One of the most important tasks involved with having telescopes in space is keeping them at the correct and constant temperature. It's not just because telescopes like Chandra like to be comfortable â€“ it's crucial in making the instruments perform as they should and return accurate science.
For Chandra, controlling the temperature on board is mainly done using thermal coatings and multilayer insulation blankets that were built into the spacecraft. There are also computer-controlled electrical heaters onboard that controllers on the ground can use in certain cases. For example, the coatings and the blankets sometimes arenâ€™t enough to maintain sensitive items such as the mirror assembly at the preferred temperature of a nearly constant 70 degrees Fahrenheit. The focal plane of the scientific instruments such as ACIS is kept much cooler, at a temperature of about -150 degrees Fahrenheit.