NF-104A "Rocketdyne AR2-3" Rocket Engine

In addition to the standard J-79 jet engine a Rocketdyne AR2-3 rocket engine was fitted at the base of the vertical fin.
This engine burned a mixture of JP-4 jet fuel and 90% hydrogen peroxide oxidizer solution.
The NF-104 carried enough oxidizer for approximately 100 seconds of rocket engine operation.
The thrust level could be adjusted to maximum or approximately half power by the pilot using an additional throttle lever on the left side of the cockpit.

copyright  Lockheed via Pete Cluckey