BEIJING, Aug. 12 (Xinhuanet) -- Circling the Earth at nearly eight km per second since its launch in April 1990, the Hubble Space Telescope passed the 100,000-orbit mark on Monday, according to NASA.

    Scientists targeted Hubble's camera eye at part of a nebula near the star cluster NGC 2074 about 170,000 light-years from the Earth to celebrate the event.

    "That's a lot of orbits and that represents a lot of miles and a lot of time," said HST deputy senior project scientist Malcolm Niedner. "It's been just a fabulous long journey of scientific discoveries, with more to come."

     The telescope is still going strong after 18 years in orbit in spite of micrometeorite impacts and temperature extremes. It has contributed to thousands of scientific discoveries.

    "It's explored entirely new grounds in terms of the ability to see things in detail, and what has resulted from that is just marvelous," said Bob O'Dell, Vanderbilt University in Tennessee. O'Dell started as a NASA project scientist for Hubble 19 years before its launch and helped to get the project off the ground.

    Because it views from space, beyond Earth's atmosphere, Hubble can out perform ground-based observatories much larger than it in terms of resolution, scientists said.

    In October, the observatory will have its fifth, and final, face-lift. By then, the space shuttle Atlantis will visit the orbiting scope. Astronauts plan to install new equipment and repair broken instruments during five spacewalks.

    The tune-up should extend Hubble's life until at least 2013 when, the scientists expect,  NASA's shuttle fleet will likely be retired and the telescope could face destruction by burning up in the atmosphere during a controlled dive down to Earth.

    (Agencies)