In the Gulf War, F-15Es flew mainly at night to hit Scud missile launchers and artillery sites.
The aircraft maintains the air-to-air combat ability of the main F-15 fighter as the pilot can detect and fire at other aircraft. But the major modification is that the weapons officer, sitting behind, is concentrating on lining up the next target on the ground.
F15E Strike Eagles are equipped with the LANTIRN navigation and targeting system which aims to improve the accuracy of attacks by using infrared or laser-guided bombs.
The infrared part of the navigation system projects a green image of the terrain on to a screen in front of the pilot.
The image is grainy, but good enough to be able to fly at very low level at night, although rain, fog, or smoke adversely affect it.
Its terrain-following radar can be linked to the aircraft's autopilot - so the plane itself can follow the contours of the landscape at a height of just 100 ft (30 m).
The US Air Force lists an "active force" of nearly 400 F-15s.