An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. An ion thruster creates a cloud of positive ions from a neutral gas by ionizing it to extract some electrons from its atoms. The ions are then accelerated using electricity to create thrust. Ion thrusters are categorized as either electrostatic or electromagnetic.
Explorer 1 was the first satellite launched by the United States in 1958 and was part of the U.S. participation in the International Geophysical Year (IGY). The mission followed the first two satellites the previous year; the Soviet Union's Sputnik 1 and Sputnik 2, beginning the Cold War Space Race between the two nations.
The NASA Deep Space Network (DSN) is a worldwide network of American spacecraft communication ground segment facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports NASA's interplanetary spacecraft missions. It also performs radio and radar astronomy observations for the exploration of the Solar System and the universe, and supports selected Earth-orbiting missions. DSN is part of the NASA Jet Propulsion Laboratory (JPL).
Explorer 3 was an American artificial satellite launched into medium Earth orbit in 1958. It was the second successful launch in the Explorer program, and was nearly identical to the first U.S. satellite Explorer 1 in its design and mission.
Project Echo was the first passive communications satellite experiment. Each of the two American spacecraft, launched in 1960 and 1964, were metalized balloon satellites acting as passive reflectors of microwave signals. Communication signals were transmitted from one location on Earth and bounced off the surface of the satellite to another Earth location.
Jason-1 was a satellite altimeter oceanography mission. It sought to monitor global ocean circulation, study the ties between the ocean and the atmosphere, improve global climate forecasts and predictions, and monitor events such as El Niño and ocean eddies. Jason-1 was launched in 2001 and it was followed by OSTM/Jason-2 in 2008, and Jason-3 in 2016 – the Jason satellite series. Jason-1 was launched alongside the TIMED spacecraft.
IMAGE is a NASA Medium Explorer mission that studied the global response of the Earth's magnetosphere to changes in the solar wind. It was believed lost but as of August 2018 might be recoverable. It was launched 25 March 2000, at 20:34:43.929 UTC, by a Delta II launch vehicle from Vandenberg Air Force Base on a two-year mission. Almost six years later, it unexpectedly ceased operations in December 2005 during its extended mission and was declared lost. The spacecraft was part of NASA's Sun-Earth Connections Program, and its data has been used in over 400 research articles published in peer-reviewed journals. It had special cameras that provided various breakthroughs in understanding the dynamics of plasma around the Earth. The principal investigator was Jim Burch of the Southwest Research Institute.
Juno is a NASA space probe orbiting the planet Jupiter. It was built by Lockheed Martin and is operated by NASA's Jet Propulsion Laboratory. The spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011 UTC, as part of the New Frontiers program. Juno entered a polar orbit of Jupiter on July 5, 2016, UTC, to begin a scientific investigation of the planet. After completing its mission, Juno will be intentionally deorbited into Jupiter's atmosphere.
Explorer 32, also known as Atmosphere Explorer-B (AE-B), was a NASA satellite launched by the United States to study the Earth's upper atmosphere. It was launched from Cape Canaveral on a Delta C1 launch vehicle, on 25 May 1966. It was the second of five "Atmosphere Explorer", the first being Explorer 17. Though it was placed in a higher-than-expected orbit by a malfunctioning second stage on its launch vehicle, Explorer 32 returned data for ten months before failing due to a sudden depressurization. The satellite reentered the Earth's atmosphere on 22 February 1985.
Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission began in February 2007 as a constellation of five NASA satellites to study energy releases from Earth's magnetosphere known as substorms, magnetic phenomena that intensify auroras near Earth's poles. The name of the mission is an acronym alluding to the Titan Themis.
OSTM/Jason-2, or Ocean Surface Topography Mission/Jason-2 satellite, was an international Earth observation satellite altimeter joint mission for sea surface height measurements between NASA and CNES. It was the third satellite in a series started in 1992 by the NASA/CNES TOPEX/Poseidon mission and continued by the NASA/CNES Jason-1 mission launched in 2001.
C/NOFS, or Communications/Navigation Outage Forecasting System was a USAF satellite developed by the Air Force Research Laboratory (AFRL) Space Vehicles Directorate to investigate and forecast scintillations in the Earth's ionosphere. It was launched by an Orbital Sciences Corporation Pegasus-XL launch vehicle at 17:02:48 UTC on 16 April 2008 and decayed on 28 November 2015.
The Manned Space Flight Network was a set of tracking stations built to support the American Mercury, Gemini, Apollo, and Skylab space programs.
The forerunner of the Deep Space Network was established in January 1958, when JPL, then under contract to the U.S. Army, deployed portable radio tracking stations in Nigeria, Singapore, and California to receive telemetry and plot the orbit of the Army-launched Explorer 1, the first successful U.S. satellite.
Lunar Flashlight was a low-cost CubeSat lunar orbiter mission to explore, locate, and estimate size and composition of water ice deposits on the Moon for future exploitation by robots or humans.
Psyche is a NASA space mission launched on October 13, 2023 to explore the origin of planetary cores by orbiting and studying the metallic asteroid 16 Psyche beginning in 2029. NASA's Jet Propulsion Laboratory (JPL) manages the project.
Double Asteroid Redirection Test (DART) was a NASA space mission aimed at testing a method of planetary defense against near-Earth objects (NEOs). It was designed to assess how much a spacecraft impact deflects an asteroid through its transfer of momentum when hitting the asteroid head-on. The selected target asteroid, Dimorphos, is a minor-planet moon of the asteroid Didymos; neither asteroid poses an impact threat to Earth, but their joint characteristics made them an ideal benchmarking target. Launched on 24 November 2021, the DART spacecraft successfully collided with Dimorphos on 26 September 2022 at 23:14 UTC about 11 million kilometers from Earth. The collision shortened Dimorphos' orbit by 32 minutes, greatly in excess of the pre-defined success threshold of 73 seconds. DART's success in deflecting Dimorphos was due to the momentum transfer associated with the recoil of the ejected debris, which was substantially larger than that caused by the impact itself.
The Interstellar Mapping and Acceleration Probe(IMAP) is a heliophysics mission that will simultaneously investigate two important and coupled science topics in the heliosphere: the acceleration of energetic particles and interaction of the solar wind with the local interstellar medium. These science topics are coupled because particles accelerated in the inner heliosphere play crucial roles in the outer heliospheric interaction. In 2018, NASA selected a team led by David J. McComas of Princeton University to implement the mission, which is currently planned to launch in February 2025. IMAP will be a Sun-tracking spin-stabilized satellite in orbit about the Sun–Earth L1 Lagrange point with a science payload of ten instruments. IMAP will also continuously broadcast real-time in-situ data that can be used for space weather prediction.
The Sentinel-6 Michael Freilich (S6MF) is a radar altimeter satellite developed in partnership between several European and American organizations. It is part of the Jason satellite series and is named after Michael Freilich. S6MF includes synthetic-aperture radar altimetry techniques to improve ocean topography measurements, in addition to rivers and lakes. The spacecraft entered service in mid 2021 and is expected to operate for 5.5 years.
Tianlian also known as CTDRS, is a Chinese data relay communication satellite constellation. The constellation serves to relay data from ground stations to spacecraft and rockets, most significantly China's crewed spaceflight program. The system currently consists of seven satellites in two generations, with the first satellite being launched in 2008.
