Skip to main content

James Webb telescope undergoes vacuum testing, finally moving toward launch

Technicians and engineers needed to take special precautions when preparing and transporting Webb’s spacecraft element for entry into Northrop Grumman’s environmental testing chambers. Northrop Grumman

The long-delayed James Webb telescope is finally moving toward completion. The telescope recently passed a key round of testing ahead of its planned launch in 2021.

The vehicle that will launch the telescope into space went through vacuum testing, in which the craft is exposed to a simulation of the space environment. This involves the use of a thermal vacuum chamber into which the spacecraft is placed. Engineers can then test its resilience to the extreme temperatures of launch and space, ranging from minus 235 degrees Fahrenheit (minus 148 degrees Celsius) to 215 degrees Fahrenheit (102 degrees Celsius)

The telescope itself went through vacuum testing last year at NASA’s Johnson Space Center. But now the other half of the project, the spacecraft element, has passed its testing at Northrop Grumman as well.

“The teams from Northrop Grumman and NASA Goddard Space Flight Center are to be commended for a successful spacecraft thermal vacuum test, dedicating long hours to get where we are now,” Jeanne Davis, program manager for the James Webb Space Telescope Program, said in a statement. “This incredible accomplishment paves the way for the next major milestone, which is to integrate the telescope and the spacecraft elements.”

The spacecraft element consists of a “bus,” which is the part that flies the telescope into place, and the unique sunshield that will protect the telescope’s delicate circuitry from the heat of the Sun. The sunshield is made up of five layers and spans the size of a tennis court, and is designed to ensure the telescope instruments are kept at the low temperatures required for successful operation.

Now that both parts of the craft have gone through vacuum testing, the next challenge is for the engineers to join the two together. Then a final round of testing can begin, making sure that every part is ready for its big launch. When it launches, it will be the world’s most powerful telescope and will be the successor to the beloved Hubble telescope. It should be able to collect images at a higher resolution and sensitivity, observing some of the most distant objects in the universe.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
James Webb begins aligning 3 of its instruments
This artist’s conception shows the fully unfolded James Webb Space Telescope in space.

The James Webb Space Telescope recently hit a big milestone when engineers completed the alignment of its mirrors. But there is still a lot to do before the telescope is ready to begin science operations this summer. With the mirrors aligned with Webb's instruments, NIRCam, now the team needs to work on aligning the other three instruments, and it recently began to do that with a process called multi-instrument multi-field (MIMF) alignment.

The six-week MIMF alignment process will align the three instruments plus Webb's guidance system, called the Fine Guidance Sensor (FGS). This process is necessary to allow Webb to switch seamlessly between its different instruments. All the cameras observe at the same time, so if researchers want to look at a particular target like a star using different instruments, the telescope needs to be repointed to move the target into the field of view of the new instrument.

Read more
Image of James Webb snapped by the Gaia observatory
Gaia’s sky mapper image showing the James Webb Space Telescope. The reddish colour is artificial, chosen just for illustrative reasons. The frame shows a few relatively bright stars, several faint stars, a few disturbances – and a spacecraft. It is marked by the green arrow.

The James Webb Space Telescope doesn't orbit the Earth as the Hubble Space Telescope does. Instead, it orbits the sun in a position called the second Sun-Earth Lagrange point, or L2, where it can remain in a stable orbit with one side pointing toward the sun and the other side remaining in the shade. Webb isn't alone in this L2 orbit though -- other spacecraft are there too, including the European Space Agency (ESA)'s Gaia observatory.

That meant there was an opportunity for Gaia, which arrived at L2 in 2014, to capture an image of its new companion. Last month, the two spacecraft were 600,000 miles apart and Gaia was able to snap a picture of Webb. As Webb is edge-on from the view of Gaia, it only reflects a small amount of light and so it appears as a small speck of light in the image.

Read more
James Webb Space Telescope team delivers best possible news
James Webb Space Telescope illustration.

Work to align the James Webb Space Telescope’s enormous mirror has gone so well that the mission team believes its optical performance will be able to “meet or exceed the science goals the observatory was built to achieve.”

NASA’s Webb Reaches Alignment Milestone, Optics Working Successfully

Read more