NASA’s new space telescope is on the verge of completing the riskiest part of its mission — unfolding and tightening a huge sunshade — after ground controllers fixed a pair of problems, officials said.
The tennis-court-size sun shield on the James Webb Space Telescope is now fully open and in the process of being stretched tight. The operation should be complete by Wednesday.
The $10-billion telescope — the largest and most powerful astronomical observatory ever launched — rocketed into space on Christmas Day. Its sun shield and primary mirror had to be folded to fit into the European Ariane rocket that carried it into space.
The sun shield is vital for keeping Webb’s infrared-sensing instruments at subzero temperatures as they scan the universe for the first stars and galaxies, and examine the atmospheres of alien worlds for possible signs of life.
Getting the sun shield extended on Friday “was really a huge achievement for us,” said project manager Bill Ochs. All 107 release pins opened properly.
But there have been a few obstacles.
Flight controllers in Maryland had to reset Webb’s solar panel to draw more power. The observatory — considered the successor to previous space telescopes including the aging Hubble — was never in any danger, with a constant power flow, said Amy Lo, a lead engineer for the telescope’s prime contractor, Northrop Grumman.
They also repointed the telescope to limit sunlight on six overheating motors. The motors cooled enough to begin securing the sun shield, a three-day process that can be halted if the problem crops up again, officials said.
“Everything is hunky-dory and doing well now,” Lo said.
Ochs expects the tightening of the sun shield to be drama-free.
“The best thing for operations is boring, and that’s what we anticipate over the next three days, is to be boring,” he said in a teleconference Monday.
If that holds true, the telescope’s gold-plated mirror — which measures more than 21 feet across — could unfold as soon as this weekend.
Webb should reach its destination 1 million miles away from Earth by the end of January. As of Monday, the telescope was more than halfway there.
The infrared telescope should begin observing the cosmos by the end of June, ultimately unveiling the first stars and galaxies formed in the universe some 13.7 billion years ago. That’s a mere 100 million years after the big bang.
Hubble, which sees primarily visible light, has peered as far back as 13.4 billion years ago. Astronomers intend to see even farther — in distance and back in time — with the Webb, which detects infrared light and is 100 times more powerful.
In another bit of good news Monday, officials said they expect Webb to last well beyond the originally anticipated 10 years based on its fuel efficiency.