The Martin X-23 PRIME (Precision Recovery Including Maneuvering Entry) was a small uncrewed lifting body re-entry vehicle tested by the United States Air Force in the late 1960s. PRIME 3 mission was flown on 19 April 1967 and simulated reentry from low-earth orbit with a 1143 km cross-range. This time, all systems performed perfectly, and the X-23 was successfully recovered.
SuborbitalThe Transit-O series of satellites that closely followed the design of Transit 5C-1 were also called “Oscars” (Oscar is the phonetic alphabet for “O”, i. e., operational). They were also called NNS (Navy Navigation Satellite) or shortened NavSat.
Polar OrbitATS 2 (Applications Technology Satellite) was a medium altitude, gravity-gradient-stabilized spacecraft designed to test new concepts in spacecraft design, propulsion, and stabilization, take high-quality cloudcover pictures, provide in situ measurements of the aerospace environment, and test improved communication systems.
Medium Earth Orbit