NASA's "Chamber A" thermal vacuum testing chamber has now been upgraded and remodeled to accommodate the testing of the James Webb Space Telescope.

Chamber A, the largest high-vacuum, cryogenic-optical test chamber in the world, was made famous for testing the space capsules for NASA's Apollo mission, with and without the mission crew. The chamber is 55 feet (16.8 meters) in diameter by 90 feet (27.4 meters) tall. The door weighs 40 tons and is opened and closed hydraulically.

For three years, NASA Johnson engineers have been building and remodeling the chamber interior for the temperature needed to test the Webb telescope. Testing will confirm that the telescope and science instrument systems perform properly together in the cold temperatures of space. Additional test support equipment includes mass spectrometers, infrared cameras, and television cameras so engineers can keep an eye on the Webb while it's being tested.

"Some of the things we've done is upgraded our helium system, our liquid nitrogen system, and air flow management," said Virginia Rivas-Yancy, project manager, Air Flow Management System at NASA's Johnson Space Center. Temperatures in Chamber A can now drop farther than ever — down to -439.9 Fahrenheit (-262.1 degrees Celsius or 11 degrees Kelvin).

A very large clean room is also being prepared near Chamber A where the observatory will be prepped for testing. The test itself will take 90 days. The first 30 days will consist of cooling the chamber down. The next few weeks will include tests on the telescopes's operating systems, and the remainder of the time will be spent warming up the chamber to room temperature.


Also: Learn about the Cryogenic Test Laboratory (CTL) at Kennedy Space Center.