An ion thruster or ion drive is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating positive ions with electricity. The term refers strictly to gridded electrostatic ion thrusters, and is often incorrectly loosely applied to all electric propulsion systems including electromagnetic plasma thrusters.
Opportunity, also known as MER-B or MER-1, and nicknamed "Oppy", is a robotic rover that was active on Mars from 2004 to late 2018. Launched on July 7, 2003, as part of NASA's Mars Exploration Rover program, it landed in Meridiani Planum on January 25, 2004, three weeks after its twin Spirit (MER-A) touched down on the other side of the planet. With a planned 90-sol duration of activity, Spirit functioned until it got stuck in 2009 and ceased communications in 2010, while Opportunity was able to stay operational for 5111 sols after landing, maintaining its power and key systems through continual recharging of its batteries using solar power, and hibernating during events such as dust storms to save power. This careful operation allowed Opportunity to exceed its operating plan by 14 years, 46 days, 55 times its designed lifespan. By June 10, 2018, when it last contacted NASA, the rover had traveled a distance of 45.16 kilometers.
Nozomi was a planned and launched Mars-orbiting aeronomy probe. It did not reach Mars orbit due to electrical failures. The mission was terminated on December 31, 2003.
Interstellar Boundary Explorer (IBEX) is a NASA satellite in Earth orbit that uses Energetic Neutral Atoms (ENAs) to image the interaction region between the Solar System and interstellar space. The mission is part of NASA's Small Explorer program and was launched with a Pegasus-XL rocket on October 19, 2008.
Dynamics Explorer was a NASA mission, launched on August 3, 1981 and terminated on February 28, 1991. It consisted of two unmanned satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.
Mars Atmosphere and Volatile EvolutioN (MAVEN) mission was developed by NASA to study the Martian atmosphere while orbiting Mars. Mission goals include determining how the planet's atmosphere and water, presumed to have once been substantial, were lost over time.
Energetic neutral atom (ENA) imaging, often described as "seeing with atoms", is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere, even to its outer boundary. This constitutes the far-flung edge of the solar system.
Io Volcano Observer (IVO) is a robotic space exploration mission concept that, if approved and launched, would orbit Jupiter and perform at least nine flybys of Jupiter's moon Io. IVO has been proposed to NASA by the University of Arizona and Johns Hopkins University's Applied Physics Laboratory as a Discovery-class mission in 2010 and 2015. IVO can also be a contestant for the New Frontiers program. IVO was originally part of NASA's Discovery & Scout Mission Capability Expansion (DSMCE) concept-study program in 2009.
Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) are a pair of NASA instruments aboard two United States National Reconnaissance Office satellites in Molniya orbits. TWINS was designed to provide stereo images of the Earth's ring current. The first instrument, TWINS-1, was launched aboard USA-184 on 28 June 2006. TWINS-2 followed aboard USA-200 on March 13, 2008.
The Observatory for Heteroscale Magnetosphere-Ionosphere Coupling ('OHMIC) is a mission concept proposed in 2011 to NASA's Explorers program consisting of a pair of spacecraft flying in formation studying the energy powering space weather. The Principal Investigator for the mission is James Burch of the Southwest Research Institute in San Antonio, Texas. The concept was not selected for development at that time.
The Heliophysics Science Division of the Goddard Space Flight Center (NASA) conducts research on the Sun, its extended solar system environment, and interactions of Earth, other planets, small bodies, and interstellar gas with the heliosphere. Division research also encompasses geospace—Earth's uppermost atmosphere, the ionosphere, and the magnetosphere—and the changing environmental conditions throughout the coupled heliosphere.
Phobos And Deimos & Mars Environment (PADME) is a low-cost NASA Mars orbiter mission concept that would address longstanding unknowns about Mars' two moons Phobos and Deimos and their environment.
VERITAS is a proposed mission concept by NASA's Jet Propulsion Laboratory (JPL) to map with high resolution the surface of planet Venus. The combination of surface topography and image data would provide knowledge of Venus' tectonic and impact history, the timing and mechanisms of volcanic resurfacing, and the mantle processes responsible for them.
Explorer of Enceladus and Titan (E2T) is a space mission concept that would investigate the evolution and habitability of the Saturnian satellites Enceladus and Titan and is proposed by the European Space Agency in collaboration with NASA.
The Interstellar Mapping and Acceleration Probe(IMAP) is a heliophysics mission that simultaneously investigates 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 an IMAP team led by David J. McComas of Princeton University to implement the mission. The planned launch for IMAP is in October, 2024. The IMAP spacecraft has a science payload of ten instruments and is a simple Sun-pointed spinner in orbit about the Sun-Earth L1 Lagrangian point. IMAP also continuously broadcasts real-time in-situ data that can be used for space weather prediction.
Explorer 51, also called as AE-C, was a NASA scientific satellite belonging to series Atmosphere Explorer, being launched on December 16, 1973 from Vandenberg AFB board a Delta 1900 rocket.
Bi-sat Observations of the Lunar Atmosphere above Swirls (BOLAS) is a spacecraft mission concept that would orbit the Moon at very low altitude in order to study vital aspects of the lunar surface. The concept, currently under study by NASA, involves two small identical CubeSat satellites connected vertically above the lunar surface by a 25 km long tether. The mission goal is to understand the hydrogen cycle on the Moon, dust weathering, and the formation of lunar swirls. The team from NASA's Goddard Space Flight Center was selected in August 2017 to further mature the concept.
