To prepare spacecraft for their difficult interplanetary journey where they will encounter extremes of vibration, pressure, temperature, radiation and shock, engineers at JPL put them through a series of tests called environmental testing . These tests help JPL engineers determine if spacecraft components will be robust enough to handle the extremes of space.
Engineers check for anomalies such as cold welding or performance irregularities in the spacecraft.
To detect these flaws, the two most common environmental tests are vibration testing and thermal vacuum exposure. The first test simulates the shaking and vibration frequencies a spacecraft will experience during the launch phase. During this test engineers make sure that the spacecraft and instruments do not have loose fittings and can survive a range of vibration modes. Tests are designed for specific launch vehicles, since each launch vehicle has its own set of distinct vibration modes. The second test simulates exposure to the environment of space.