NASA managers are still debating whether to risk a space shuttle flight on a mission to extend Hubble's life:
The 16-year-old orbital observatory is expected to function for only two or three more years without a servicing call by space shuttle astronauts.
Scientists say equipment upgrades could keep the world's premier observatory operating until at least 2013.
"We haven't even approached the limits of what we can do with Hubble," senior project scientist David Leckrone with NASA's Goddard Space Flight Centre said.
