Photo courtesy of NASA. Click to enlarge.
The environment outside Earth's atmosphere is unforgiving—humans could last maybe 3 minutes in the vacuum of space before expiring. (Luckily, they'd only be conscious for about 15 seconds of that.) But space isn't just tough for humans; it's also pretty rough on the equipment astronauts use there, so everything bound for space must be vigorously tested. Vacuum Chamber 5 (VF-5), located at NASA’s Glenn Research Center in Cleveland, is one place where electric propulsion systems are put to the test.
Though there are many vacuum chambers at Glenn Research Center (including the world's largest), VF-5 does the best job of re-creating a space environment thanks to "the highest pumping speed of any electric propulsion test facility in the world," according to NASA.
The facility is equipped with cryogenic panels, located at the top and back of the chamber, which contain a helium-cooled panel that can reach a chilly -440 degrees Fahrenheit (absolute zero is -459.67 degrees Fahrenheit). As NASA explains, "The extreme cold of this panel freezes any air left in the chamber and quickly freezes the thruster exhaust, allowing the chamber to maintain a high vacuum environment. The outer chevrons are cooled with liquid nitrogen to shield the cryogenic panels from the room temperature surfaces of the tank." It's in these conditions that NASA then tests electric propulsion and power systems crucial to space missions, such as hall thrusters.
The super-cold conditions also help capture the xenon propellant used in the testing, which freezes to ice. NASA collects and reuses the pricey propellant.
VF-5 is currently being used to test Solar Electric Propulsion technology, which will help take future astronauts to Mars and beyond.