A NORTH-EAST astronaut was last night still unsure where he and his space shuttle colleagues will touch down.

Bad weather could force the shuttle Discovery, whose crew includes Saltburn-born Dr Nick Patrick, to land at one of three "imperfect" sites tonight.

The seven astronauts on board are scheduled to touch down at 9.56pm British time at the Kennedy Space Center, in Florida. Yesterday morning, commander Mark Polansky and pilot Bill Oefelein checked Discovery's systems and jets that will be used in the de-orbit burn and landing.

Nasa managers have been left with a headache over three choices of landing sites because of bad weather.

The forecast is for low clouds and showers at the Kennedy Space Center, where the space shuttle is meant to land.

Conditions are also unfavourable at the back-up landing site, Edwards Air Force Base, in California, where crosswinds are expected.

And although the forecast looks good at a seldom-used back-up site in New Mexico, its lack of equipment would give Nasa logistical headaches it would rather avoid.

Spokesman Phil Engelauf said: "More than likely, we will evaluate the conditions on a case-by-case basis on Friday and pick the lesser of evils."

During their last full day in space, after a 12-day mission, the seven astronauts were planning to test the shuttle's flight control system, stow items, deploy a small satellite and give their last media interview from space.

Engineers were expected to give the go-ahead for Discovery to come home after studying images the crew took of the shuttle on Wednesday.

Nasa wants the shuttle on the ground no later than tomorrow because the fuel that generates electricity on the spacecraft will run out.

The space agency has seven chances to land the shuttle today and tomorrow at any of the three sites.