It has been suggested that Spaceworthiness be merged into this article or section. (Discuss) It has been suggested that Robotic spacecraft be merged into this article or section. (Discuss) This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (June 2010) Soyuz 19 spacecraft for the Apollo Soyuz Test Project A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo. On a sub-orbital spaceflight, a spacecraft enters space and then returns to the surface, without having gone into an orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers, while those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific research are space probes. Robotic spacecraft that remain in orbit around a planetary body are artificial satellites. Only a handful of interstellar probes, such as Pioneer 10 and 11, Voyager 1 and 2, and New Horizons, are currently on trajectories that leave our Solar System. Spacecraft and space travel are common themes in works of science fiction. Contents 1 History 2 Past and present spacecraft 2.1 Manned spacecraft 2.1.1 Spaceplanes 2.2 Unmanned spacecraft 2.3 Unfunded / canceled programs 3 Spacecraft under development 3.1 Manned 3.2 Unmanned 4 Subsystems 5 See also 6 References 7 External links // History See also: History of spaceflight The first Earth orbiting satellite was Sputnik 1, which was launched 4 October 1957, and remained in orbit for several months.1 While Sputnik 1 was the first spacecraft to orbit the Earth, other man-made objects had previously reached an altitude of 100 km, which is the height required by the international organization Fédération Aéronautique Internationale to count as a spaceflight. This altitude is called the Kármán line. In particular, in the 1940's there were several test launches of the V-2 rocket, some of which reached altitudes well over 100 km. Past and present spacecraft Manned spacecraft See also: List of manned spacecraft and Human spaceflight The Apollo 15 Command/Service Module as viewed from the Lunar Module on August 2, 1971. A Russian Soyuz bringing a crew to the ISS.

The first manned spacecraft was Vostok 1, which carried Soviet cosmonaut Yuri Gagarin into space in 1961, and complete a full Earth orbit. There were five other manned missions which used a Vostok spacecraft.2 The second manned spacecraft was named Freedom 7, and it performed a sub-orbital spaceflight carrying American astronaut Alan Shepherd to an altitude of just over 187 kilometres (116 mi). There were five other manned missions using at Mercury spacecraft, like Freedom 7. Other Soviet manned spacecraft include the Voskhod spacecraft, Soyuz spacecraft, and the Salyut space stations as well as the space station Mir. Other American manned spacecraft include the Gemini Spacecraft, Apollo Spacecraft, the Skylab space station, and the Space Shuttle. China was also developed the Shenzhou spacecraft, which as of January 2011 has been used for three manned missions, the first being Shenzhou 5 in 2003. The International Space Station, which has been manned since November 2000, in a joint venture between Russian, the United States, as well as several other countries. Strictly speaking, the Manned Maneuvering Unit, the propulsion system used by spacewalking astronauts, could be counted as a manned spacecraft. Spaceplanes Main article: Spaceplane There have been some reusable vehicles designed only for manned spaceflight, and these are often called spaceplanes. The first example of such was the North American X-15 spaceplane, which conducted two manned flights which reached a height over 100 km, both of which were in the 1960's. Space Shuttle Columbia's first launch. Columbia orbiter landing The first reusable spacecraft, the X-15, was air-launched on a suborbital trajectory on July 19, 1963. The first partially reusable orbital spacecraft, the Space Shuttle, was launched by the USA on the 20th anniversary of Yuri Gagarin's flight, on April 12, 1981. During the Shuttle era, six orbiters were built, all of which have flown in the atmosphere and five of which have flown in space. The Enterprise was used only for approach and landing tests, launching from the back of a Boeing 747 and gliding to deadstick landings at Edwards AFB, California. The first Space Shuttle to fly into space was the Columbia, followed by the Challenger, Discovery, Atlantis, and Endeavour. The Endeavour was built to replace the Challenger when it was lost in January 1986. The Columbia broke up during reentry in February 2003.

The first automatic partially reusable spacecraft was the Buran (Snowstorm), launched by the USSR on November 15, 1988, although it made only one flight. This spaceplane was designed for a crew and strongly resembled the U.S. Space Shuttle, although its drop-off boosters used liquid propellants and its main engines were located at the base of what would be the external tank in the American Shuttle. Lack of funding, complicated by the dissolution of the USSR, prevented any further flights of Buran. The Space Shuttle has since been modified to allow for autonomous re-entry via the addition of a control cable running from the control cabin to the mid-deck which would allow for the automated deployment of the landing gear in the event a un-crewed re-entry was required following abandonment due to damage at the ISS. Per the Vision for Space Exploration, the Space Shuttle is due to be retired in 2011 due mainly to its old age and high cost of program reaching over a billion dollars per flight. The Shuttle's human transport role is to be replaced by the partially reusable Crew Exploration Vehicle (CEV) no later than 2014. The Shuttle's heavy cargo transport role is to be replaced by expendable rockets such as the Evolved Expendable Launch Vehicle (EELV) or a Shuttle Derived Launch Vehicle. Scaled Composites' SpaceShipOne was a reusable suborbital spaceplane that carried pilots Mike Melvill and Brian Binnie on consecutive flights in 2004 to win the Ansari X Prize. The Spaceship Company will build its successor SpaceShipTwo. A fleet of SpaceShipTwos operated by Virgin Galactic should begin reusable private spaceflight carrying paying passengers in 2011. XCOR Aerospace also plans to initiate a suborbital commercial spaceflight service with the Lynx rocketplane in 2012 through a partnership with RocketShip Tours. First test flights are planned for 2011. Unmanned spacecraft See also: List of unmanned spacecraft by program, Timeline of spaceflight, Timeline of artificial satellites and space probes, List of Solar System probes, and Space probe The Hubble Space Telescope The Jules Verne Automated Transfer Vehicle (ATV) approaches the International Space Station on Monday, March 31, 2008. Artist's conception of Cassini-Huygens as it enters Saturn's orbit Semi-manned or manned-spec unmanned spacecraft See also: Unmanned resupply spacecraft Automated Transfer Vehicle (ATV) – unmanned European cargo spacecraft Buran manned-spec Soviet shuttle (one mission only) H-II Transfer Vehicle (HTV) – unmanned Japanese cargo spacecraft Progress – unmanned USSR/Russia cargo spacecraft TKS – manned-spec unmanned USSR cargo spacecraft Earth Orbit See also: Satellite Explorer 1 – first US satellite Project SCORE – first communications satellite SOHO Sputnik 1 – world's first artificial satellite Sputnik 2 – first animal in orbit (Laika) Sputnik 5 – first capsule recovered from orbit (Vostok precursor) – animals survived STEREO – Earth environment observation Syncom – first geosynchronous communications satellite X-37 – spaceplane There are more than over 2,000 spacecrafts in orbit. Lunar Clementine – US Navy mission, orbited Moon, detected hydrogen at the poles Kaguya JPN – Lunar orbiter Luna 1 – first lunar flyby Luna 2 – first lunar impact Luna 3 – first images of lunar far side Luna 9 – first soft landing on the Moon Luna 10 – first lunar orbiter Luna 16 – first unmanned lunar sample retrieval Lunar Orbiter – very successful series of lunar mapping spacecraft Lunar Prospector – confirmed detection of hydrogen at the lunar poles Lunar Reconnaissance Orbiter – Identifies safe landing sites & Locates moon resources SMART-1 ESA – Lunar Impact Surveyor – first USA soft lander Chandrayaan 1 – first Indian Lunar mission Artist's conception of the Phoenix spacecraft as it lands on Mars Planetary Akatsuki JPN – a Venus orbiter Cassini-Huygens – first Saturn orbiter + Titan lander Galileo – first Jupiter orbiter+descent probe IKAROS JPN – first solar-sail spacecraft Mariner 4 – first Mars flyby, first close and high resulution images of Mars Mariner 9 – first Mars orbiter Mariner 10 – first Mercury flyby, first close up images Mars Exploration Rover – a Mars rover Mars Express – a Mars orbiter Mars Global Surveyor – a Mars orbiter Mars Reconnaissance Orbiter – an advanced climate, imaging, sub-surface radar, and telecommunications Mars orbiter MESSENGER – first Mercury orbiter (arrival 2011) Mars Pathfinder – a Mars lander + rover New Horizons – first Pluto flyby (arrival 2015) Pioneer 10 – first Jupiter flyby, first close up images Pioneer 11 – second Jupiter flyby + first Saturn flyby (first close up images of Saturn) Pioneer Venus – first Venus orbiter+landers Venera 4 – first soft landing on another planet (Venus) Viking 1 – first soft landing on Mars Voyager 2 – Jupiter flyby + Saturn flyby + first flybys/images of Neptune and Uranus Other – deep space Main article: Space probe Cluster Deep Space 1 Deep Impact Genesis Hayabusa Near Earth Asteroid Rendezvous Stardust WMAP Fastest spacecraft Helios I & II Solar Probes (252,792 km/h/157,078 mph) Furthest spacecraft from the Sun Voyager 1 at 106.3 AU as of July 2008, traveling outward at about 3.6 AU/year Pioneer 10 at 89.7 AU as of 2005, traveling outward at about 2.6 AU/year Voyager 2 at 85.49 AU as of July 2008, traveling outward at about 3.3 AU/year Unfunded / canceled programs The First Test Flight of the Delta Clipper-Experimental Advanced (DC-XA) Multi-stage Chinese Project 921-3 Shuttle Kliper—Russian "Clipper" ESA Hermes Shuttle Soviet Buran Shuttle Soyuz Kontakt Teledesic Manned Orbiting Laboratory X-20 Altair - lunar lander SSTO RR/British Aerospace HOTOL ESA Hopper Orbiter McDonnell Douglas DC-X (Delta Clipper) Roton Rotored-Hybrid Lockheed-Martin VentureStar Spacecraft under development The Orion spacecraft Manned Orion - capsule SpaceX Dragon - capsule Lynx rocketplane - suborbital ISRO Orbital Vehicle - capsule PTK NP spacecraft- capsule Dream Chaser - spaceplane Boeing CST-100 - capsule ESA Advanced Reentry Vehicle - capsule Skylon - single-stage-to-orbit spaceplane Unmanned SpaceX Dragon - cargo delivery to the ISS Orbital Sciences Cygnus - cargo delivery to the ISS CNES Mars Netlander James Webb Space Telescope (delayed) ESA Darwin probe Mars Science Laboratory rover Shenzhou spacecraft Cargo Terrestrial Planet Finder probe System F6—a DARPA Fractionated Spacecraft demonstrator Subsystems

A spacecraft system comprises various subsystems, dependent upon mission profile. Spacecraft subsystems comprise the spacecraft "bus" and may include: attitude determination and control (variously called ADAC, ADC or ACS), guidance, navigation and control (GNC or GN&C), communications (Comms), command and data handling (CDH or C&DH), power (EPS), thermal control (TCS), propulsion, and structures. Attached to the bus are typically payloads. Life support  Spacecraft intended for human spaceflight must also include a life support system for the crew. Reaction control system thrusters on the nose of the U.S. Space Shuttle Attitude control  A Spacecraft needs an attitude control subsystem to be correctly oriented in space and respond to external torques and forces properly. The attitude control subsystem consists of sensors and actuators, together with controlling algorithms. The attitude control subsystem permits proper pointing for the science objective, sun pointing for power to the solar arrays and earth-pointing for communications. GNC  Guidance refers to the calculation of the commands (usually done by the CDH subsystem) needed to steer the spacecraft where it is desired to be. Navigation means determining a spacecraft's orbital elements or position. Control means adjusting the path of the spacecraft to meet mission requirements. On some missions, GNC and Attitude Control are combined into one subsystem of the spacecraft. Command and data handling  The CDH subsystem receives commands from the communications subsystem, performs validation and decoding of the commands, and distributes the commands to the appropriate spacecraft subsystems and components. The CDH also receives housekeeping data and science data from the other spacecraft subsystems and components, and packages the data for storage on a data recorder or transmission to the ground via the communications subsystem. Other functions of the CDH include maintaining the spacecraft clock and state-of-health monitoring. Power  Spacecraft need an electrical power generation and distribution subsystem for powering the various spacecraft subsystems. For spacecraft near the Sun, solar panels are frequently used to generate electrical power. Spacecraft designed to operate in more distant locations, for example Jupiter, might employ a Radioisotope Thermoelectric Generator (RTG) to generate electrical power. Electrical power is sent through power conditioning equipment before it passes through a power distribution unit over an electrical bus to other spacecraft components. Batteries are typically connected to the bus via a battery charge regulator, and the batteries are used to provide electrical power during periods when primary power is not available, for example when a Low Earth Orbit (LEO) spacecraft is eclipsed by the Earth. Thermal control  Spacecraft must be engineered to withstand transit through the Earth's atmosphere and the space environment. They must operate in a vacuum with temperatures potentially ranging across hundreds of degrees Celsius as well as (if subject to reentry) in the presence of plasmas. Material requirements are such that either high melting temperature, low density materials such as beryllium and reinforced carbon-carbon or (possibly due to the lower thickness requirements despite its high density) tungsten or ablative carbon/carbon composites are used. Depending on mission profile, spacecraft may also need to operate on the surface of another planetary body. The thermal control subsystem can be passive, dependent on the selection of materials with specific radiative properties. Active thermal control makes use of electrical heaters and certain actuators such as louvers to control temperature ranges of equipments within specific ranges. A launch vehicle, like this Proton rocket, is typically used to bring a spacecraft to orbit. Propulsion  Spacecraft may or may not have a propulsion subsystem, depending upon whether or not the mission profile calls for propulsion. The Swift spacecraft is an example of a spacecraft that does not have a propulsion subsystem. Typically though, LEO spacecraft (for example Terra (EOS AM-1) include a propulsion subsystem for altitude adjustments (called drag make-up maneuvers) and inclination adjustment maneuvers. A propulsion system is also needed for spacecraft that perform momentum management maneuvers. Components of a conventional propulsion subsystem include fuel, tankage, valves, pipes, and thrusters. The TCS interfaces with the propulsion subsystem by monitoring the temperature of those components, and by preheating tanks and thrusters in preparation for a spacecraft maneuver. Structures  Spacecraft must be engineered to withstand launch loads imparted by the launch vehicle, and must have a point of attachment for all the other subsystems. Depending upon mission profile, the structural subsystem might need to withstand loads imparted by entry into the atmosphere of another planetary body, and landing on the surface of another planetary body. Payload  The payload is dependent upon the mission of the spacecraft, and is typically regarded as the part of the spacecraft "that pays the bills". Typical payloads could include scientific instruments (cameras, telescopes, or particle detectors, for example), cargo, or a human crew. Ground segment  The ground segment, though not technically part of the spacecraft, is vital to the operation of the spacecraft. Typical components of a ground segment in use during normal operations include a mission operations facility where the flight operations team conducts the operations of the spacecraft, a data processing and storage facility, ground stations to radiate signals to and receive signals from the spacecraft, and a voice and data communications network to connect all mission elements.3 Launch vehicle  The launch vehicle is used to propel the spacecraft from the Earth's surface, through the atmosphere, and into an orbit, the exact orbit being dependent upon mission configuration. The launch vehicle may be expendable or reusable. See also Spaceflight portal Look up Spacecraft in Wiktionary, the free dictionary. Wikimedia Commons has media related to: Spacecraft Timeline of Solar System exploration Astrionics List of spacecraft List of spaceflights Spacecraft design Spacecraft propulsion Space exploration U.S. Space Exploration History on U.S. Stamps Space suit Spaceflight records Starship Ansari X Prize Atmospheric reentry Earth to orbit List of fictional spacecraft Flying saucers References ^ F.J. Krieger (October 5, 1957). ""Announcement of the First Satellite," from Pravada". NASA. http://history.nasa.gov/sputnik/14.html.  ^ "Vostok". Encyclopedia Astronautica. http://www.astronautix.com/craft/vostok.htm.  ^ "The Rosetta ground segment". ESA.int. 2004-02-17. http://www.esa.int/SPECIALS/Rosetta/SEMDV71PGQD_0.html. Retrieved 2008-02-11.  Wertz, James; Larson, Wiley J (1999). Space Mission Analysis and Design (3rd ed.). Torrance, CA: Microcosm. ISBN 978-1881883104.  Knight, Will (2006-01-23). "Spacecraft skin 'heals' itself". New Scientist. http://www.newscientistspace.com/article.ns?id=dn8623. Retrieved 2008-02-11.  External links NASA: Space Science Spacecraft Missions NSSDC Master Catalog Spacecraft Query Form Early History of Spacecraft Basics of Spaceflight tutorial from JPL/Caltech International Spaceflight Museum v · d · eSpaceflight General spaceflight History (Space Race, Accidents and incidents) · Astrodynamics Applications Earth observation satellites (Spy satellites, weather satellites) · Space exploration · Space tourism · Satellite navigation · Space architecture · Space colonization Human spaceflight General Astronaut  · Life support system Hazards Weightlessness (space adaptation syndrome)  · cosmic radiation Major projects Vostok · Mercury · Voskhod · Gemini · Soyuz · Apollo · Space Shuttle · Shenzhou · Mir · ISS · Constellation Other Extra-vehicular activity Spacecraft Launch vehicle · Space Shuttle · Robotic spacecraft · Spacecraft propulsion · Rocket Destinations Sub-orbital · Orbital (Geosynchronous orbit, Geocentric orbit)  · Interplanetary spaceflight · Interstellar travel · Intergalactic travel Space launch Expendable and Reusable systems · Escape velocity · Direct ascent · Non-rocket spacelaunch · Spaceport · Launch pad Main agencies ESA · NASA  · RKA  · CNES  · CNSA · ISRO · JAXA Other Private spaceflight · Space weather · Lagrangian point · Space and survival