Cape Canaveral, Fla. ? The fate of what some scientists dub “the people’s telescope” is again up in the air as NASA decides soon whether to squeeze in a last astronaut repair mission to extend the life of the Hubble Space Telescope.

On Friday, NASA engineers will debate the safety of sending a fifth and final manned space shuttle flight to the 16-year-old telescope, probably in 2008. Soon afterward, NASA Administrator Michael Griffin will make the final call.

His decision could prolong Hubble’s ability to capture some the most spectacular images of the universe well into the next decade or allow the telescope to deteriorate into oblivion by 2009 or 2010.

Griffin worked on Hubble earlier in his career and recently described it as “one of the great scientific instruments of all time.” Unlike his predecessor, he has expressed a willingness to repair it.

“If we can do it safely, we want to do it,” Griffin said. “But we have new constraints on … the space shuttle system. We have a new understanding of its fragility and vulnerability.”

The final Hubble repair mission was canceled by former NASA Administrator Sean O’Keefe 2 1/2 years ago after the space shuttle Columbia disaster that killed seven astronauts in 2003. The ex-administrator cited the risk to astronauts and the need to use the remaining shuttle flights to finish building the international space station.

O’Keefe proposed using a robot to service Hubble, but a scientific advisory panel said the chance of completing such a mission on time was remote and that a manned mission had better odds of succeeding. The panel also said the risks of flying to Hubble weren’t much greater than going to the space station.

The primary concern lies with astronaut safety. If the astronauts go to Hubble, they won’t be able to seek refuge at the space station should there be a catastrophic problem like the one that doomed Columbia.

The remaining 14 shuttle flights are dedicated to completing the space station by the time the fleet is grounded in 2010. If a Hubble mission is approved, it would have to be squeezed into the shuttle schedule sometime in early 2008.