The guidance unit for the GBU-39 is made up of two sections located where on the bomb body?

• A. To the rear of the warhead and forward of the fins.
• B. In front of the warhead and behind the nose cone.
• C. Inside the tail assembly.
• D. Adjacent to the warhead on either side.

Answer: (A)

The idea being tested is how the guidance electronics are laid out along the bomb’s body to protect them and keep them effective during flight. The two sections of the guidance unit are positioned to maximize protection and sensor performance: one sits behind the warhead and the other sits in front of the tail fins.

Placing a section just behind the warhead helps keep part of the guidance system away from the forward end and its strong aerodynamic forces, while still keeping it near the central portion of the bomb for stable sensing and wiring routes. Positioning the other section ahead of the fins places it where the sensors and antennas have a clearer, less obstructed path to the sky, which improves navigation accuracy and reception. This arrangement also helps maintain proper balance and reduces the impact of tail-end aerodynamics on the guidance electronics.

Choosing other locations, such as inside the tail assembly or adjacent to the warhead on the sides, would place the electronics in less favorable positions for sensor access, signal reception, or protection from flight loads, making this rear-of-warhead and forward-of-fins layout the best fit.