NASA's James Webb Space Telescope, artist's conception, from the environment of space.

After years of preparation, numerous tests, and an unfortunate number of setbacks, NASA’s James Webb … [+] Space Telescope is fully built and assembled. As of October 6, 2020, it has completed its full suite of environmental tests: the last challenging, and potentially blocking, milestone keeping us from a successful launch.

Northrop Grumman

Despite numerous delays, funding crises, and technical challenges, NASA’s James Webb Space Telescope is almost ready.

The science instruments aboard the ISIM module being lowered and installed onto JWST.

The science instruments aboard the ISIM module being lowered and installed into the main assembly of … [+] JWST in 2016. These instruments have been complete for nearly a decade, and have passed all of their rigorous tests. They, along with the rest of James Webb, are ready for launch.

NASA/Chris Gunn

Every single component is fully built, assembled, and integrated.

Mirror test in the clean room of JWST in NASA's Goddard Space Flight Center.

Engineers conduct a “Center of Curvature” test on NASA’s James Webb Space Telescope in the clean … [+] room at NASA’s Goddard Space Flight Center, Greenbelt, Maryland. This test helped ensure there would be no Hubble-like problems on JWST.

NASA / Chris Gunn

Rigorous pre-launch testing can maximize our chances for Webb’s success.

Comprehensive systems evaluation of NASA's James Webb space Telescope.

Following the complete assembly of NASA’s James Webb Space Telescope, testing teams performed a … [+] comprehensive systems evaluation which allowed them to confidently assess Webb’s software and electronic performance as a single fully connected vehicle.

NASA/Chris Gunn

Recommended For You

The stowed telescope must survive harsh launch conditions without sustaining damage.

NASA's James Webb Space Telescope, folded into its pre-launch configuration.

NASA’s James Webb Space Telescope was folded into its pre-launch configuration and transported to a … [+] series of specially-designed chambers for acoustic and sine-vibration testing. After weeks of these tests, Webb emerged fully intact and undamaged.

NASA/Chris Gunn

From its spaceborne environment, all components must then properly deploy.

The primary mirror segments must unfold, aligning to within 20 nanometer tolerance.

The 18 segments of James Webb in the laboratory.

The 18 segments of James Webb in the laboratory, after completed assembly and all coatings have been … [+] applied. From the zero-gravity environment of space, these individual segments must form a perfect single plane to within a 20 nanometer tolerance.

NASA/Chris Gunn

All 5 sunshield layers must unfurl without catching, ripping, or tearing.

The JWST sunshield, prototyped and tensioned in the clean room in Greenbelt, Maryland.

This James Webb Space Telescope sunshield prototype is a 1/3rd scale model of the real thing, which … [+] will be the largest device of its type when James Webb is launched in 2021. This passive cooling system can cool the telescope down below 77 K: the threshold at which nitrogen gas becomes liquid nitrogen.

Alex Evers/Northrop Grumman

Earlier testing exposed vulnerabilities that could arise during launch-and-deployment.

The James Webb Space Telescope in the NASA clean room, prior to transport for testing.

During a 2018 environmental test of the spacecraft element, some screws and washers came off of the … [+] bus and sunshield: a flaw that required correction. As of the last and final round of vibration and acoustic testing, this problem appears to have been successfully corrected, while no other comparable ones have arisen.

Northrop Grumman

Subsequent structural corrections and improvements were then implemented.

NASA's James Webb Space Telescope during a ″lights out″ inspection.

After a vibration and acoustic test is completed, a “lights out” inspection occurs, as any possible … [+] contamination is easier to find in the dark. NASA’s James Webb Space Telescope has been subject to a number of these tests over the past few years, with the telescope passing the final test, concluded in October of 2020, in every way.

NASA / Chris Gunn

On October 6, 2020, NASA and Northrop Grumman successfully completed Webb’s final environmental stress-test.

NASA’s James Webb Space Telescope sits inside Chamber A at NASA’s Johnson Space Center.

NASA’s James Webb Space Telescope sits inside Chamber A at NASA’s Johnson Space Center in Houston … [+] after having completed its cryogenic testing on Nov. 18, 2017. This marked the telescope’s final cryogenic testing, and it ensured the observatory is ready for the frigid, airless environment of space. Other tests, like vibration testing, did not go according to plan.

NASA/Chris Gunn

Over several weeks, Webb underwent rigorous trials, experiencing harsher conditions than actual launches.

Vibration testing of spacecraft, such as NASA's James Webb, is a necessity.

Vibration testing of spacecraft, such as NASA’s James Webb, is a necessity to ensure that the … [+] spacecraft and all of its components can survive the launch process intact and fully functional. Crewed and uncrewed missions alike must survive this testing, which has been applied to Webb in a number of phases.

NASA / Chris Gunn

It survived high-frequency acoustic pressures, including sounds surpassing 140 decibels.

Animation of the James Webb Space Telescope atop the environmental testing pad.

Animation of the James Webb Space Telescope atop the pad on which it undergoes a portion of its … [+] environmental tests that focus on acoustics and vibrations. These tests are necessary for ensuring that Webb survives its launch and deploys as required.

NASA / Northrop Grumman

Sine-vibration testing shook the spacecraft intensely, exceeding vibrational stresses occurring inside a launching rocket.

Animation of a rocket launch, which is far greater in intensity than a rock concert.

A rocket launch experiences sonic intensity and vibrations that are 100 times greater in intensity … [+] and 20 decibels greater in loudness than the loudest seats of all at a rock concert. To simulate a rocket launch, both acoustic and vibrational tests are required.

NASA / ArianeSpace

Unlike prior tests, every single component survived, retaining optimal functioning.

James Webb's 5-layer sunshield unfurling and experiencing tensioning during a test.

The process of unfurling and tensioning the 5-layer sunshield is one of only a very few tests … [+] remaining for NASA’s James Webb Space Telescope to be fully launch-ready.

NASA / James Webb Space Telescope team

Only sunshield and mirror deployment testing, plus a final systems evaluation, remain as pre-launch milestones.

Completion of the James Webb Space Telescope primary mirror's deployment sequence.

One of the last tests that will be performed on NASA’s James Webb is a final check of the mirror … [+] deployment sequence in full. With all environmental stress testing now out of the way, these last checks will hopefully be routine, paving the way for a successful 2021 launch.

NASA / James Webb Space Telescope team

Webb, stowed onboard an Ariane 5, will launch October 2021 from French Guyana.

A 2017 launch of an Ariane 5 rocket, previewing the launch of NASA's James Webb.

This 2017 launch of an Ariane 5 rocket mirrors the launch vehicle of NASA’s James Webb Space … [+] Telescope. The Ariane 5 had a string of more than 80 consecutive launch successes before a partial failure a few years ago. It is one of the most reliable launch vehicles in space history.


With environmental testing now complete, the Universe awaits.

NASA's James Webb space telescope will surpass the distance limits of Hubble.

As we’re exploring more and more of the Universe, we’re able to look farther away in space, which … [+] equates to farther back in time. The James Webb Space Telescope will take us to depths, directly, that our present-day observing facilities cannot match, with Webb’s infrared eyes revealing the ultra-distant starlight that Hubble cannot hope to see.


Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like

Trump signs an executive order allowing mining the Moon and asteroids – Universe Today

In 2015, the Obama administration signed the U.S. Commercial Space Launch Competitiveness…

Google just released 1,000 new images of the most gorgeous landscapes in Google Earth View

Google has shared bird’s-eye-view images of some of Earth’s most stunning landscapes…