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 Monday.
The tennis court-size sunshield 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 away Christmas Day from French Guiana.
Its sunshield and primary mirror had to be folded to fit into the European
Ariane rocket.
The sunshield 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 sunshield extended last 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 the aging Hubble Space
Telescope—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 sunshield, 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 sunshield 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 told reporters in a
teleconference.
If that holds true, the telescope's gold-plated mirror—more than 21 feet
(6.5 meters) across—could unfold as soon as this weekend.
Webb should reach its destination 1 million miles (1.6 million kilometers)
away 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 13.7 billion years ago. That's a mere 100 million years after
the universe-creating Big Bang.
Launched in 1990, Hubble, which sees primarily visible light, has peered as
far back as 13.4 billion years ago. Astronomers hope to close the gap with
Webb, which 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.
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