The latest problem with the Hubble Space Telescope did little to dampen enthusiasm among scientists for moving ahead with a planned space shuttle mission to refurbish the aging orbital observatory, even though that mission now will be delayed by several months.
The failure of a device called the Side A Science Data Formatter, used to send images and other data from Hubble back to Earth, is a problem, but likely one that can be fixed, NASA officials said. The problem was disclosed by NASA. Engineers now plan to switch the observatory over to a spare “Side B” formatter and perhaps send up a replacement device on the next space shuttle servicing mission, which had been scheduled for October but now has been delayed until early 2009.
Hubble managers hope to make a decision by Oct. 10 about when to make the switch to Side B.
Though it might sound like one setback too many for the observatory, which has been in orbit nearly two decades, scientists say Hubble still has a lot of life in it.
“Of course it’s worth upgrading Hubble,” said Mario Livio, an astrophysicist at the Space Telescope Science Institute in . “The part that failed even has a redundant side to it. If all goes well, science operations could be [back] up as early as the end of this week. So you shouldn’t worry about that. It’s definitely not the end of the world.”
The now-broken electronics box had been working steadily since the telescope launched in April 1990.
“These things happen. It’s been up there in orbit, outside the protective atmosphere of the Earth for 18 years,” said Heidi Hammel, an astronomer at the Space Science Institute in , “Glitches happen. It’s an incredibly robust instrument. Think about your computers – you don’t still use computers that are 18 years old.”
Rather than becoming discouraged about the latest glitch, some are celebrating the fact that it occurred just before a planned upgrade mission. If the malfunction had occurred after the shuttle mission to Hubble, then operations still could be switched over to the redundant part on board, but that would leave the telescope without a backup if that part failed again, or if the spare part did not work at all. Now, though, scientists have the option of sending up a new device to replace the broken one, leaving the telescope in a less vulnerable position.
“It’s probably better it failed now than the week after the servicing mission was done, but it does frustrate all of us that were looking forward to a mission two weeks from now,” Hammel said in a phone interview. “But I’d rather we’d waited and did it right.”
For every month NASA delays the shuttle servicing mission, Hubble’s cost jumps by $10 million, the amount needed to keep ground systems running and a team in place. But telescope team members argue that the additional cost is still worth it.
“I don’t see this failure as putting us over the fence and causing NASA to want to throw up its hands and say, ‘Hey, all the hundreds of millions of dollars we’ve spent on the hardware and readiness for this mission, we’re just gonna chuck it, you know, this is just a little too much for us,’” Preston Burch, Hubble manager at NASA’s Goddard Space Flight Center in Greenbelt, Md., told reporters during a teleconference Sept. 29. “We’ve got a lot of options here. I don’t see [NASA officials] Ed Weiler and Mike Griffin or myself throwing in the towel because we’ve got to spend a few more tens of millions to pull this mission off. You know, I think we’re definitely going after this.”
Since all of the instruments planned to be installed during the servicing mission already have been built, and most of the training and preparations for the upgrade made, calling it off now would be a waste, in the view of many scientists. “We’ve got these new instruments that are ready to go, they’re down there ready to fly,” Hammel said. “I think it’s absolutely worthwhile.” Nevertheless, some critics have questioned the wisdom of investing in keeping the aging Hubble going, instead of spending money to build a brand new telescope to replace it.
Hubble has cost about $10 billion so far, including past servicing missions, said Ed Weiler, associate administrator of the Science Mission Directorate at NASA Headquarters in . Its initial cost was about $1.6 billion, he said.
Given that the upcoming servicing mission will cost about $900 million, it could be seen as a bargain compared to building and launching a new observatory from scratch. “The thing about telescopes is that the mirror is the main component,” Hammel said. “Once that’s built, you don’t need to build new ones, you just need to swap out the instruments. There’s nothing wrong with Hubble’s mirror. It’s great.”
She compared a telescope with a working mirror to an old car with a good engine left. It makes more sense to swap out tires and other elements of the car than to simply buy a new one, since the most important element still functions fine. “If at some point, there’s a glitch that is not recoverable, then you’re done, but as long as the glitches can be solved and repaired, it’s sort of like an old car – you don’t want to let it go when it’s still running,” she said.
And the upgrades to Hubble aren’t coming at a sacrifice to building new telescopes. Plans for the James Webb Space Telescope are progressing; the roughly $4.5 billion observatory currently is slated to launch in 2013. However, that observatory will work in the infrared range of light, rather than the visible like Hubble, so James Webb is not really a replacement for Hubble, but a parallel instrument.