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, Venus and Mercury. 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.
Solar sails are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large surfaces. A number of spaceflight missions to test solar propulsion and navigation have been proposed since the 1980s. The first spacecraft to make use of the technology was IKAROS, launched in 2010.
Gemini 11 was the ninth crewed spaceflight mission of NASA's Project Gemini, which flew from September 12 to 15, 1966. It was the 17th crewed American flight and the 25th spaceflight to that time. Astronauts Charles "Pete" Conrad Jr. and Richard F. Gordon Jr. performed the first direct-ascent rendezvous with an Agena Target Vehicle, docking with it 1 hour 34 minutes after launch; used the Agena rocket engine to achieve a record high-apogee Earth orbit; and created a small amount of artificial gravity by spinning the two spacecraft connected by a tether. Gordon also performed two extra-vehicular activities for a total of 2 hours 41 minutes.
A CubeSat is a class of small satellite with a form factor of 10 cm (3.9 in) cubes. CubeSats have a mass of no more than 2 kg (4.4 lb) per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats are deployed into orbit from the International Space Station, or launched as secondary payloads on a launch vehicle. As of December 2023, more than 2,300 CubeSats have been launched.
Artificial gravity is the creation of an inertial force that mimics the effects of a gravitational force, usually by rotation. Artificial gravity, or rotational gravity, is thus the appearance of a centrifugal force in a rotating frame of reference, as opposed to the force experienced in linear acceleration, which by the equivalence principle is indistinguishable from gravity. In a more general sense, "artificial gravity" may also refer to the effect of linear acceleration, e.g. by means of a rocket engine.
Micro-Space was an aerospace corporation based in Denver, Colorado, founded in February 1977 by Richard P. Speck under the name Spectron Instrument Corporation. The corporation changed its name to "Micro-Space, Inc." in 1998. It was dissolved in 2011, following the death of the founder.
A momentum exchange tether is a kind of space tether that could theoretically be used as a launch system, or to change spacecraft orbits. Momentum exchange tethers create a controlled force on the end-masses of the system due to the pseudo-force known as centrifugal force. While the tether system rotates, the objects on either end of the tether will experience continuous acceleration; the magnitude of the acceleration depends on the length of the tether and the rotation rate. Momentum exchange occurs when an end body is released during the rotation. The transfer of momentum to the released object will cause the rotating tether to lose energy, and thus lose velocity and altitude. However, using electrodynamic tether thrusting, or ion propulsion the system can then re-boost itself with little or no expenditure of consumable reaction mass.
Gravity-gradient stabilization or tidal stabilization is a passive method of stabilizing artificial satellites or space tethers in a fixed orientation using only the mass distribution of the orbited body and the gravitational field. The main advantage over using active stabilization with propellants, gyroscopes or reaction wheels is the low use of power and resources. It can also reduce or prevent the risk of propellant contamination of sensitive components.
A rotating wheel space station, also known as a von Braun wheel, is a concept for a hypothetical wheel-shaped space station. Originally proposed by Konstantin Tsiolkovsky in 1903, the idea was expanded by Herman Potočnik in 1929.
Spacecraft attitude control is the process of controlling the orientation of a spacecraft with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
A number of space tethers have been deployed in space missions. Tether satellites can be used for various purposes including research into tether propulsion, tidal stabilisation and orbital plasma dynamics.
Space tethers are long cables which can be used for propulsion, momentum exchange, stabilization and attitude control, or maintaining the relative positions of the components of a large dispersed satellite/spacecraft sensor system. Depending on the mission objectives and altitude, spaceflight using this form of spacecraft propulsion is theorized to be significantly less expensive than spaceflight using rocket engines.
Space Tethered Autonomous Robotic Satellite II or STARS-II, was a nanosatellite built by Japan's Kagawa University to test an electrodynamic tether in low Earth orbit, a follow-on to the STARS mission.
Mars Cube One was a Mars flyby mission launched on 5 May 2018 alongside NASA's InSight Mars lander. It consisted of two nanospacecraft, MarCO-A and MarCO-B, that provided real-time communications to Earth for InSight during its entry, descent, and landing (EDL) on 26 November 2018 - when InSight was out of line of sight from the Earth. Both spacecraft were 6U CubeSats designed to test miniaturized communications and navigation technologies. These were the first CubeSats to operate beyond Earth orbit, and aside from telecommunications they also tested CubeSats' endurance in deep space. On 5 February 2019, NASA reported that both the CubeSats had gone silent by 5 January 2019, and are unlikely to be heard from again. In August 2019, the CubeSats were honored for their role in the successful landing of the InSight lander on Mars.
NASA's Pathfinder Technology Demonstrator (PTD) Project is a series of tech demonstrations of technologies aboard a series of nanosatellites known as CubeSats, providing significant enhancements to the performance of these versatile spacecraft. Each of the five planned PTD missions consist of a 6-unit (6U) CubeSat with expandable solar arrays.
NG-15, previously known as OA-15, was the fifteenth launch of the Northrop Grumman robotic resupply spacecraft Cygnus and its fourteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS) contract with NASA. The mission launched on 20 February 2021 at 17:36:50 UTC. This is the fourth launch of Cygnus under the CRS-2 contract.
STARS-EC was a nanosatellite developed by Shizuoka University, for the purpose of demonstrating space elevator tether technology. It was a 3U-size CubeSat, and could split into three separate satellites, connected via tethers. STARS-EC was launched on 20 February 2021, and was deployed from the International Space Station (ISS). The deployment service of STARS-EC was provided by Mitsui Bussan Aerospace.
Small Innovative Missions for Planetary Exploration (SIMPLEx) is a planetary exploration program operated by NASA. The program funds small, low-cost spacecraft for stand-alone planetary exploration missions. These spacecraft are intended to launch as secondary payloads on other missions and are riskier than Discovery or New Frontiers missions.
SpaceX CRS-27, also known as SpX-27, was a Commercial Resupply Service mission to the International Space Station (ISS) launched on 15 March 2023. The mission was contracted by NASA and was flown by SpaceX using Cargo Dragon C209. This was the seventh flight for SpaceX under NASA's CRS Phase 2.
