What is the primary function of the detector dewar cooler (DDC)?

• A. To power the missile.
• B. To cool the night vision sight.
• C. To heat the optics.
• D. To recharge the BCU.

Answer: (B)

The detector dewar cooler sharpens the night vision sight by keeping its infrared detector at cryogenic temperatures. Cooling drastically reduces thermal noise and dark current, which are the main things that obscure faint heat signatures in low light. With the detector held cold, the sight can pick up dim targets and produce a clearer, more usable image, improving ranging and target discrimination at night. It isn’t used to power the missile, heat optics, or recharge the battery control unit—its purpose is purely to maintain the detector’s low temperature for optimal imaging.