Interplanetary spaceflight or interplanetary travel is the crewed or uncrewed travel between stars and planets, usually within a single planetary system. In practice, spaceflights of this type are confined to travel between the planets of the Solar System. Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions. Crewed flights have landed on the Moon and have been planned, from time to time, for Mars and Venus. While many scientists appreciate the knowledge value that uncrewed flights provide, the value of crewed missions is more controversial. Science fiction writers propose a number of benefits, including the mining of asteroids, access to solar power, and room for colonization in the event of an Earth catastrophe.
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.
An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity.
A lander is a spacecraft that descends towards, comes to rest on, the surface of an astronomical body. In contrast to an impact probe, which makes a hard landing that damages or destroys the probe upon reaching the surface, a lander makes a soft landing after which the probe remains functional.
The Constellation program was a crewed spaceflight program developed by NASA, the space agency of the United States, from 2005 to 2009. The major goals of the program were "completion of the International Space Station" and a "return to the Moon no later than 2020" with a crewed flight to the planet Mars as the ultimate goal. The program's logo reflected the three stages of the program: the Earth (ISS), the Moon, and finally Mars—while the Mars goal also found expression in the name given to the program's booster rockets: Ares. The technological aims of the program included the regaining of significant astronaut experience beyond low Earth orbit and the development of technologies necessary to enable sustained human presence on other planetary bodies.
The Altair spacecraft, previously known as the Lunar Surface Access Module or LSAM, was the planned lander spacecraft component of NASA's cancelled Constellation program. Astronauts would have used the spacecraft for landings on the Moon, which was intended to begin around 2019. The Altair spacecraft was planned to be used both for lunar sortie and lunar outpost missions. On February 1, 2010, U.S. President Barack Obama announced a proposal to cancel the Constellation program, to be replaced with a re-scoped program, effective with the U.S. 2011 fiscal year budget.
The Ares V was the planned cargo launch component of the cancelled NASA Constellation program, which was to have replaced the Space Shuttle after its retirement in 2011. Ares V was also planned to carry supplies for a human presence on Mars. Ares V and the smaller Ares I were named after Ares, the Greek god of war.
The Crew Exploration Vehicle (CEV) was a component of the U.S. NASA Vision for Space Exploration plan. A competition was held to design a spacecraft that could carry humans to the destinations envisioned by the plan. The winning design was the Orion spacecraft.
The LK was a lunar module developed in the 1960s as a part of several Soviet crewed lunar programs. Its role was analogous to the American Apollo Lunar Module (LM). Three LK modules, of the T2K variant, were flown without crew in Earth orbit, but no LK ever reached the Moon. The development of the N1 launch vehicle required for the lunar flight suffered setbacks, and the first Moon landings were achieved by US astronauts. As a result, both the N1 and the LK programs were cancelled without any further development.
NASA Design Reference Mission 3.0 was a NASA study for a human space mission to the planet Mars in the 1990s. It was a plan for a human exploration architecture for Mars, and was released in 1998 as an addendum to the early design plans released in 1994. The plan is for a series of multiple launches to send various space transpiration, surface exploration hardware, and human crew to Mars, and to return the crew to Earth in the early 21st century. Various technologies are explored to launch the payloads into space, to send them to Mars, and to reduce overall weight of the mission by various technologies or techniques including nuclear, solar, aerobraking, and in-situ resource use.
A space tug is a type of spacecraft used to transfer spaceborne cargo from one orbit to another orbit with different energy characteristics. An example would be moving a spacecraft from a low Earth orbit (LEO) to a higher-energy orbit like a geostationary transfer orbit, a lunar transfer, or an escape trajectory.
Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. The most common type is a radioisotope thermoelectric generator, which has been used on many space probes and on crewed lunar missions. Small fission reactors for Earth observation satellites, such as the TOPAZ nuclear reactor, have also been flown. A radioisotope heater unit is powered by radioactive decay and can keep components from becoming too cold to function, potentially over a span of decades.
The Asteroid Redirect Mission (ARM), also known as the Asteroid Retrieval and Utilization (ARU) mission and the Asteroid Initiative, was a space mission proposed by NASA in 2013. The Asteroid Retrieval Robotic Mission (ARRM) spacecraft would rendezvous with a large near-Earth asteroid and use robotic arms with anchoring grippers to retrieve a 4-meter boulder from the asteroid.
Austere Human Missions to Mars is a concept for a human mission to Mars by the United States space agency, NASA. Released in 2009, it proposed a modified and even less costly version of Design Reference Architecture (DRA) 5.0, itself a combination of nearly 20 years of Mars planning design work. The mission profile was for a conjunction class with a long surface stay, pre-deployed cargo, aerocapture and propulsive capture, and some in-situ resource production. As of 2015, the concept had not yet been adapted to the Space Launch System that replaced NASA's Constellation program in 2011.
The Mars Excursion Module (MEM) was a spacecraft proposed by NASA in the 1960s for use in a human mission to Mars, and this can refer to any number of studies by corporations and spaceflight centers for Mars landers. However, primarily a MEM referred to a combination of a Manned Mars lander, short-stay surface habitat, and Mars ascent stage. Variations on a MEM included spacecraft designs like an uncrewed Mars surface cargo delivery, and there was a MEM lander that combined a communications center, living habitat, and laboratory.
A super heavy-lift launch vehicle (SHLLV) is a launch vehicle capable of lifting more than 50 tonnes (110,000 lb) or 100 tonnes (220,000 lb) of payload into low Earth orbit (LEO), more than a heavy-lift launch vehicle.
Blue Moon is a robotic space cargo carrier and lander design concept for making cargo deliveries to the Moon. Designed by Blue Origin, and as of 2018 planned to be operated by Blue Origin, on a mission aimed for 2024. Blue Moon benefits from the vertical landing technology heritage used in Blue Origin's New Shepard sub-orbital rocket.
The Artemis program is a human spaceflight program that is being led by NASA with multiple international and US domestic partners. The primary goal of Artemis is to return humans to the Moon, specifically the lunar south pole, by 2025. If successful, it will include the first crewed lunar landing mission since Apollo 17 in 1972, which was the final lunar flight of the Apollo program.
