Work resumes on James Webb Space Telescope after COVID interruption

Work resumes on James Webb Space Telescope after COVID interruption
By Astronomy Now

Northrop Grumman engineers monitor a test of the mechanism that will be used to slightly separate the James Webb Space Telescope’s mirrors and instruments from the heat generated by the spacecraft’s electronics and propulsion systems after the observatory reaches orbit. Image: Northrop Grumman

After weeks of downtime in the wake of the coronavirus, engineers have resumed near-normal work readying the James Webb Space Telescope for launch. Most recently, the deployable tower assembly, a telescoping structure will be used to separate JWST’s mirrors and instruments from hotter sections of the spacecraft, was extended in a key test at Northrop Grumman’s California manufacturing facility.

NASA managers are assessing the impact of the COVID-19 work stoppage on JWST’s eventual launch date. While officially scheduled for liftoff from Kourou, French Guiana, atop an Ariane 5 rocket, in March, the launch is expected to slip. The question is, by how much?

“The NASA/Northrop Grumman team recently resumed near-full operations,” the U.S. space agency said in a blog post. “NASA is evaluating potential impacts on the March 2021 launch date, and will continually assess the schedule and adjust decisions as the situation unfolds.”

The deployable tower assembly, or DTA, is a critical component that will enable the telescope to operate at the ultra-low temperatures required for its planned infrared observations of the early universe.

Resembling a large black pipe, the DTA is made out of graphite-epoxy composite material, stretching 3 metres (10 feet) when full extended. To fit inside the Ariane 5’s 5.4-metre (17.8-foot) nose fairing, the James Webb however, the DTA will extend, separating the telescope’s mirrors and instruments from the spacecraft bus housing its electronics and propulsion systems.

By opening a gap between the two sections, the DTA will help JWST’s active and passive cooling systems to down to their operating temperature of around 50 degrees above absolute zero.

“The deployable tower assembly worked beautifully during the test,” said Alphonso Stewart, lead engineer of the observatory’s deployment systems. “It performed exactly as predicted. This was the first time that this part of Webb was tested in its flight-like configuration to the highest level of fidelity we possibly could.”

June 10, 2020 at 08:30PM
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