When the next-generation space telescope was being designed, engineers had to ensure there was a place large enough to test it, considering it’s as big as a tennis court. That honor fell upon the famous “Chamber A” in the thermal-vacuum test facility at NASA’s Johnson Space Center in Houston, Texas.

NASA’s “Chamber A” thermal vacuum testing chamber famous for being used during Apollo missions has now been upgraded and remodeled to accommodate testing the James Webb Space Telescope.

Chamber A is now the largest high-vacuum, cryogenic-optical test chamber in the world, and made famous for testing the space capsules for NASA’s Apollo mission, with and without the mission crew.

For three years, NASA Johnson engineers have been building and remodeling the chamber interior for the temperature needed to test the Webb. Testing will confirm the telescope and science instrument systems will 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.