[1] Following extensive ground testing, the concept was considered promising enough for a flight-test vehicle to be constructed to fully evaluate the new engine.

RARE was constructed using a conventional five-inch (127mm) rocket tube, 10 feet (3.0 m) in length and weighing 153 pounds (69 kg).

Known as CROW, or Creative Research on Weapons, the NAMTC vehicle was intended to demonstrate that a solid-fueled rocket-ramjet was capable of delivering a reasonable payload.

[2] With the ballistic Crow I having proved the propulsion concept sound, follow-up work on a modification of the vehicle to provide guidance was undertaken.

[2] The fourth flight test proved more successful, and Crow was considered to have met the project goals.