NASA on Monday delayed the final service mission of the Atlantis space shuttle to the Hubble space telescope, probably until early 2009, after a "significant anomaly" occurred on the orbiting telescope.

"It's obvious that October 14 is off the table" for launching Atlantis, John Burch, the shuttle program manager at NASA's space center in Houston, Texas, told a telephone news conference.

The most likely new launch date for the mission to Hubble would be in February next year, the officials said.

On Saturday, Science Data Formatter side A, the unit on Hubble that took data from five instruments, formatted it and sent it back to the ground, providing NASA with spectacular images of space, "totally failed," Preston Burch, Hubble manager at Goddard space flight center near Washington said.

NASA was working to get Hubble back up and "doing science" in a matter of days by reconfiguring a unit on Hubble that has laid dormant during the 18 years that the telescope has been in orbit, to do the work of the failed unit.

But that would require some complex manoeuvers and would only be a stop-gap measure, the scientists said.

"If we just switch over to Side B of the Science Data Formatter, we would be left with a system that has several single-point failures, and that would be a risk to the mission for the long duration," said Ed Weiler, associate administrator of the Science Mission Directorate at NASA headquarters in Washington.

"Barring some unforeseen circumstance, our plan right now is to take the delay and put up the new hardware so that we can keep Hubble going as long as possible," he said.

"If we're going to spend the money and take all the risk involved in a shuttle mission we want to make sure that we leave Hubble as healthy as we possibly can and potentially locked in for the next five to 10 years," Weiler said.

Hubble is due to be replaced in 2013 by a new space telescope with an eagle-eyed camera that scientists hope will lift the veil from the origins and mysteries of the universe.

Every month that the service mission to Hubble is delayed represents a cost to NASA of around 10 million dollars, the officials said.

But the extra cost was unlikely to prompt the US space agency to "throw up its hands and abandon Hubble," Weiler said.

"I don't see anyone throwing in the towel because we have to spend a few more tens of millions to get this done," he said.

"Think about the other option -- if this failure had occurred two weeks after this last service mission," he said.

Launched 18 years ago, Hubble revolutionized astronomy by peering deep into the universe, beaming back dazzling images free of the distortions from Earth's atmosphere.

Orbiting 575 kilometers (360 miles) above Earth, Hubble has enabled scientists to better measure the age and origins of the universe, observe distant supernovas, and identify and study bodies in and outside the solar system.

All that, in spite of the Hubble program being declared dead in 1990.

"Not only did it survive, but we became the great American comeback story," Weiler said.

"Hubble has a habit of coming back from adversity... we'll find a way to get this fixed," he said.

"Luckily we have a spare. We have to test it out and do due diligence to make sure it's working right, but we do have a spare on the ground. We anticipated this kind of problem 20 years ago," he said.