Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. In-space propulsion exclusively deals with propulsion systems used in the vacuum of space and should not be confused with space launch or atmospheric entry.
In spacecraft propulsion, a Hall-effect thruster (HET) is a type of ion thruster in which the propellant is accelerated by an electric field. Hall-effect thrusters are sometimes referred to as Hall thrusters or Hall-current thrusters. Hall-effect thrusters use a magnetic field to limit the electrons' axial motion and then use them to ionize propellant, efficiently accelerate the ions to produce thrust, and neutralize the ions in the plume. The Hall-effect thruster is classed as a moderate specific impulse space propulsion technology and has benefited from considerable theoretical and experimental research since the 1960s.
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.
A spacecraft is a vehicle that is designed to fly and operate in outer space. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle.
A space station is a spacecraft which remains in orbit and hosts humans for extended periods of time. It therefore is an artificial satellite featuring habitation facilities. The purpose of maintaining a space station varies depending on the program. Most often space stations have been research stations, but they have also served military or commercial uses, such as hosting space tourists.
Gaganyaan is an Indian crewed orbital spacecraft intended to be the formative spacecraft of the Indian Human Spaceflight Programme. The spacecraft is being designed to carry three people, and a planned upgraded version will be equipped with rendezvous and docking capabilities. In its maiden crewed mission, the Indian Space Research Organisation (ISRO)'s largely autonomous 5.3-metric ton capsule will orbit the Earth at 400 km altitude for up to seven days with a two- or three-person crew on board. The first crewed mission was originally planned to be launched on ISRO's HLVM3 rocket in December 2021. As of November 2024, it is expected to be launched no earlier than 2026.
The Boeing Starliner is a spacecraft designed to transport crew to and from the International Space Station (ISS) and other low-Earth-orbit destinations. Developed by Boeing under NASA's Commercial Crew Program (CCP), it consists of a reusable crew capsule and an expendable service module.
Development of the Commercial Crew Program (CCDev) began in the second round of the program, which was rescoped from a smaller technology development program for human spaceflight to a competitive development program that would produce the spacecraft to be used to provide crew transportation services to and from the International Space Station (ISS). To implement the program, NASA awarded a series of competitive fixed-price contracts to private vendors starting in 2011. Operational contracts to fly astronauts were awarded in September 2014 to SpaceX and Boeing, and NASA expected each company to complete development and achieve crew rating in 2017. Each company performed an uncrewed orbital test flight in 2019.
Dragon 2 is a class of partially reusable spacecraft developed, manufactured, and operated by American space company SpaceX for flights to the International Space Station (ISS) and private spaceflight missions. The spacecraft, which consists of a reusable space capsule and an expendable trunk module, has two variants: the 4-person Crew Dragon and Cargo Dragon, a replacement for the Dragon 1 cargo capsule. The spacecraft launches atop a Falcon 9 Block 5 rocket, and the capsule returns to Earth through splashdown.
Boeing Crew Flight Test (Boe-CFT) was the first crewed mission of the Boeing Starliner capsule. Launched on 5 June 2024, the mission flew a crew of two NASA astronauts, Barry E. Wilmore and Sunita Williams, from Cape Canaveral Space Force Station to the International Space Station. The mission was meant to last eight days, ending on 14 June with a landing in the American Southwest. However, the capsule's thrusters malfunctioned as Starliner approached the ISS. After more than two months of investigation, NASA decided it was too risky to return Wilmore and Williams to Earth aboard Starliner. Instead, the Boeing spacecraft returned uncrewed on 7 September 2024, and the astronauts will ride down on the SpaceX Crew-9 spacecraft in February 2025.
The Lunar Gateway, or simply Gateway, is a space station which is planned to be assembled in orbit around the Moon. The Gateway is intended to serve as a communication hub, science laboratory, and habitation module for astronauts as part of the Artemis program. It is a multinational collaborative project: participants include NASA, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA), and the Mohammed Bin Rashid Space Centre (MBRSC). The Gateway is planned to be the first space station beyond low Earth orbit.
The Artemis program is a Moon exploration program led by the United States' National Aeronautics and Space Administration (NASA), formally established in 2017 via Space Policy Directive 1. It is intended to reestablish a human presence on the Moon for the first time since the Apollo 17 mission in 1972. The program's stated long-term goal is to establish a permanent base on the Moon to facilitate human missions to Mars.
The Commercial Crew Program (CCP) provides commercially operated crew transportation service to and from the International Space Station (ISS) under contract to NASA, conducting crew rotations between the expeditions of the International Space Station program. American space manufacturer SpaceX began providing service in 2020, using the Crew Dragon spacecraft, and NASA plans to add Boeing when its Boeing Starliner spacecraft becomes operational no earlier than 2025. NASA has contracted for six operational missions from Boeing and fourteen from SpaceX, ensuring sufficient support for ISS through 2030.
The Power and Propulsion Element (PPE), previously known as the Asteroid Redirect Vehicle propulsion system, is a planned solar electric ion propulsion module being developed by Maxar Technologies for NASA. It is one of the major components of the Lunar Gateway. The PPE will allow access to the entire lunar surface and a wide range of lunar orbits and double as a space tug for visiting craft.
Starlab is a planned LEO commercial space station, which is expected to launch no earlier than 2028. It is currently being designed by Starlab Space, a joint venture between Voyager Space and Airbus. It is planned to be launched before the decommissioning of the ISS.
Launcher was an American aerospace company based in Hawthorne, California. It was founded in New York City in 2017 by Max Haot.
Impulse Space was founded in 2021 by Tom Mueller, employee No.1 at SpaceX and engineer of the Merlin and Draco rocket engines that power the Falcon 9 and Dragon spacecraft. The company develops in-space transportation services for satellites that fly to Low Earth Orbit then need to reach other orbits.
Vast is a privately held American aerospace company headquartered in Long Beach, California. It was founded in 2021 by entrepreneur Jed McCaleb with the goal of developing artificial gravity space stations to "expand humanity beyond the solar system".
Vast-1 is a planned private spaceflight to the Haven-1 space station, planned to launch no earlier than August 2025 by American aerospace company Vast. Vast-1 is expected to launch on a Falcon 9 rocket, using a Crew Dragon vehicle, both manufactured by SpaceX. The stay on the station is planned to last no more than 30 days. The spaceflight will include four astronauts who will be trained by SpaceX on their Crew Dragon capsule through simulations and formations.
