Which of the following is NOT among the listed environmental tests?

• A. Radiation exposure test
• B. Thermal cycling
• C. Vacuum
• D. Vibration

Answer: (A)

Environmental testing in space hardware focuses on simulating the physical conditions the system will experience in its surroundings. The three tests listed—thermal cycling, vacuum, and vibration—are classic examples of these environmental conditions: they push the hardware through temperature swings, operate in a near-vacuum to check seals and outgassing, and reproduce the shakes and loads of launch and handling.

A radiation exposure test, while important for understanding how electronics and materials tolerate ionizing radiation, is not part of the typical environmental-test group shown here. It’s a separate category that assesses radiation hardness and its effects, rather than the ambient physical conditions like temperature, pressure, or mechanical loads. Therefore, radiation exposure is not among the listed environmental tests.