MOSCOW, September 1 (RIA Novosti) - NASA has postponed the Atlantis shuttle's launch to the Hubble Space Telescope for another two or three days to October 10-11, to complete work on an external fuel tank.

During 'Servicing Mission 4', originally scheduled for launch on August 28 but postponed until October 8, the shuttle's seven-member crew will install new instruments, replace degraded systems, and "bring inactive instruments back to life", NASA said in a statement.

The space agency said Hubble, orbiting 569 km (353 miles) above the Earth, is the first telescope designed to be visited in space by astronauts to perform repairs, replace parts, and update its technology with new components.

It is a large, space-based observatory which in its 18 years of operations has provided astronomers with deep and clear views of outer space, from our own solar system to remote galaxies.

Launched in 1990 and substantially upgraded through new instrumentation installed during four previous servicing missions with space shuttles, Hubble completed its 100,000th orbit of Earth on August 11.

The upcoming mission will be the final trip to Hubble, bringing about 22,000 pounds of hardware to the space telescope.