SAMOS 2 was launched from the Pacific Missile Range into a near-circular polar orbit to determine the capability for making observations of space, the atmosphere, and the nature of the globe from satellites. The 4100-lb spacecraft was a cylinder 22 ft long and 5 ft in diameter, and it comprised the entire Agena A second stage. Included in the instrumentation were photographic and associated test equipment, acoustical micrometeorite detection apparatus, a plasma probe, and an electric field meter. The computer on board was digital-to-analog. Telemetry, tracking, and command equipment completed the payload. Details about the satellite's transmitter were not announced. A conical nose cap detached from the satellite casing and remained in orbit. The expected lifetime of the satellite was 15 years, and the expected lifetime of the nose cap was 12 years.