The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the inner Solar System - visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations.
Mariner 2, an American space probe to Venus, was the first robotic space probe to report successfully from a planetary encounter. The first successful spacecraft in the NASA Mariner program, it was a simplified version of the Block I spacecraft of the Ranger program and an exact copy of Mariner 1. The missions of the Mariner 1 and 2 spacecraft are sometimes known as the Mariner R missions. Original plans called for the probes to be launched on the Atlas-Centaur, but serious developmental problems with that vehicle forced a switch to the much smaller Agena B second stage. As such, the design of the Mariner R vehicles was greatly simplified. Far less instrumentation was carried than on the Soviet Venera probes of this period—for example, forgoing a TV camera—as the Atlas-Agena B had only half as much lift capacity as the Soviet 8K78 booster. The Mariner 2 spacecraft was launched from Cape Canaveral on August 27, 1962, and passed as close as 34,773 kilometers (21,607 mi) to Venus on December 14, 1962.
Mariner 1, built to conduct the first American planetary flyby of Venus, was the first spacecraft of NASA's interplanetary Mariner program. Developed by Jet Propulsion Laboratory, and originally planned to be a purpose-built probe launched summer 1962, Mariner 1's design was changed when the Centaur proved unavailable at that early date. Mariner 1, were then adapted from the lighter Ranger lunar spacecraft. Mariner 1 carried a suite of experiments to determine the temperature of Venus as well to measure magnetic fields and charged particles near the planet and in interplanetary space.
Ranger 1 was a prototype spacecraft launched as part of the Ranger program of uncrewed space missions. Its primary mission was to test the performance of those functions and parts necessary for carrying out subsequent lunar and planetary missions; a secondary objective was to study the nature of particles and fields in the space environment. Due to a launch vehicle malfunction, the spacecraft could reach only Low Earth orbit, rather than the high Earth orbit that had been planned, and was only able to complete part of its mission.
Ranger 2 was a flight test of the Ranger spacecraft system of the NASA Ranger program designed for future lunar and interplanetary missions. Ranger 2 was designed to test various systems for future exploration and to conduct scientific observations of cosmic rays, magnetic fields, radiation, dust particles, and a possible hydrogen gas "tail" trailing the Earth.
Alouette 1 is a deactivated Canadian satellite that studied the ionosphere. Launched in 1962, it was Canada's first satellite, and the first satellite constructed by a country other than the Soviet Union or the United States. Canada was the fourth country to operate a satellite, as the British Ariel 1, constructed in the United States by NASA, preceded Alouette 1 by five months. The name "Alouette" came from the French for "skylark" and the French-Canadian folk song of the same name.
The Agena Target Vehicle, also known as Gemini-Agena Target Vehicle (GATV), was an uncrewed spacecraft used by NASA during its Gemini program to develop and practice orbital space rendezvous and docking techniques, and to perform large orbital changes, in preparation for the Apollo program lunar missions. The spacecraft was based on Lockheed Aircraft's Agena-D upper stage rocket, fitted with a docking target manufactured by McDonnell Aircraft. The name 'Agena' derived from the star Beta Centauri, also known as Agena. The combined spacecraft was a 26-foot (7.92 m)-long cylinder with a diameter of 5 feet (1.52 m), placed into low Earth orbit with the Atlas-Agena launch vehicle. It carried about 14,000 pounds (6,400 kg) of propellant and gas at launch, and had a gross mass at orbital insertion of about 7,200 pounds (3,300 kg).
Gemini 11 was the ninth crewed spaceflight mission of NASA's Project Gemini, which flew from September 12 to 15, 1966. It was the 17th crewed American flight and the 25th spaceflight to that time. Astronauts Charles "Pete" Conrad Jr. and Richard F. Gordon Jr. performed the first direct-ascent rendezvous with an Agena Target Vehicle, docking with it 1 hour 34 minutes after launch; used the Agena rocket engine to achieve a record high-apogee Earth orbit; and created a small amount of artificial gravity by spinning the two spacecraft connected by a tether. Gordon also performed two extra-vehicular activities for a total of 2 hours 41 minutes.
Nozomi was a Japanese Mars orbiter that failed to reach Mars due to electrical failure. It was constructed by the Institute of Space and Astronautical Science, University of Tokyo and launched on July 4, 1998, at 03:12 JST with an on-orbit dry mass of 258 kg and 282 kg of propellant. The Nozomi mission was terminated on December 31, 2003.
Explorer 35,, was a spin-stabilized spacecraft built by NASA as part of the Explorer program. It was designed for the study of the interplanetary plasma, magnetic field, energetic particles, and solar X-rays, from lunar orbit.
Helios-A and Helios-B are a pair of probes that were launched into heliocentric orbit to study solar processes. As a joint venture between German Aerospace Center (DLR) and NASA, the probes were launched from Cape Canaveral Air Force Station, Florida, on December 10, 1974, and January 15, 1976, respectively.
Gravity-gradient stabilization or tidal stabilization is a passive method of stabilizing artificial satellites or space tethers in a fixed orientation using only the mass distribution of the orbited body and the gravitational field. The main advantage over using active stabilization with propellants, gyroscopes or reaction wheels is the low use of power and resources. It can also reduce or prevent the risk of propellant contamination of sensitive components.
The Atlas-Agena was an American expendable launch system derived from the SM-65 Atlas missile. It was a member of the Atlas family of rockets, and was launched 109 times between 1960 and 1978. It was used to launch the first five Mariner uncrewed probes to the planets Venus and Mars, and the Ranger and Lunar Orbiter uncrewed probes to the Moon. The upper stage was also used as an uncrewed orbital target vehicle for the Gemini crewed spacecraft to practice rendezvous and docking. However, the launch vehicle family was originally developed for the Air Force and most of its launches were classified DoD payloads.
The Applications Technology Satellites (ATS) were a series of experimental satellites launched by NASA, under the supervision of, among others, Wernher von Braun. The program was launched in 1966 to test the feasibility of placing a satellite into geosynchronous orbit. The satellites were primarily designed to act as communication satellites, but also carried equipment related to meteorology and navigation. ATS-6 was the world's first educational satellite as well as world's first experimental Direct Broadcast Satellite (DBS) as part of the Satellite Instructional Television Experiment (SITE) between NASA and ISRO.
Orbiting Vehicle or OV, originally designated SATAR, comprised five disparate series of standardized American satellites operated by the US Air Force, launched between 1965 and 1971. Forty seven satellites were built, of which forty three were launched and thirty seven reached orbit. With the exception of the OV3 series and OV4-3, they were launched as secondary payloads, using excess space on other missions. This resulted in extremely low launch costs and short proposal-to-orbit times. Typically, OV satellites carried scientific and/or technological experiments, 184 being successfully orbited through the lifespan of the program.
ATS-1, also designated ATS-B or Advanced Tech. Sat. 1, was an experimental geostationary satellite, launched in 1966. Though intended as a communications satellite rather than as a weather satellite, it carried the Spin Scan Cloud Camera developed by Verner E. Suomi and Robert Parent at the University of Wisconsin. After entering an orbit at 23,000 mi (37,000 km) above Earth, initially in orbit over Ecuador, it transmitted weather images from the Western Hemisphere, as well as other data, to ground stations, including well as video feeds for television broadcasting.
ATS-4 also known as ATS-D was a communications satellite launched by NASA on August 10, 1968 from Cape Canaveral through an Atlas-Centaur rocket.
Explorer 12, also called EPE-A or Energetic Particles Explorer-A and as S3), was a NASA satellite built to measure the solar wind, cosmic rays, and the Earth's magnetic field. It was the first of the S-3 series of spacecraft, which also included Explorer 12, 14, 15, and 26. It was launched on 16 August 1961, aboard a Thor-Delta launch vehicle. It ceased transmitting on 6 December 1961 due to power failure.
Orbiting Vehicle 3-3, launched 4 August 1966, was the third satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured charged particles in orbit so that their danger to space-based payloads could be assessed. OV3-3 is still in orbit as of 29 July 2021.
Orbiting Vehicle 3-2, launched 28 October 1966, was the fourth satellite to be launched in the OV3 series of the United States Air Force's Orbiting Vehicle program. The satellite measured charged particles in orbit, mapping irregularities in the ionosphere, particularly the auroral zone. OV3-2 reentered the Earth's atmosphere on 29 September 1971.
