Orbital launches in 1961

SOLRAD (SOLar RADiation) 3 was a solar X-ray satellite, the third in the SOLRAD program. Developed by the United States Navy's Naval Research Laboratory (USNRL), it shared satellite space with and provided cover for the Navy's GRAB 2 (Galactic Radiation And Background), a secret electronic surveillance program.

Explorer 13, (also called S-55A), was a NASA satellite launched as part of the Explorer program on 25 August 1961, at 18:29:44 GMT, from Wallops Flight Facility (WFF), Virginia.

TIROS-3 (or TIROS-C) was a spin-stabilized meteorological satellite. It was the third in a series of Television Infrared Observation Satellites.

OSCAR 1 (Orbiting Satellite Carrying Amateur Radio 1, also known as OSCAR 1) is the first amateur radio satellite launched by Project OSCAR into low Earth orbit. OSCAR I was launched December 12, 1961, by a Thor-DM21 Agena B launcher from Vandenberg Air Force Base, Lompoc, California. The satellite, a rectangular box (30 x 25 x 12 cm) weighing 10 kg., was launched as a secondary payload (ballast) for Corona 9029, also known as Discoverer 36, the eighth and final launch of a KH-3 satellite.

Explorer 10 (also known as Explorer X or P14) was a NASA satellite that investigated Earth's magnetic field and nearby plasma. Launched on 25 March 1961, it was an early mission in the Explorer program and was the first satellite to measure the "shock wave" generated by a solar flare.

Explorer S-45A was a NASA satellite, which was lost in a launch failure in 1961. The satellite was intended to operate in a highly elliptical orbit, from which it was to have provided data on the shape of the ionosphere, and on the Earth's magnetic field. It was part of the Explorer program and would have been designated Explorer 12 had it reached orbit. It was the second of two identical satellites to be launched; the first, Explorer S-45, had also been lost in a launch failure, earlier in the year.

Explorer S-45 was a NASA satellite, which was lost in a launch failure in February 1961. The satellite was intended to operate in a highly elliptical orbit, from which it was to have provided data on the shape of the ionosphere, and on the Earth's magnetic field. It was part of the Explorer program, and would have been designated Explorer 10 had it reached orbit. A second identical satellite, Explorer S-45A, also failed to achieve orbit when it was launched.

LOFTI-1 was an American satellite which was launched in 1961 and operated by the United States Navy and Naval Research Laboratory. It was used to conduct research into the propagation of very low frequency radio signals in the ionosphere, and to investigate if these signals could be received by submarines. A 136.17 MHz transmitter was used for this investigation.

Transit 3B was an American satellite which was launched in 1961 and operated by the United States Navy. It was a replacement for Transit 3A, which was lost in a launch failure the previous year. It carried instruments to demonstrate navigation and timing systems, and study geodesy to support the development of the Transit satellite navigation system.