Washington, Apr 11 (DPA): The US space agency NASA Saturday extended by one day space shuttle Discovery's mission at the International Space Station.

The move was made to allow an inspection of Discovery's heat shield while the craft is still docked at the International Space Station.

Discovery is now slated to land at Kennedy Space Centre in Florida April 19 at 8:54 am (1824 IST).

The inspection has been standard procedure since the space shuttle Columbia disintegrated on reentry into the Earth's atmosphere in 2003 after its heat shield was damaged.

The inspection is usually done after the shuttle undocks from the ISS, but problems with the Discovery's system that transmits videos from the shuttle back to Earth prompted NASA to do the check before leaving the ISS.

NASA is scheduled to retire its fleet of ageing space shuttles later this year, with just three more flights after Discovery aimed at transporting big ticket items to the space station. But the agency has indicated that flights could extend into early 2011 if delays are necessary.

Discovery has brought a new ammonia tank for the station's cooling system that astronauts are installing in a series of three spacewalks and an Italian-made equipment carrier. The next spacewalk is to begin early Sunday.