After years of busted budgets and stretched timelines, NASA says its $8.8 billion James Webb Space Telescope is ready for testing and on track for launch in 2018.
The telescope, seen as a successor to the Hubble Space Telescope, is designed to capture images of the first galaxies ever formed and provide unprecedented data about planets circling distant stars.
“Today, we’re celebrating the fact that our telescope is finished, and we’re about to prove that it works,” Nobel-winning astrophysicist John Mather, the telescope’s senior project scientist, told reporters at NASA’s Goddard Space Flight Center in Maryland today.
NASA has completed an initial round of laser-based optical measurements, known as a Center of Curvature Test, to determine that the telescope’s 18 hexagonal mirror elements are precisely aligned to produce sharp images.
In the months ahead, the mirror will be subjected to the stresses and strains it’s expected to experience during launch. Then the mirror’s alignment will be checked again to make sure it’ll work correctly in space.
NASA also says the fifth and last layer of the telescope’s sunshield has been completed and delivered to a facility in California. The reflective, foldable sunshield is designed to keep the telescope’s sensitive electronics and optics from overheating.
Eventually, all the components will be combined to create the finished telescope, and then loaded onto a European Ariane 5 rocket for launch in October 2018. The telescope will be sent to a gravitational balance point beyond Earth known as Sun-Earth L-2.
The telescope is designed to be tuned remotely by mission controllers back on Earth – but it’s not designed to be repaired by a visiting crew of astronauts, as was the case for Hubble. That means it’s important for NASA to make sure no unfixable glitches come to light after liftoff.
“If you really care about something, you’ve got to measure it at least twice,” Mather said, “and if you don’t get the same answer, you better figure out why.”
When the Webb telescope was conceived in the mid-1990s, NASA expected it to cost somewhere around $1.6 billion and go into operation around 2011. The project ran into cost overruns and schedule setbacks, however. Five years ago, it came close to being canceled.
“It almost didn’t happen,” NASA Administrator Charles Bolden acknowledged at Goddard Space Flight Center.
Congress agreed to keep the program alive but set an $8 billion cost cap for mission formulation and development.
Today Bolden said he was “very confident” that the telescope was on budget and on track – and in response to a question, he said the James Webb Space Telescope should get off the ground on time no matter how next week’s presidential election turns out.
“We made a commitment of a schedule and time, and we have been on that for about six years now,” Bolden said. “So I think the story we have to tell, the record of performance that we have, should stand us in good stead. I think anybody would be crazy to tell you that anything survives over a transition, but I’m comfortable, as I am about most of what NASA’s doing today, that we’ve got a good story to tell and a record of performance.”