephanie Stilson, who is overseeing the post-flight servicing operation, said crews had been working 24 hours a day on three shifts and were now ahead of schedule.
The technicians spent Friday drying the main engines and their associated plumbing to purge them of residual liquids.
They spent the rest of the weekend draining the shuttle's liquid hydrogen and liquid oxygen fuel tanks and removing hazardous monomethyl hydrazine fuel from the shuttle's propulsion system.
Inspections of heat shield tiles, panels and protective blankets that protected Discovery during its fiery descent through Earth's atmosphere on Tuesday are continuing.
The narrow section of thermal blanket spotted billowing out under a window during in-orbit inspections has been removed for analysis.
Shuttle managers were concerned it could tear off during re-entry and hit another part of the shuttle, but eventually decided not to repair it.
However, astronaut Stephen Robinson was sent on a spacewalk during the mission to remove two cloth fillers found sticking out between heat-shield tiles on the shuttle's underside.
Nasa has grounded all shuttle flights until it has fixed the foam debris problem which surfaced during Discovery's climb to orbit on 26 July. A 1lb (450g) chunk of foam peeled off the external fuel tank, narrowly missing the shuttle.
Last week, the agency said it was unlikely to complete the fix in time for a scheduled September flight of shuttle Atlantis.
A suitcase-sized piece of foam punched a hole in shuttle Columbia's left wing during launch in 2003, allowing super-heated gases to enter and tear the orbiter apart as it attempted to return to Earth 16 days later.