List of uncrewed NASA missions
Since 1958, NASA has overseen more than 1,000 uncrewed missions into Earth orbit or beyond. It has both launched its own missions and provided funding for private-sector missions. A number of NASA missions, including the [|Explorers Program], [|Voyager program], and [|New Frontiers program], are ongoing.
List of missions
Explorers Program (1958–present)
The Explorer program has launched more than 90 missions since it began more than five decades ago. It has matured into one of NASA's lower-cost mission programs.The program started as a U.S. Army proposal to place a scientific satellite into orbit during the International Geophysical Year. However, that proposal was rejected in favor of the U.S. Navy's Project Vanguard. The Explorer program was later reestablished to catch up with the Soviet Union after the launch of Sputnik 1 in October 1957. Explorer 1 was launched January 31, 1958; at this time the project still belonged to the Army Ballistic Missile Agency and the Jet Propulsion Laboratory. Besides being the first U.S. satellite, it is known for discovering the Van Allen radiation belt.
The Explorer program was later transferred to NASA, which continued to use the name for an ongoing series of relatively small space missions, typically an artificial satellite with a science focus. Over the years, NASA has launched a series of Explorer spacecraft carrying a wide variety of scientific investigations.
Pioneer program (1958–1978)
The Pioneer program was a series of NASA uncrewed space missions designed for planetary exploration. There were a number of missions in the program, most notably Pioneer 10 and Pioneer 11, which explored the outer planets and left the Solar System. Both carry a golden plaque, depicting a man and a woman and information about the origin and the creators of the probes, should any extraterrestrials find them someday.Additionally, the Pioneer mission to Venus consisted of two components, launched separately. Pioneer Venus 1 was launched in May 1978 and remained in orbit until 1992. Pioneer Venus 2, launched in August 1978, sent four small probes into the Venusian atmosphere.
Project Echo (1960–1964)
Project Echo was the first passive communications satellite experiment. Each spacecraft was a metalized balloon satellite to be inflated in space and acting as a passive reflector of microwave signals. Communication signals were bounced off of them from one point on Earth to another.NASA's Echo 1 satellite was built by Gilmore Schjeldahl Company in Northfield, Minnesota. Following the failure of the Delta rocket carrying Echo 1 on May 13, 1960, Echo 1A was put successfully into orbit by another Thor-Delta, and the first microwave transmission was received on August 12, 1960.
Echo 2 was a 41.1-meter diameter metalized PET film balloon, which was the last balloon satellite launched by Project Echo. It used an improved inflation system to improve the balloon's smoothness and sphericity. It was launched January 25, 1964, on a Thor Agena rocket.
Ranger program (1961–1965)
The Ranger program was a series of uncrewed space missions by the United States in the 1960s whose objective was to obtain the first close-up images of the surface of the Moon. The Ranger spacecraft were designed to take images of the lunar surface, returning those images until they were destroyed upon impact. A series of mishaps, however, led to the failure of the first five flights. Congress launched an investigation into "problems of management" at NASA Headquarters and JPL. After reorganizing the organization twice, Ranger 7 successfully returned images in July 1964, followed by two more successful missions.Ranger was originally designed, beginning in 1959, in three distinct phases, called "blocks." Each block had different mission objectives and progressively more advanced system design. The JPL mission designers planned multiple launches in each block, to maximize the engineering experience and scientific value of the mission and to assure at least one successful flight. Total research, development, launch, and support costs for the Ranger series of spacecraft was approximately $170 million.
Telstar (1962–1963)
Telstar was not a NASA program but rather a commercial communication satellite project. NASA's contributions to it were limited to launch services, as well as tracking and telemetry duties. The first two Telstar satellites were experimental and nearly identical. Telstar 1 was launched on top of a Thor-Delta rocket on July 10, 1962. It successfully relayed through space the first television pictures, telephone calls, and fax images, as well as providing the first live transatlantic television feed. Telstar 2 was launched May 7, 1963.Bell Telephone Laboratories designed and built the Telstar satellites. They were prototypes intended to prove various concepts behind the large constellation of orbiting satellites. Bell Telephone Laboratories also developed much of the technology required for satellite communication, including transistors, solar cells, and traveling wave tube amplifiers. AT&T built ground stations to handle Telstar communications.
Mariner program (1962–1973)
The Mariner program conducted by NASA launched a series of robotic interplanetary probes designed to investigate Mars, Venus and Mercury. The program included a number of firsts, including the first planetary flyby, the first pictures from another planet, the first planetary orbiter, and the first interplanetary gravity assist maneuver, which spent more than 13 years in orbit around Saturn.All Mariner spacecraft were based on a hexagonal or octagonal "bus", which housed all of the electronics, and to which all components were attached, such as antennae, cameras, propulsion, and power sources. All probes except Mariner 1, Mariner 2 and Mariner 5 had TV cameras. The first five Mariners were launched on Atlas-Agena rockets, while the last five used the Atlas-Centaur.
Lunar Orbiter program (1966–1967)
The Lunar Orbiter program was a series of five uncrewed lunar orbiter missions launched by the United States, starting in 1966. It was intended to help select landing sites for the Apollo program by mapping the Moon's surface. The program produced the first photographs ever taken from lunar orbit.All five missions were successful, and 99% of the Moon was mapped from photographs taken with a resolution of or better. The first three missions were dedicated to imaging 20 potential human lunar landing sites, selected based on Earth-based observations. These were flown at low inclination orbits. The fourth and fifth missions were devoted to broader scientific objectives and were flown in high-altitude polar orbits. All Lunar Orbiter craft were launched by an Atlas-Agena D launch vehicle.
During the Lunar Orbiter missions, the first pictures of Earth as a whole were taken, beginning with Earth-rise over the lunar surface by Lunar Orbiter 1 in August 1966. The first full picture of the whole Earth was taken by Lunar Orbiter 5 on August 8, 1967. A second photo of the whole Earth was taken by Lunar Orbiter 5 on November 10, 1967.
Surveyor program (1966–1968)
The Surveyor Program was a NASA program that, from 1966 through 1968, sent seven robotic spacecraft to the surface of the Moon. Its primary goal was to demonstrate the feasibility of soft landings on the Moon. The program was implemented by NASA's Jet Propulsion Laboratory to prepare for the Apollo program. The total cost of the Surveyor program was officially $469 million.Five of the Surveyor craft successfully soft-landed on the Moon. Two failed: Surveyor 2 crashed at high velocity after a failed mid-course correction, and Surveyor 4 was lost for contact 2.5 minutes before its scheduled touch-down.
All seven spacecraft are still on the Moon; none of the missions included returning them to Earth. Some parts of Surveyor 3 were returned to Earth by the crew of Apollo 12, which landed near it in 1969.
Helios probes (1974–1976)
Helios I and Helios II, also known as Helios-A and Helios-B, were a pair of space probes launched into heliocentric orbit for the purpose of studying solar processes. A joint venture of the Federal Republic of Germany and NASA, the probes were launched from Cape Canaveral Air Force Station, Florida, on December 10, 1974, and January 15, 1976, respectively. Helios 2 set a maximum speed record among spacecraft at about relative to the Sun. The Helios space probes completed their primary missions by the early 1980s, but they continued to send data up to 1985. The probes are no longer functional but still remain in their elliptical orbit around the Sun.Viking program (1975)
The Viking program consisted of a pair of American space probes sent to Mars—Viking 1 and Viking 2. Each vehicle was composed of two main parts, an orbiter designed to photograph the surface of Mars from orbit, and a lander designed to study the planet from the surface. The orbiters also served as communication relays for the landers once they touched down. Viking 1 was launched on August 20, 1975, and the second craft, Viking 2, was launched on September 9, 1975, both riding atop Titan III-E rockets with Centaur upper stages. By discovering many geological forms that are typically formed from large amounts of water, the Viking program caused a revolution in scientific ideas about water on Mars.The primary objectives of the Viking orbiters were to transport the landers to Mars, perform reconnaissance to locate and certify landing sites, act as communications relays for the landers, and to perform their own scientific investigations. The orbiter, based on the earlier Mariner 9 spacecraft, was an octagon approximately across. The total launch mass was, of which were propellant and attitude control gas.
Voyager program (1977–present)
The Voyager program consists of a pair of uncrewed scientific probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment of the late 1970s. Although they were originally designated to study just Jupiter and Saturn, Voyager 2 was able to continue to Uranus and Neptune. Both missions have gathered large amounts of data about the gas giants of the Solar System, of which little was previously known. Both probes have achieved escape velocity from the Solar System and will never return. Voyager 1 entered interstellar space in 2012., Voyager 1 was at a distance of 145.148 AU from Earth, traveling away from the Sun at a speed of about, which corresponds to a greater specific orbital energy than any other probe.