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.
Transcript
00:00:00 music music music Right now, we are at the Johnson Space Center in Houston, Texas, standing inside the space environment simulation laboratory in front of Chamber A Chamber A actually the largest thermal vacuum chamber in the world It has a 40 foot diameter door which weighs 40 tons The door is Hydraulically operated and it's 3 tons and it's perfectly balanced, it's so balanced that 2 people can push against the door and move it. Chamber A is currently undergoing
00:00:41 upgrades so that it can house the largest satellite, the James Webb Space Telelscope and its testing for the space environment So for the last 3 years we've been rebuilding, remodeling the interior of the chamber so that it's acceptable for the cleanliness and the temperature that James Webb needs. Some of the things we've done, is we've upgraded our helium system, we've upgraded our liquid nitrogen system. As well as updating our air flow management system. With all these upgrades put together, we can now reach temperatures that no one has ever really been able to reach before. We're actually going to 11 Kelvin, which is 11 degrees Celsius essencially
00:01:21 above Absolute Zero, so the absolute coldest we can get to. That's possible, not even really possible. What we get out of a thermal vacuum chamber test is that we can evaluate whether or not the spacecraft all its systems perform like they're supposed to perform once they're out in space. All the air inside the chamber right now at ambient temperature weighs about as much as 12 and a half Volkswagen Beatles, so about 25 tons so by tie you remove all the air and all the molecules out, all the mass inside the chamber is equivalent of about half a staple. That's very rough, but you
00:02:02 kind of put it in perspective of what we are doing. [sound of door closing] Chamber a was originally built as a simulation for the Apollo missions to test the Apollo capsule Back for Apollo, the chamber had to be ready to have people put into the chamber inside their vehicle, so it was man-rated. It still is man-rated, but we obviously don't need to put people on the telescope, so that's not much of a concern for us anymore what is a concern is that the telescope has have a very clean environment because it's an optical telescope. Actually, right where I'm standing right now,
00:02:42 several feet back and all the way to the chamber and all the way to both sides of the highbay we're going to be installing a very large clean room that will allow engineers and technicians to work on the satellite as they are prepping it to go into the chamber. During the final flight test of James Webb it will be in the chamber for, we're anticipating 90 days The first, roughly 30 of those days we will not be doing anything more than cooling it down because its got to radiate all its heat out to those cold shroud walls, it will take a long time for it to drift down to its eventual
00:03:23 operating temperature. Then for the next period of weeks they will be running tests on the instrumentation systems and at the end it will take us about another two and a half, three weeks to warm it back up so we bring it back out into the Houston humidity Chamber is now the most capable thermal vacuum chamber on the planet music music beep beep beep
