Oct. 27, 2006 — After all the time, money, anguish and work to return the space shuttle fleet to flight, NASA still has one lingering question to resolve: can a shuttle mission be sent to save Hubble?
If not for the 2003 Columbia disaster, the fifth servicing call to the Hubble Space Telescope probably would have happened by now. That mission would have left the 16-year-old observatory with fresh batteries, replacement gyroscopes for steering and two new science instruments.
Such upgrades could keep Hubble on the cutting edge of astronomical research, delving into questions such as the nature of the mysterious dark energy that seems to be driving the universe's expansion and what the universe looked like as its earliest structures emerged after the Big Bang explosion.
After the Columbia accident, however, shuttle flights that do not go to the space station, where astronauts can seek shelter in case their ship is too damaged to fly home, were considered too risky and the Hubble house call was canceled.
NASA looked into a robotic servicing mission instead, but found the cost and complexity of such a mission too daunting.
Meanwhile, public outrage over NASA's decision to let the popular space telescope go festered, culminating in a pledge by the new head of NASA to re-consider flying one last flight to Hubble.
Now, with three post-Columbia flights complete, the time has come to decide Hubble's fate. NASA plans a meeting today to consider if the safety upgrades implemented after the accident offset the risk of flying with few options available to save a stranded shuttle crew.
"Hubble is definitely sort of the comeback kid, so hopefully it will be able to do it one more time," said Adam Riess, an astronomer with the Space Telescope Science Institute in Baltimore, Md.
"I would expect that this is the final meeting," he added. "Now it's a matter of coming up a with a decision."
Shuttle program workers have certainly done their homework.
The first order of business was to fix problems with debris falling off the ship's fuel tank during launch.
A chunk of insulating foam broke off Columbia's tank during liftoff and smashed a hole in the wing's heat shield. As the shuttle attempted to return to Earth 16 days later, superheated atmospheric gases blasted into the breach, destroying the shuttle and killing the seven astronaut crew.
NASA's first tank redesign, tested during a July 2005 flight of shuttle Discovery, failed to prevent dangerously large pieces of foam from falling off the tank. A second redesign was tested a year later, and this time the tank was deemed safe enough to resume flights.
