Photo taken on Aug. 6, 2005 after Discovery undocks from the International Space Station. Discovery is returning home today.

    CAPE CANAVERAL, the United States, Aug. 8 (Xinhuanet) -- NASA announced early Monday that Discovery's planned landing was postponed by about 90 minutes to 6:22 a.m. EDT (1022 GMT) due to weather conditions.

    The decision was taken due to low clouds over the Kennedy Space Center (KSC) in the southern US state of Florida.

    If weather conditions are unfavorable for a landing on Monday, the orbiter has two more days to return to the KSC, or head to alternate sites either in California or New Mexico.

    Discovery is returning home after a 13-day mission, during which they transferred more than 1.3 tons of much needed supplies and equipment to the International Space Station, and carried awayabout 2.3 tons of garbage dumped over the past more than two years.

    The other prime task of the shuttle mission was to test the safety improvements NASA made since the 2003 Columbia disaster.

    Discovery astronauts, Stephen Robinson and Soichi Noguchi, conducted three spacewalks during the mission.

    This was the first space shuttle flight since the Columbia disaster on February 1, 2003. Enditem