The most powerful telescope ever launched into space is nearing the end of a meticulous assembly process that has kept astronomers on edge for weeks.
Since its launch on Christmas morning, the James Webb Space Telescope has made all the right moves. It is now entering the final stretch of its complex deployment phase.
In these terminal steps, two panels on either side of the telescope assembly of 18 gold-plated hexagonal mirrors, folded during launch, must snap into place to complete Webb’s honeycomb reflector. The 21-foot-wide mirror sends light from the cosmos to a secondary mirror, which then bounces the light off the telescope’s main infrared sensor.
Unfolding the mirrors is a crucial milestone on the road to using the telescope for scientific studies of the Big Bang, exoplanets, black holes, and our solar system. Once complete, NASA considers the telescope to be “fully deployed.”
When will the Webb telescope finish deploying and how can I see it?
The telescope’s deployment phase is expected to end Saturday morning, after the right-side panel of the mirror segment of the remaining three mirrors is secured in place. The left side completed its deployment on Friday, a process that took five and a half hours.
NASA is currently hosting a live stream on NASA TV and YouTube or you can watch it in the embedded video player above. It shows mission managers monitoring the deployment from the flight control room of the Space Telescope Science Institute in Baltimore, the telescope’s central operations center.
At around 10:15 a.m. Eastern time, the mission managers dispatched the first commands to begin deploying the mirrors. Shortly before 10:30, the panel was slowly opened so that the three hexagonal mirrors formed a mosaic with the other 15. Staff clapped before continuing with the next steps to hook the mirrors in place. That process is expected to take at least two hours, concluding around 1:30 pm “I’m excited about that,” said Thomas Zurbuchen, NASA’s chief scientist, of all the telescope mirrors that finally clicked into place. “What an amazing milestone! We see that beautiful pattern in the sky now almost complete. Of course you have to get hooked, but what an amazing milestone. “
But you will not be able to see what is happening in the telescope.
Why are there no cameras on the telescope?
Rockets and some spacecraft have built-in cameras so engineers on Earth can monitor their behavior in space. So one would expect engineers to pack cameras aboard the James Webb Space Telescope, the most expensive and technically complex observatory ever launched into space, with 344 “single points of failure.”
Think again.
There are no surveillance cameras on the telescope. Instead, engineers rely on switches, sensors, and motors to track their status during deployment.
NASA dropped the idea of including surveillance cameras in Webb due to technical complexities and risks. The telescope’s novel size and shape, with one side of its hood deflecting enormous amounts of heat and sunlight and the other side, which has many instruments, basking in the freezing darkness, would require several custom-made cameras. Cables and mounts for those cameras would add weight and risk to an already heavy telescope, the agency explained in a blog post.
“It’s not as simple as adding a doorbell camera or even a rocket camera,” said Paul Geithner, NASA’s deputy project manager for the technical side of the Webb program.
What has happened to the telescope so far?
Since Webb’s launch, engineers have completed more than a dozen major steps in the deployment phase to bring the telescope to its final form, involving hundreds of moving parts such as switches, motors, pulleys and cables. The process began less than 30 minutes after launch last month, when Webb’s solar array was deployed, the only step captured on video when the telescope was separated into space with its rocket, which had an onboard camera.
The telescope has passed a number of milestones since then, doing well to quell astronomers’ anxiety and quell fears that a structure as intricate as Webb was destined to bump into obstacles throughout its million-mile journey to the place in space where it will remain. The telescope powered up, deployed antennas, mechanically deployed various limbs, and, in the most technically complex milestone, delicately stretched five layers of tennis-court-sized plastic sheet designed to shield the telescope’s ultra-sensitive camera sensors from heat. of the sun.
Why is the telescope so important to scientists?
The Webb Telescope was designed to probe a crucial stretch of early cosmic history, known to astronomers as the dark ages.
Cosmologists assume that the first stars appeared when the universe was only about 100 million years old. (Today it is 13.8 billion years old). The oldest and most distant galaxy seen by astronomers, using the Hubble Space Telescope, dates back to when the universe was oldest, 400 million years after the Big Bang. What happened during those 300 million years in between when the universe took a luminous flight, how the Big Bang became a sky full of constellations and life, is a mystery.
The telescope will also help astronomers better study supermassive black holes at the center of galaxies and planets that orbit other stars in our galaxy.
To achieve these scientific observations, the Webb telescope relies on a 6.5-meter diameter primary mirror, compared to Hubble’s mirror, which is 2.4 meters. That gives you about seven times more light-gathering ability, and therefore the ability to see more in the past.
Another crucial difference is that it is equipped with cameras and other instruments sensitive to infrared radiation or “heat”. The expansion of the universe causes light that would normally be in visible wavelengths to shift to longer infrared wavelengths, normally invisible to human eyes.
Engineers had to invent 10 new technologies along the way to make the telescope more sensitive than Hubble. Overly optimistic schedule projections, occasional development crashes, and disorganized cost reporting dragged the schedule through 2021 and brought the total cost to $ 10 billion.
Turn your phone into a personal planetarium.
To understand the powers of observation of the James Webb Space Telescope and how it will help astronomers in their research, try these two augmented reality experiences in your own space with an Instagram-connected smartphone.
The first will show you where in space and time Webb will look with a three-dimensional map of the observable universe. It maps out some of the spacecraft’s earliest targets, including potentially Earth-like exoplanets and the earliest known galaxies. Try it here on Instagram.
The second augmented reality experience shows how Webb will get a visual boost thanks to the power of gravitational lenses.
Place a virtual black hole in your space and observe how it behaves like a magnifying glass in your environment. This same technique will help astronomers study the early universe. Try it here on Instagram.
Noah pisner contributed to reporting.