"Thats about $6 billion spread out over 30 years," he said. "And that equates to about two cents a week per American taxpayer over that period of time."

Hubble is flying idle now in an orbit 350 miles above Earth. The celestial spyglass was temporarily knocked out of commission in November by a pointing control system failure. The cost of keeping vigil over Hubble until its fixed: About $550,000 a day.

A telescope repair crew is scheduled to be launched on Dec. 9 aboard Space Shuttle Discovery. The space agency is spending about $205 million to stage the mission. That total includes $110 million to launch the shuttle and its seven-member crew, which includes four spacewalking repairmen.

Another $69 million is being spent to outfit Hubble with new equipment and service various telescope systems. Those costs include:

• $8 million for a full set of six gyroscopes: Housed in electronics boxes the size of carry-on suitcases, the devices enable Hubble to lock on to stars, planets, galaxies and other celestial objects. Three gyroscopes are required to operate the observatory. Four, however, have failed over the past few years, triggering the recent observatory shutdown in orbit.
• $13 million for a refurbished fine guidance sensor: Shaped like a baby grand piano, the sensor gives Hubble the ability to remain locked onto an astronomical target for days at a time. The resulting stability can be compared to holding a laser beam on a dime that is 200 miles away, or the distance between Washington, D.C. and New York City.
• $7 million for an advanced computer that will be 20 times faster and have six times as much memory as the unit now aboard Hubble.
• $11 million on a new solid state recorder, radio transmitter, voltage regulators and thermal blankets that protect the telescopes sensitive instruments and electronics from the harsh space environment.
• $24 million to develop computer software for the servicing mission.
• $6 million for Hubble simulators and testing.

NASA originally had planned to fly a Hubble servicing mission in June 2002 but the launch campaign was accelerated in February after a third gyroscope failed. The costs associated with putting the mission on a fast track include:

• $19 million to add an extra Hubble servicing mission to NASAs shuttle flight schedule.
• $7 million to switch the hurry-up mission to shuttle Discovery. The June 2000 flight had been slated to launch on sistership Columbia, which now is undergoing a long-delayed overhaul at a shuttle assembly plant in Palmdale, Calif.

Weiler and other NASA officials say the cost of the rescue mission is a small price to pay to resuscitate a telescope that is forcing scientists to rewrite astronomy books and rethink longstanding theories about the nature of the universe.

"We have a large amount of money invested in this project, and this mission will keep the scientific dividends flowing," he said. "This mission is really to protect the science, to protect that investment."