US space shuttle Discovery returned to earth safely at 7:01 p.m. local time Monday (0001 GMT Tuesday) at Kennedy Space Center after successfully completing an eight-day mission.

The return ended the three-flight 1999 agenda of the National Aeronautics and Space Administration (NASA).

The space travel, originally scheduled for mid-October, finally started on December 19 after nine delays. Although NASA officials said the space shuttle was immune from the Millennium Bug, the planned 10-day flight was cut to eight days to ensure its return before the arrival of 2000 to avoid possible Y2K problems.

The major task of the eight-day flight was rescuing the failing Hubble telescope through three spacewalks. The telescope had stopped working since mid-November after four of its navigational gyroscopes went wrong.

The astronauts replaced six gyroscopes in Hubble with new ones in the first spacewalk. A more powerful CPU chip was installed in it in the second walk.

Spacewalk three had a radio transmitter, a digital recorder and anti-rays sun shades put in the three-billion-dollar telescope.

The refurbished telescope was then released back into the orbit on December 25.

Scientists will test the telescope within the next two weeks and it is expected to resume space explorations on January 9, said NASA.

Hubble has served in space for nearly 10 years since it was first launched in 1990, sending more than 259,000 valuable pictures back to earth. (Xinhua)