Never has the phrase been more apt: What a long, strange trip it's been. From big bangs to infinitesimal molecules, the Hubble Telescope has been parsing The Great Beyond for nearly two decades now, but its last hurrah is quickly approaching. In the northwest corner of the Johns Hopkins Homewood campus, scientists at Hubble's mother ship, the Space Telescope Science Institute (STScI), are confabbing with NASA as the agencies prepare for Hubble's final scheduled servicing mission on October 10. This fifth servicing will give Hubble a sendoff worthy of its success in space.
Yes, success. Despite early missteps and outright failures, Hubble has exceeded expectations. Of course, the story of Hubble's problematic beginning is now the stuff of modern scientific legend. Shortly after its 1990 launch, critics excoriated the mission when its 2.4-meter-diameter mirror was found to be flawed, resulting in blurry images of the cosmos being sent back to Earth. After an extended period of public flogging, NASA sent up its first servicing mission in 1993 to correct the mirror's irregularities. The resulting data and pictures forever changed the way we viewed the universe and measured our origins. Hubble helped date the age of the universe (12-13 billion years), verify the existence black holes, and document "white dwarfs," the oldest, faintest stars in the Milky Way.
Even so, Hubble's life was slated to be cut short following the 2003 Columbia shuttle disaster. In the immediate aftermath, then NASA administrator Sean O'Keefe wanted to end servicing missions, deeming them too dangerous. Backed by intense lobbying on the part of scientists and citizens, Hubble found a fairy godmother in Maryland Senator Barbara Mikulski. The senior Democrat on the subcommittee that approves NASA's budget, Mikulski took to the senate floor, calling Hubble the catalyst for the "Golden Age" of astronomy, noting that its data had yielded more than 2,600 scientific papers. She even played the kid card, saying children constantly e-mailed the satellite questions such as "Did you see God today?" In the end NASA relented and reinstated Hubble's servicing—with one catch: When the space shuttle Atlantis heads skyward, for the first time, "there will be a rescue (shuttle) on the launch pad, just in case it's needed," says STScI astrophysicist and public outreach coordinator Dr. Mario Livio, who notes that the orbit of servicing missions doesn't allow astronauts to reach the safety of the Space Station if serious trouble arises.
If all goes as planned, Atlantis's crew will install several new instruments, fix a few failing ones, capture the bus-sized Hubble in the shuttle's cargo bay and bring it to a new higher orbit, and place a "soft capture" apparatus on the telescope. Attached to the aft-end of Hubble, the soft-capture device lets NASA attach a robotic steering tool. The idea is to guarantee Hubble lands in the sea when it comes crashing back to Earth as scheduled around 2020. It's no small concern, as some of Hubble's larger parts—notably its main mirror—may well survive re-entry.
"I don't mean to make light of it, but I'd be delighted if a piece of Hubble fell in my backyard," chuckles STScI news director Ray Villard. "It would be a real collector's item and I'm sure there'd be some interest on eBay."
But don't fire up your metal detectors just yet.
"It won't happen," assures Villard.
Livio says that the mood at STScI for Hubble's finale is more one of excitement than melancholy, despite the fact that many people at STScI have spent the bulk of their professional lives consumed with the satellite's operations. The fact that Hubble has performed far better than expected—Widefield Planetary Camera 2, responsible for so many incredible cosmic shots, has functioned for 15 years when its predicted life span was five—is a huge source of staff pride.
While Livio admits that, "We'll have some sort of farewell party," for Hubble, his colleagues are already looking beyond the telescope to its successor. "We have an encore," says Livio, "The James Webb Space Telescope, to be launched in 2013," right about the time Hubble is scheduled to go offline.
Think of the Webb as Hubble on steroids: With a mirror more than twice as wide as Hubble's and orbiting at a million miles from Earth (Hubble's orbit is only 350 miles above terra firma), Webb will boldly go where. . .well, you know the rest. Unlike Hubble, which works mostly with visible light, Webb is designed primarily as an infrared telescope. "If you want to look at the very, very distant universe, the very first galaxies, you need to look in the infrared," says Livio.
"We will be able to look into 'dusty' environments—new stars, centers of galaxies—that we cannot see with visible light, in particular, where planets are forming," he enthuses.
From premiere to final curtain, Hubble's glimpse into the extraordinary will have cost seven billion dollars. Will Hubble be worth it? To this, Livio just smiles. "It's as I told 60 Minutes," he laughs.
"It gave us the universe."