GREENBELT, Maryland <$>— NASA said yesterday it would extend the life of the Hubble Space Telescope until at least 2013 in a decision that involves a potentially risky space shuttle mission.

A space shuttle will make one final maintenance trip, tentatively in 2008, to the orbiting telescope even though astronauts will not be able to take shelter on the International Space Station if something goes wrong, NASA Administrator Michael Griffin told cheering scientists at the Goddard Space Flight Center outside Washington. “The desire to preserve a truly international asset like the Hubble Space Telescope makes doing this mission the right course of action,” Griffin said.