NASA’s next large space observatory is finally up high, but it will be some time before it begins its much-anticipated science mission.
The 10 billion dollars James Webb Space Telescope launched Atop an Ariane 5 rocket from French Guiana yesterday (December 25), embarking on a long-delayed, potentially transformative mission to study the early universe, nearby exoplanets, and more. Telescope team members (and the rest of us) will have to be patient, however, and Webb has a lot of work to do before it goes live.
The telescope is heading towards SunEarth Lagrange Point 2 (L2), a gravitationally stable spot 930,000 miles (1.5 million km) from our planet in the direction of Mars. It will take Webb 29 days to get there, and there will be plenty of nail-biting telescope action along the way.
“Webb has 50 major deployments…and 178 launch mechanisms to deploy those 50 fragments,” said Webb mission systems engineer Mike Menzel of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.29 days on the edgepublished by the agency in October.
«Every one of them has to work,» Menzel said. «Web publishing is the most complex spacecraft activity we’ve ever done.»
Webb has already achieved some major milestones. About half an hour after takeoff, for example, it deployed its solar panels and began absorbing energy from the sun. And last night, the large telescope conducted a Critical 65 Minutes Burning Engine Which I put on course for L2.
Here is a brief summary of the big strides yet to come. (For more details, see the NASA website Web Publishing Site.) Timelines are approximate; Webb’s team members emphasized that the publishing schedule is flexible, so you don’t need to panic if times and dates change slightly, or if some things happen out of order.
One day after launch, web It will rotate its high-gain antenna toward the ground to further facilitate communications with its processors. A day later, the spacecraft will burn another engine to improve its trajectory toward L2. Three days after launch, the pallet holding Webb’s massive sunvisor — a five-layer structure designed to keep the infrared telescope and its instruments cool — will be lowered.
Each of the shield’s five sheets is the size of a tennis court when fully extended, and is too wide to fit within the payload stream of any missile currently in operation. So the sun visor was launched in a compact configuration and had to be loosened.
This is an incredibly complex process. NASA officials said in the video that the sunvisor’s structure contains 140 release mechanisms, 70 hinged assemblies, 400 pulleys, 90 cables, and eight deployment motors, all of which must function properly so that the five layers are deployed as planned.
The sun visor cap will come off five days after launch, and the booms will extend after one day. Sunshield deployment should be completed eight days after takeoff, at which point team members will begin to shift their focus to optics.
In about 10 days after launch, Webb will extend his 2.4-foot (0.74-meter) secondary mirror, so named because it is the second surface that deep space photons will collide with on their way to the range instruments.
It’s time for your basic 21.3-foot (6.5 m) Webb mirror to shine. That mirror, made up of 18 hexagonal pieces, set off folded, as did the sun visor. Twelve to 13 days after launch, the side mirror «wings» will extend and lock into place, giving the surface its full volume.
At this point, Webb will be in his final form. The massive observatory will reach its destination a little more than two weeks later, burning another engine 29 days after launch to slide into orbit around L2, where a different set of condensation actions will begin.
Two to three months after launch, for example, the team will align the primary mirror segments so that they act as a single light-gathering surface. This would be tedious and time consuming work, as the mirror would have to be perfect with a resolution of 150 nm. (For perspective: the paper is about 100,000 nm.)
«One of our scientists calculated that we’re moving those mirrors more slowly than grass grows because we line them up so precisely,» Jonathan Gardner, deputy chief scientist for the Webb Project, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, told Space. com earlier this month.
While this is happening, the team will also test and calibrate the four Webb science instruments. This will also be a tedious process; The goal is to start regular scientific operations six months after launch.
«We’re looking forward to the end of June,» Gardner said.
Webb’s observation time will be divided into a variety of projects selected by peer review, as is the case with NASA Hubble Space Telescope. Gardner said the first year of Webb’s projects has already been selected, so the new observatory will arrive on Earth when it’s ready to go.
«It’s going to be a wild ride,» Gardner said.
Mike Wall is the author of «AbroadBook (Great Grand Publishing House, 2018; illustrated by Carl Tate), a book on the search for extraterrestrials. Follow him on Twitter Tweet embed. Follow us on Twitter Tweet embed or on Facebook social networking site.