James Webb Telescope Passes Final Thermal Vacuum Test

Once in orbit the telescope will help find new planets.
Jessica Miley

It has been a big week of testing for NASA. Not only did the service capsule from the spacecraft Orion go through a battery of acoustic tests, but the James Webb Space Telescope also passed its final thermal vacuum test. The telescope which is set to be launched in 2021 had already graduated from An initial vacuum test, but it has now passed the “spacecraft element” as well.


The test sees the telescope locked inside a vacuum chamber and then subjected to the conditions of space to ensure all the electronics of the instrument will work. The tests include pushing the temperature up to a roasting 215 degrees Fahrenheit then down to minus 235 degrees Fahrenheit.

NASA and Team Proud of Achievements

“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,” said Jeanne Davis, program manager for the James Webb Space Telescope Program, 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 telescope is not quite assembled fully assembled, once that gets done it will undergo another round of test before preparing for its launch. The telescope has been earmarked for a series of exciting investigations that will be fully decided once the capabilities of the telescope are understood some time after it has settled into its orbit.

New Planets to Find

One task it will definitely be doing is survey the hundreds of exoplanets that scientists have identified but never actually seen. The planets presence is inferred by their shadow crossing the sun but the Webb telescope should be able to provide more concrete evidence.

“Most of the planets that we have detected so far are roughly 10,000 to 1 million times fainter than their host star,” explained Sasha Hinkley of the University of Exeter. Hinkley is the principal investigator on one of Webb’s first observation programs to study exoplanets and exoplanetary systems. “There is, no doubt, a population of planets that are fainter than that, that have higher contrast ratios, and are possibly farther out from their stars,” Hinkley said.

“With Webb, we will be able to see planets that are more like 10 million, or optimistically, 100 million times fainter.” The telescope is also expected to be able to see planets that we don’t even know exist yet.

“Our program is looking at young, newly formed planets and the systems they inhabit,” explained co-principal investigator Beth Biller of the University of Edinburgh. “Webb is going to allow us to do this in much more detail and at wavelengths we’ve never explored before. So it’s going to be vital for understanding how these objects form, and what these systems are like.”