Webb’s Optical Telescope element/Integrated Science module (OTIS) was placed in NASA’s Johnson Space Center’s historic Chamber A on June 20, 2017, to prepare for its final three months of testing in a cryogenic vacuum that mimics temperatures in space. Chamber A simulates an environment where the telescope will experience extreme cold–around 37 kelvins (minus 236 degrees Celsius or minus 393 degrees Fahrenheit).
