Webb telescopeNorthrop Grumman has successfully completed the testing of preflight template sunshield layers installed on NASA’s James Webb Space Telescope.

The company tested the tennis-court-sized sunshield’s template layer five, which keeps the telescope cool and further assists in imaging the faint infrared light.

During the test, the engineers used the laser tracking instrument and a laser radar unit to measure the 3D shape of the test layer in two diverse orientations, which include face-up and rotated 180° to face-down.

The obtained measurements were then compared with an analytical model, which predicted the behaviour of the ultra-thin material in close to zero gravity environments.

Northrop Grumman Aerospace Systems Webb sunshield manager Jim Flynn said: "The as-built and measured membrane was within .36in root-mean-squared of the 3D shape the model predicted, over an area as large as a tennis court, which is remarkable."

The sunshield membrane layers, made of Kapton, will cool the telescope to a temperature of -375°F and will avoid the observatory’s own heat from blinding its infrared sensing instruments.

Northrop Grumman said that the template or test layers were being used to validate processes and performance prior to the fabrication of the flight sunshield layers.

“The as-built and measured membrane was within .36in root-mean-squared of the 3D shape the model predicted, over an area as large as a tennis court, which is remarkable.”

The company has also successfully completed qualification testing of six gearmotors or actuators, which allow the sunshield layers to open up during Webb’s travel, further demonstrating engineering design and allows it to proceed with the production of flight hardware.

During the test, gearmotors were exposed to tough tests to replicate the effects of severe temperature variations, vibrations, operating loads and performance all through the unit’s life.

Successor to the Hubble Space Telescope, the James Webb Space Telescope is a joint project of NASA, the European Space Agency (ESA) and the Canadian Space Agency and is claimed to be the most powerful space telescope ever built.

The Webb telescope will allow monitoring the most distant objects in the universe, offer images of the first galaxies formed and examine planets around distant stars.


Image: Webb will travel nearly one million miles from Earth to reach its orbit. Photo: courtesy of ESA.