Following is a sampling of some of NASA's past and present programs excluding manned spacecraft. The years in brackets are for first and latest launching. A program is a number of flights or missions with the same kind of satellite, therefore the name of the program and the name of the satellite used will often be the same. In all NASA have made more than 1,000 unmanned missions into Earth orbit or beyond.[1]
The Explorer program continues and over more than five decades has launched 90+ missions into Space. It has matured into one of NASA's lower-cost mission programs, relative to its other programs.
It began as a U.S. Army proposal to place a scientific satellite into orbit during the International Geophysical Year (1957-58); 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 that nation's launch of Sputnik 1 on October, 1957. Explorer 1 was launched January 31, 1958; at this time the project still belonged to ABMA and JPL.[2] Besides being the first U.S. satellite, it is known for discovering the Van Allen radiation belt.
The Explorer program was 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.
The Pioneer program is a series of NASA unmanned space missions that was designed for planetary exploration. There were a number of such missions in the program, but the most notable were 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 or Pioneer Venus Orbiter was launched in 1978 and studied the planet for more than a decade after orbital insertion in 1978. Pioneer Venus 2 or Pioneer Venus Multiprobe sent four small probes into the Venusian atmosphere.
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.[3] 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 a 944 to 1,048 mi orbit by another Thor-Delta[4][5] and a microwave transmission from the Jet Propulsion Laboratory in Pasadena, California was received at Bell Laboratories in Homdel, New Jersey on August 12, 1960.
Echo 2 was a 41.1-meter (135 ft) 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.
Telstar was not a NASA program but a commercial communication satellite project. NASA's contribution to it was 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, fax images and provided the first live transatlantic television feed. Telstar 2 was launched May 7, 1963.[6]
Bell Telephone Laboratories designed and built the Telstar satellite. They were prototypes intended to prove various concepts behind the large constellation of orbiting satellites. The faceted 171 lb (77 kg) sphere had a diameter of a little more than 34 inches (about 1 m). Bell Telephone Laboratories also developed much of the technology required for satellite communication, including transistors, solar cells, and traveling wave tube amplifiers. To handle Telstar communications, AT&T built ground stations at Andover, Maine; Pleumeur-Bodou, France; and Goonhilly Downs, Britain. These were similar to, but larger than, the ground station used for project Echo.[6]
Telstar was a technical success. A US. Information Agency (USIA) poll showed that Telstar was better known in Great Britain than Sputnik had been in 1957. In contrast to Sputnik, Telstar's signals were useful.[6]
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 gravity assist maneuver.
Of the ten vehicles in the Mariner series, seven were successful and three were lost. The planned Mariner 11 and Mariner 12 vehicles evolved into Voyager 1 and Voyager 2 of the Voyager program, while the Viking 1 and Viking 2 Mars orbiters were enlarged versions of the Mariner 9 spacecraft. Other Mariner-based spacecraft, launched since Voyager, included the Magellan probe to Venus, and the Galileo probe to Jupiter. A second-generation Mariner spacecraft, called the Mariner Mark II series, eventually evolved into the Cassini–Huygens probe, now 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. All Mariner-based probes after Mariner 10 used the Titan IIIE, Titan IV unmanned rockets or the Space Shuttle with a solid-fueled Inertial Upper Stage and multiple planetary flybys.
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 mission called for the craft to travel directly to the moon on an impact trajectory (no orbit first), on a journey that lasted 63 to 65 hours, and ended with a deceleration of just over three minutes to a soft-landing. The program was implemented by NASA's Jet Propulsion Laboratory (JPL) to prepare for the Apollo program. The total cost of the Surveyor program was officially $469 million dollars.
Five of the Surveyor craft successfully soft-landed on the moon, including the first one. Two failed: Surveyor 2 crashed at high velocity after a failed mid-course correction, and Surveyor 4 was lost for contact (possibly exploding) 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. The camera from this craft is on display at the National Air and Space Museum in Washington, DC.
The Voyager program is a series of NASA unmanned space missions that consists of a pair of unmanned 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 officially designated to study just Jupiter and Saturn, the two probes were able to continue their mission into the outer solar system. Both probes have achieved escape velocity from the solar system and will never return. Both missions have gathered large amounts of data about the gas giants of the solar system, of which little was previously known.
As of November 12, 2010[update], Voyager 1 was at a distance of 115.251 AU (17.242 billion km, or 10.712 billion miles), traveling away from both the Earth and the Sun at a speed of 17 kilometres (11 mi)/s, which corresponds to a greater specific orbital energy than any other probe.[7]
The Viking program consisted of a pair of 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 a 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 2.5 m across. The total launch mass was 2,328 kilograms (5,130 lb), of which 1,445 kilograms (3,190 lb) were propellant and attitude control gas.
The Helios I and Helios II space probes, also known as Helios-A and Helios-B, were a pair of probes launched into heliocentric orbit for the purpose of studying solar processes. A joint venture of the Federal Republic of Germany (West Germany) and NASA, the probes were launched from Cape Canaveral Air Force Station, Florida, on Dec. 10, 1974, and Jan. 15, 1976, respectively. The probes are notable for setting a maximum speed record among spacecraft at 252,792 kilometres (157,078 mi)/h (157,078 mi/h or 43.63 mi/s or 70.22 kilometres (43.63 mi)/s or 0.000234c). 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.
The Magellan spacecraft was a space probe sent to the planet Venus, the first unmanned interplanetary spacecraft to be launched by NASA since its successful Pioneer Orbiter, also to Venus, in 1978. It was also the first of three deep-space probes to be launched on the Space Shuttle, and the first spacecraft to employ aerobraking techniques to lower its orbit.
Magellan created the first (and currently the best) high resolution mapping of the planet's surface features. Prior Venus missions had created low resolution radar globes of general, continent-sized formations. Magellan, performed detailed imaging and analysis of craters, hills, ridges, and other geologic formations, to a degree comparable to the visible-light photographic mapping of other planets.
Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. It was launched on October 18, 1989 by the Space Shuttle Atlantis on the STS-34 mission. It arrived at Jupiter on December 7, 1995, a little more than six years later, via gravitational assist flybys of Venus and Earth.
Despite antenna problems, Galileo conducted the first asteroid flyby, discovered the first asteroid moon, was the first spacecraft to orbit Jupiter, and launched the first probe into Jupiter's atmosphere. Galileo's prime mission was a two-year study of the Jovian system. The spacecraft traveled around Jupiter in elongated ellipses, each orbit lasting about two months. The differing distances from Jupiter afforded by these orbits allowed Galileo to sample different parts of the planet's extensive magnetosphere. The orbits were designed for close up flybys of Jupiter's largest moons. Once Galileo's prime mission was concluded, an extended mission followed starting on December 7, 1997; the spacecraft made a number of daring close flybys of Jupiter's moons Europa and Io. The closest approach was 180 kilometres (110 mi) (112 mi) on October 15, 2001.
On September 21, 2003, after 14 years in space and eight years of service in the Jovian system (around Jupiter), Galileo′s mission was terminated by sending the orbiter into Jupiter's atmosphere at a speed of nearly 50 kilometers per second. The programs funding was running out and the spacecraft was low on propellant, in addition to many systems were damaged. One of the reasons given for its destruction was to avoid the chance of it contaminating local moons with bacteria from Earth. Of particular interest was the ice-crusted moon Europa, which, thanks to Galileo, scientists now suspect harbors a salt water ocean beneath its surface.
The Hubble Space Telescope (HST) is a space telescope that was carried into orbit by a Space Shuttle in April 1990. It is named after American astronomer Edwin Hubble. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for astronomy. The HST is a collaboration between NASA and the European Space Agency, and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.[8] The HST's success has paved the way for greater collaboration between the agencies.
The HST was created with a relatively small budget of $2 billion[9] and has continued operation since 1990, delighting both scientists and the public. Some of its images, such as the groundbreaking Hubble Deep Field, have become famous.
UARS is a science satellite used from 1991 to 2005 to study Earth's atmosphere, including the ozone layer. Planned for a three year mission, it proved much more durable, allowing extended observation from its instrument suite. It was launched aboard Space Shuttle Discovery and deployed into space from the payload bay with its robotic arm, under guidance from the crew. The satellite was expected to undergo atmospheric re-entry in the late evening of Friday September 23, 2011 or early morning of Saturday September 24, 2011, Eastern Daylight Time.[10] On 24 September 2011 1:09 a.m. EDT UARS made its re-entry.[11]
At around about 6 tonnes, it was be the heaviest NASA satellites to undergo uncontrolled atmospheric entry since Skylab in the summer 1979, which was roughly 70 tonnes.[12] It is heavier then Pegasus 2, which fell back in fall of 1979, but weighed less than 2 tonnes.
The Mars Global Surveyor (MGS) was developed by NASA's Jet Propulsion Laboratory and launched November 1996. It began the United States' return to Mars after a 10-year absence. It completed its primary mission in January 2001 and was in its third extended mission phase when, on November 2, 2006, the spacecraft failed to respond to commands. In January 2007 NASA officially ended the mission.
The Surveyor spacecraft used a series of high-resolution cameras to explore the surface of Mars during its mission, returning more than 240,000 images spanning portions of 4.8 Martian years, from September 1997 to November 2006.[13] The surveyor's cameras utilized 3 instruments: a narrow angle camera that took (black-and-white) high resolution images (usually 1.5 to 12 m per pixel) red and blue wide angle pictures for context (240 m per pixel) and daily global imaging (7.5 kilometres (4.7 mi) per pixel).[14]
The Mars Pathfinder (MESUR Pathfinder,[15]) later renamed the Carl Sagan Memorial Station, was launched on December 4, 1996, just a month after the Mars Global Surveyor was launched. Onboard the lander was a small rover called Sojourner that would execute many experiments on the Martian surface. It was the second project from NASA's Discovery Program, which promotes the use of low-cost spacecraft and frequent launches under the motto "cheaper, faster and better" promoted by the then administrator, Daniel Goldin. The mission was directed by the Jet Propulsion Laboratory, a division of the California Institute of Technology, responsible for NASA's Mars Exploration Program.
This mission, besides being the first of a series of missions to Mars that included rovers (robotic exploration vehicles), was the most important since the Vikings landed on the red planet in 1976, and also was the first successful mission to send a rover to a planet. In addition to scientific objectives, the Mars Pathfinder mission was also a "proof-of-concept" for various technologies, such as airbag-mediated touchdown and automated obstacle avoidance, both later exploited by the Mars Exploration Rovers. The Mars Pathfinder was also remarkable for its extremely low price relative to other unmanned space missions to Mars.
NASA's Mars Exploration Rover Mission (MER), is an ongoing robotic space mission involving two rovers exploring the planet Mars. The mission is managed for NASA by the Jet Propulsion Laboratory, which designed, built and is operating the rovers.
The mission began in 2003 with the sending of the two rovers—MER-A Spirit and MER-B Opportunity—to explore the Martian surface and geology. The mission's scientific objective is to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The mission is part of NASA's Mars Exploration Program which includes three previous successful landers: the two Viking program landers in 1976 and Mars Pathfinder probe in 1997.[16]
The total cost of building, launching, landing and operating the rovers on the surface for the initial 90-Martian-day (sol) primary mission was US$820 million.[17] Since the rovers continued to function far beyond their initial 90 sol primary mission (six years to failure for Spirit, seven years and counting for Opportunity), they have each received multiple mission extensions.
In recognition of the vast amount of scientific information amassed by both rovers, two asteroids have been named in their honor: 37452 Spirit and 39382 Opportunity.
New Horizons is a NASA robotic spacecraft mission currently en route to the dwarf planet Pluto. It is expected to be the first spacecraft to fly by and study Pluto and its moons, Charon, Nix, and Hydra. Once New Horizons leaves the Solar System, NASA may also approve flybys of one or more other Kuiper Belt Objects.
New Horizons was launched on January 19, 2006 directly into an Earth-and-solar-escape trajectory. It had an Earth-relative velocity of about 16.26 kilometres (10.10 mi)/s or 58,536 kilometres (36,373 mi)/h (10.10 mi/s or 36,373 mi/h) after its last engine shut down. Thus, it left Earth at the fastest launch speed ever recorded for a man-made object (although its specific orbital energy is less than that of Voyager 1, and the Helios probes retain the maximum speed record for a spacecraft). New Horizons flew by Jupiter on February 28, 2007 and Saturn's orbit on June 8, 2008. It will arrive at Pluto on July 14, 2015 and then continue into the Kuiper belt.
On 26 November 2011, NASA's Mars Science Laboratory mission was successfully launched for Mars. The mission is scheduled to land the robotic "Curiosity" rover on the surface of Mars in August 2012, whereupon the rover will search for evidence of past or present life on Mars.[18][19]