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The James
Webb Space Telescope's 21.3-foot-wide (6.5 meters) primary mirror is seen here
during testing on Earth. (Image credit: NASA/Chris Gunn) |
The deployment of mirrors is set to begin on Wednesday (Jan. 5).
The James
Webb Space Telescope is rapidly approaching its next major mission.
Webb
completed the most complex and difficult operation of the $10 billion
observatory's protracted deployment phase on Tuesday (Jan. 4), getting its
massive, five-layer sunshield up to the right tension.
As a
result, the mission team can move on to the next big task on its to-do list:
aligning the telescope's secondary and primary mirrors properly. And the ball
will start rolling on that pretty shortly.
"We just
finished deploying our sunshield, but there's more! The secondary mirror for
NASAWebb will be unveiled today, January 5th.
NASA
authorities announced the news on the mission's Twitter account on Tuesday
evening.
As Tuesday
progressed, the planned schedule appeared to shift. Mission team members, for
example, said during a news briefing early Tuesday afternoon that mirror
deployment would likely take a few more days.
During the press conference, Alphonso Stewart, the James Webb Space Telescope deployment systems director at NASA's Goddard Space Flight Center in Greenbelt, Maryland, remarked, "I would think probably by this weekend we will start that process." "However, it only lasts around ten days after that. The entire mirror deployment takes ten days."
Webb's primary
mirror, which is 21.3 feet wide (6.5 metres), is made up of 18 hexagonal pieces
arranged across a central platform and two smaller side "wings."
Prior to launch, these wings were folded back to let the unit to fit within
Webb's Ariane 5 rocket's protective payload fairing. (The sunshield, which is
about the size of a tennis court, had to unfurl after liftoff as well.) The
primary mirror is deployed by extending and locking the two wings in place.
Webb's
secondary mirror is named after the second surface that light will encounter on
its route into the telescope's four science instruments after the primary. The
secondary mirror is 2.4 feet wide (0.74 m) and rests at the end of numerous
booms that must be extended.
First, the
secondary mirror will be installed. This action is preceded by the heating up
of the motors that deploy the mirror structure, which Stewart predicted will
start on Tuesday night.
"We'll start heating [motors] in preparation for the wing mirror deployments in the next two days," he stated during Tuesday's news conference.
Webb's
timeline alterations are neither surprising nor alarming; team members have
highlighted that most deployment procedures are adjustable since the
observatory's launch on Dec. 25.
Webb is
meant to detect weak heat signals from the early universe, a difficult task
that necessitates keeping its optics and instruments extremely cold. That's why
the observatory has such a large sunshield and will be located at Lagrange
Point 2 (L2), a gravitationally stable point roughly 930,000 miles (1.5 million
kilometres) from Earth. Webb will remain aligned with Earth, the sun, and the
moon at L2, allowing the sunshield to continuously block light and heat from
these bodies.
If everything goes according to plan, the telescope will enter orbit around L2 29 days following launch, with an engine burn (on Jan. 23). Webb will have arrived to its final location at that point, with all main deployments completed. However, the observatory will not be ready to begin its scientific activities until later this year.
The
mission team will still need to check out and calibrate Webb's equipment, as
well as precisely position the 18 major mirror segments so that they work as a
single light-collecting surface. The completion of these projects will take
several months. The science operations are set to begin this summer and will
run for at least five years.
Originally Published on Space.com.
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