Skip to main content

How NASA is testing the James Webb Space Telescope before its launch

Ball Aerospace technician Larkin Carey can be seen carefully removing Webb’s "lens cap" from the Aft Optics Subsystem which has kept the observatory’s sensitive instruments clean, contaminant-free, and protected from stray light throughout the integration and test process.
Here, Ball Aerospace technician Larkin Carey can be seen carefully removing Webb’s “lens cap” from the Aft Optics Subsystem which has kept the observatory’s sensitive instruments clean, contaminant-free, and protected from stray light throughout the integration and test process. NASA/Chris Gunn

The troubled James Webb telescope has suffered a long series of delays but is finally creeping towards its launch, with the recent completion of several milestones in its final round of testing. The NASA observatory will be the successor to the Hubble telescope and once launched into orbit it will study everything from exoplanets to black holes.

The telescope has now reached three milestones in its final round of testing ahead of its planned launch later this year.

Firstly, the telescope’s “lens cap” has been removed. Technically known as the aft optics subsystem cover, this piece protects the instruments during the assembly and preparation stages and prevents any contamination from tainting them. In the image at the top of this page you can see technician Larkin Carey removing the cover so that the rest of the hardware can be folded up for its trip to space.

Secondly, Webb has a tower which telescopes up to 10 feet in length to keep the mirrors and instruments separate from the side of the observatory which faces the sun. This is in order to keep the instruments cool so that fluctuations in heat from the sun don’t affect their readings. The tower was recently deployed for the final time to check it is ready for its eventual deployment in space.

Thirdly, the telescope needs to fold up into a small volume to fit inside the Ariane 5 rocket which will launch it into orbit. This requires a complex system of folding parts, particularly for large items like the tennis-court sized sunshield. The folded sunshield will sit on top of a support called the unitized pallet structure, and now that the lens cap has been removed, the pallet has been folded up ready for launch as well.

These tests were performed at a Northrop Grumman facility in Redondo Beach, California. Once all final tests are complete, the telescope will be folded and stowed for the last time before being shipped to Kourou, French Guiana ready for its launch in November 2021.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
James Webb captures the magnificent Whirlpool Galaxy in two wavelengths
The graceful winding arms of the grand-design spiral galaxy M51 stretch across this image from the NASA/ESA/CSA James Webb Space Telescope. Unlike the menagerie of weird and wonderful spiral galaxies with ragged or disrupted spiral arms, grand-design spiral galaxies boast prominent, well-developed spiral arms like the ones showcased in this image. This galactic portrait is a composite image that integrates data from Webb’s Near-InfraRed Camera (NIRCam) and Mid-InfraRed Instrument (MIRI).

A new image from the James Webb Space Telescope shows a stunning view of spiral galaxy M51, also known as the Whirlpool Galaxy, a galaxy so picturesque it is designated a grand-design spiral galaxy for its prominent, clearly defined spiral arms. The image shows off these arms in their full beauty, reaching out from the galactic center and captured in the infrared wavelengths to show off their structure.

The image was taken using two of Webb's instruments operating in different parts of the infrared: the Near-InfraRed Camera (NIRCam) and the Mid-InfraRed Instrument (MIRI).

Read more
Pollution-tracking NASA satellite shares its first images of air quality
Artist's illustration of TEMPO.

A new NASA satellite designed to monitor pollution from space has shared its first images, showing how it will be able to track air pollution across North America. The TEMPO, or Tropospheric Emissions: Monitoring of Pollution, instrument was launched earlier this year in April and has been observing the Earth from its orbit 22,000 miles above the equator.

Artist's illustration of TEMPO. NASA

Read more
SpaceX calls off Friday’s Crew-7 launch to the space station
Crew-7's Falcon 9 rocket and Dragon spacecraft on the launchpad.

Crew-7's Falcon 9 rocket and Dragon spacecraft on the launchpad. SpaceX

UPDATE: About four hours prior to the targeted launch time, SpaceX posted a message saying it was calling off Friday morning's launch attempt and would now target early Saturday morning instead.

Read more