NASA has announced that it is currently testing an element of the sunshield that will be used to protect the James Webb Space Telescope's mirrors and instruments when it embarks on its mission to observe the most distant objects in the universe.

The sunshield will be made up of five tennis court-sized layers that allow the James Webb telescope to cool to its cryogenic operating temperature of minus 387.7 degrees Fahrenheit (40 Kelvin), according to NASA.

The James Webb telescope is the world's next-generation space observatory and it is successor to the Hubble Space Telescope.

Considered the most powerful space telescope ever built, the James Webb telescope will provide images of the very first galaxies ever formed. It will also explore planets around distant stars.

The James Webb telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

Testing of the sunshield began early this month at ManTech International Corp.'s Nexolve facility in Huntsville, Ala. Researchers are using flight-like material for the sunshield, a full-scale test frame and hardware attachments.

NASA said the test sunshield layer consists of Kapton, which is a very thin, high-performance plastic with a reflective metallic coating, similar to a Mylar balloon.

Each sunshield layer is said to be less than half the thickness of a sheet of paper, and it is stitched together like a quilt from more than 52 individual pieces because manufacturers don't make Kapton sheets as big as a tennis court, NASA said.

The tests are scheduled to be done in two weeks.

The conclusion of testing on this full size layer will be the final step of the sunshield's development program and provides the confidence and experience to manufacture the five flight layers, said Keith Parrish, Webb Sunshield manager at NASA's Goddard Space Flight Center in Greenbelt, Md., in a press statement.

During testing, engineers will use a high-precision laser radar to measure the layer every few inches at room temperature and pressure, thus creating a 3D map of the material surface, which is curved in multiple directions.

The map will then be compared to computer models to see if the material behaved as predicted. Engineers will also see whether critical clearances with adjacent hardware are achieved.

The test will be conducted on all five layers to give engineers a precise idea of how the entire sunshield will behave once in orbit.

Last year, a one-third-scale model of the sunshield was tested in a chamber that simulated the extreme temperatures it will experience in space. The test confirmed the sunshield will allow the telescope to cool to its operating temperature.

After the full-size sunshield layers complete testing and model analysis, they will be sent to Northrop Grumman in Redondo Beach Calif., where engineers will verify the process of how the layers will unfurl in space.

From there the sunshield layers will be folded, much like a parachute, so they can be safely stowed for launch, NASA said.