Defense Support Program (DSP) is primarily used for which function?

• A. Communications (Protected SATCOM)
• B. Space Surveillance
• C. Missile Warning
• D. Meteorology

Answer: (C)

Defense Support Program is designed to provide missile warning by detecting the infrared signature of rocket plumes during launch. Its sensors pick up the intense heat from exhaust, which stands out against space and the Earth background, allowing quick detection and localization to alert defense forces. This early warning gives command centers and interceptors minutes to react, which is the critical capability DSP is built to deliver. It’s not intended for communications, space surveillance, or meteorology, which are handled by other systems and instruments.