Which platform provides high-altitude, long-endurance unmanned ISR capabilities?

• A. RC-135 Rivet Joint
• B. E-6 Mercury
• C. MQ-4 Triton
• D. E-3 AWACS

Answer: (C)

This question is about identifying a platform built for staying on station at great height with long endurance while performing unmanned ISR missions. The MQ-4 Triton fits this role best. It’s a high-altitude, long-endurance unmanned aircraft designed for persistent surveillance and reconnaissance, especially over maritime areas. It commonly operates around 60,000 feet and can remain on station for extended periods—tens of hours in a mission—while carrying sensors for broad-area surveillance, such as radar and electro-optical/infrared payloads, plus signals intelligence capabilities. This combination—unmanned operation, very high altitude, and extended endurance for continuous ISR—defines the platform.

The other options are not unmanned or do not emphasize endurance at high altitude. For example, the RC-135 Rivet Joint is a crewed signals intelligence aircraft, not unmanned. The E-6 Mercury serves as an airborne command post and tanker, again manned. The E-3 AWACS is a crewed aircraft focused on airspace surveillance and command-and-control. None of these match the unmanned, long-endurance, high-altitude ISR profile.