104-444: A starship , starcraft , or interstellar spacecraft is a theoretical spacecraft designed for traveling between planetary systems . The term is mostly found in science fiction . Reference to a "star-ship" appears as early as 1882 in Oahspe: A New Bible . While NASA 's Voyager and Pioneer probes have traveled into local interstellar space, the purpose of these uncrewed craft
208-436: A Breakthrough Initiatives program, to develop a proof-of-concept fleet of small centimeter-sized light sail spacecraft named StarChip , capable of making the journey to Alpha Centauri , the nearest star system , at speeds of 20% and 15% of the speed of light , taking between 20 and 30 years to reach the star system, respectively, and about 4 years to notify Earth of a successful arrival. To travel between stars in
312-732: A launch vehicle (carrier rocket). On a sub-orbital spaceflight , a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth 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 from start or on orbit ( space stations ) only, whereas 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
416-452: A round trip from Earth to a distant star and back in an arbitrarily short time, as measured by clocks on Earth, by altering the metric along the path of their outbound trip. The metric of this form has significant difficulties because all known warp-drive spacetime theories violate various energy conditions . Nevertheless, an Alcubierre-type warp drive might be realized by exploiting certain experimentally verified quantum phenomena, such as
520-588: A 15.2 metres (50 ft) CanadaArm1 , an upgraded version of which is used on the International Space Station . The heat shield (or Thermal Protection System ) of the orbiter, used to protect it from extreme levels of heat during atmospheric reentry and the cold of space, was made up of different materials depending on weight and how much heating a particular area on the shuttle would receive during reentry, which ranged from over 2,900 °F (1,600 °C) to under 700 °F (370 °C). The orbiter
624-549: A blunt shape, do not usually contain much more fuel than needed, and they do not possess wings unlike spaceplanes . They are the simplest form of recoverable spacecraft, and so the most commonly used. The first such capsule was the Vostok capsule built by the Soviet Union, that carried the first person in space, Yuri Gagarin . Other examples include the Soyuz and Orion capsules, built by
728-420: A conjecture if it had), but there are good arguments in its favor based on quantum field theory. The conjecture does not prohibit faster-than-light travel. It just states that if a method to travel faster than light exists, and one tries to use it to build a time machine, something will go wrong: the energy accumulated will explode, or it will create a black hole." The Star Trek television series and films use
832-413: A general categorization of the kinds of starships: The Alcubierre drive is a speculative warp drive conjectured by Mexican physicist Miguel Alcubierre in a 1994 paper which has not been peer-reviewed . The paper suggests that space itself could be topographically warped to create a local region of spacetime wherein the region ahead of the "warp bubble" is compressed, allowed to resume normalcy within
936-485: A hypothetical concept with seemingly difficult problems, although the amount of energy required is no longer thought to be unobtainably large. Furthermore, Alexey Bobrick and Gianni Martire claim that, in principle, a class of subluminal, spherically symmetric warp drive spacetimes can be constructed based on physical principles presently known to humanity, such as positive energy. Using the ADM formalism of general relativity ,
1040-541: A liftoff thrust of 2,800,000 pounds-force (12 MN), which soon increased to 3,300,000 pounds-force (15 MN) per booster, and were fueled by a combination of PBAN and APCP , the Space Shuttle Orbiter , with 3 RS-25 engines that used a liquid oxygen / liquid hydrogen propellant combination, and the bright orange throwaway Space Shuttle external tank from which the RS-25 engines sourced their fuel. The orbiter
1144-585: A light beam within the warp bubble would still always move more quickly than the ship. Because objects within the bubble are not moving (locally) more quickly than light, the mathematical formulation of the Alcubierre metric is consistent with the conventional claims of the laws of relativity (namely, that an object with mass cannot attain or exceed the speed of light) and conventional relativistic effects such as time dilation would not apply as they would with conventional motion at near-light speeds. An extension of
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#17330847543611248-449: A means of superluminal travel. It only means that the actions required to change the metric and create the bubble must be taken beforehand by some observer whose forward light cone contains the entire trajectory of the bubble. For example, if one wanted to travel to Deneb (2,600 light-years away) and arrive less than 2,600 years in the future according to external clocks, it would be required that someone had already begun work on warping
1352-565: A planetary body are artificial satellites . To date, only a handful of interstellar probes , such as Pioneer 10 and 11 , Voyager 1 and 2 , and New Horizons , are on trajectories that leave the Solar System . Orbital spacecraft may be recoverable or not. Most are not. Recoverable spacecraft may be subdivided by a method of reentry to Earth into non-winged space capsules and winged spaceplanes . Recoverable spacecraft may be reusable (can be launched again or several times, like
1456-488: A professional scientific study examining advanced spacecraft propulsion systems. A common science-fiction device is to posit a faster-than-light propulsion system (such as warp drive ) or travel through hyperspace , although some posit starships as outfitted for centuries-long journeys of slower-than-light travel. Other designs posit a way to boost the ship to near-lightspeed, allowing relatively "quick" travel (i.e. decades, not centuries) to nearer stars. This results in
1560-471: A reasonable time using rocket -like technology requires very high effective exhaust velocity jet and enormous energy to power this, such as might be provided by fusion power or antimatter . There are very few scientific studies that investigate the issues in building a starship. Some examples of this include: The Bussard ramjet is an idea to use nuclear fusion of interstellar gas to provide propulsion. Examined in an October 1973 issue of Analog ,
1664-417: A rendezvous with Intelsat-901 on 25 February 2020. It will remain with the satellite until 2025 before the satellite is moved to a final graveyard orbit and the vehicle does a rendezvous with another satellite. The other one launched on an Ariane 5 rocket on 15 August 2020. A spacecraft astrionics system comprises different subsystems, depending on the mission profile. Spacecraft subsystems are mounted in
1768-551: A similar result could be achieved without tachyons by placing in advance some devices along the travel path and programming them to come into operation at preassigned moments and to operate in a preassigned manner. Some suggested methods avoid the problem of tachyonic motion, but would probably generate a naked singularity at the front of the bubble. Allen Everett and Thomas Roman comment on Krasnikov's finding ( Krasnikov tube ): [The finding] does not mean that Alcubierre bubbles, if it were possible to create them, could not be used as
1872-519: A single dark fluid , and which is expected to be testable by the Square Kilometre Array around 2030. Farnes found that Albert Einstein had explored the idea of gravitationally repulsive negative masses while developing the equations of general relativity , an idea which leads to a "beautiful" hypothesis where the cosmos has equal amounts of positive and negative qualities. Farnes' theory relies on negative masses that behave identically to
1976-636: A small spaceship across the Milky Way—an amount orders of magnitude greater than the estimated mass of the observable universe . Counterarguments to these apparent problems have also been offered, although the energy requirements still generally require a Type III civilization on the Kardashev scale . Chris Van Den Broeck of the Katholieke Universiteit Leuven in Belgium, in 1999, tried to address
2080-662: A spacecraft of their own, the CST-100 , commonly referred to as Starliner , but a crewed flight is yet to occur. China developed, but did not fly Shuguang , and is currently using Shenzhou (its first crewed mission was in 2003). Except for the Space Shuttle and the Buran spaceplane of the Soviet Union, the latter of which only ever had one uncrewed test flight, all of the recoverable crewed orbital spacecraft were space capsules . The International Space Station , crewed since November 2000,
2184-402: A warp bubble is formed in a previously flat space. Moreover, according to Serguei Krasnikov , generating a bubble in a previously flat space for a one-way faster-than-light trip requires forcing the exotic matter to move at local faster-than-light speeds, something that would require the existence of tachyons , although Krasnikov also notes that when the spacetime is not flat from the outset,
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#17330847543612288-491: Is a solution of the field equation of general relativity. Metrics in ADM form are adapted to a certain family of inertial observers, but these observers are not really physically distinguished from other such families. Alcubierre interpreted his "warp bubble" in terms of a contraction of space ahead of the bubble and an expansion behind, but this interpretation could be misleading, since the contraction and expansion actually refer to
2392-488: Is a buildup of vacuum fluctuations on the border of the region of spacetime where time travel would first become possible, causing the energy density to become high enough to destroy the system that would otherwise become a time machine. Some results in semiclassical gravity appear to support the conjecture, including a calculation dealing specifically with quantum effects in warp-drive spacetimes that suggested that warp bubbles would be semiclassically unstable, but ultimately
2496-645: Is a joint venture between Russia, the United States, Canada and several other countries. Uncrewed spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input; they may be remote controlled , remote guided or even autonomous , meaning they have a pre-programmed list of operations, which they will execute unless otherwise instructed. Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and lower risk factors. In addition, some planetary destinations such as Venus or
2600-406: Is a speculative warp drive idea according to which a spacecraft could achieve apparent faster-than-light travel by contracting space in front of it and expanding space behind it, under the assumption that a configurable energy-density field lower than that of vacuum (that is, negative mass ) could be created. Proposed by theoretical physicist Miguel Alcubierre in 1994, the Alcubierre drive
2704-443: Is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder ; it creates a communication channel between a source transmitter and a receiver at different locations on Earth . Communications satellites are used for television , telephone , radio , internet , and military applications. Many communications satellites are in geostationary orbit 22,300 miles (35,900 km) above
2808-450: Is based on a solution of Einstein's field equations . Since those solutions are metric tensors , the Alcubierre drive is also referred to as Alcubierre metric . Objects cannot accelerate to the speed of light within normal spacetime ; instead, the Alcubierre drive shifts space around an object so that the object would arrive at its destination more quickly than light would in normal space without breaking any physical laws . Although
2912-402: Is not yet known. Pfenning and Allen Everett of Tufts hold that a warp bubble traveling at 10-times the speed of light must have a wall thickness of no more than 10 meters—close to the limiting Planck length , 1.6 × 10 meters. In Alcubierre's original calculations, a bubble macroscopically large enough to enclose a ship of 200 meters would require a total amount of exotic matter greater than
3016-447: Is physically meaningful. Coule further argues that an analogous objection will apply to any proposed method of constructing an Alcubierre drive. An article by José Natário (2002) argues that crew members could not control, steer or stop the ship in its warp bubble because the ship could not send signals to the front of the bubble. A 2009 article by Carlos Barceló, Stefano Finazzi, and Stefano Liberati uses quantum theory to argue that
3120-525: Is physically possible with exotic matter . With regard to certain specific effects of special relativity, such as Lorentz contraction and time dilation , the Alcubierre metric has some apparently peculiar aspects. In particular, Alcubierre has shown that a ship using an Alcubierre drive travels on a free-fall geodesic even while the warp bubble is accelerating: its crew would be in free fall while accelerating without experiencing accelerational g-forces . Enormous tidal forces , however, would be present near
3224-519: 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 1940s there were several test launches of the V-2 rocket , some of which reached altitudes well over 100 km. As of 2016, only three nations have flown crewed spacecraft: USSR/Russia, USA, and China. The first crewed spacecraft
Starship - Misplaced Pages Continue
3328-608: Is to be replaced by expendable rockets such as the Space Launch System and ULA 's Vulcan rocket, as well as the commercial launch vehicles. 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 built a successor SpaceShipTwo . A fleet of SpaceShipTwos operated by Virgin Galactic
3432-438: Is what Alcubierre did in building his metric. This practice means that the solution can violate various energy conditions and require exotic matter . The need for exotic matter raises questions about whether one can distribute the matter in an initial spacetime that lacks a warp bubble in such a way that the bubble is created at a later time, although some physicists have proposed models of dynamical warp-drive spacetimes in which
3536-484: The Casimir effect , that lead to stress–energy tensors that also violate the energy conditions, such as negative mass–energy , when described in the context of the quantum field theories. If certain quantum inequalities conjectured by Ford and Roman hold, the energy requirements for some warp drives may be unfeasibly large as well as negative. For example, the energy equivalent of −10 kg might be required to transport
3640-505: The Casimir vacuum between parallel plates could fulfill the negative-energy requirement for the Alcubierre drive. Another possible issue is that, although the Alcubierre metric is consistent with Einstein's equations, general relativity does not incorporate quantum mechanics . Some physicists have presented arguments to suggest that a theory of quantum gravity (which would incorporate both theories) would eliminate those solutions in general relativity that allow for backward time travel (see
3744-541: The Deep Space Network . A space telescope or space observatory is a telescope in outer space used to observe astronomical objects. Space telescopes avoid the filtering and distortion of electromagnetic radiation which they observe, and avoid light pollution which ground-based observatories encounter. They are divided into two types: satellites which map the entire sky ( astronomical survey ), and satellites which focus on selected astronomical objects or parts of
3848-520: The Enzmann Starship proposed using a 12,000-ton ball of frozen deuterium to power pulse propulsion units. Twice as long as the Empire State Building is tall and assembled in-orbit, the proposed spacecraft would be part of a larger project preceded by interstellar probes and telescopic observation of target star systems. The NASA Breakthrough Propulsion Physics Program (1996–2002) was
3952-409: The International Space Station and Tiangong space station. Some spacecrafts can operate as both a crewed and uncrewed spacecraft. For example, the Buran spaceplane could operate autonomously but also had manual controls, though it never flew with crew onboard. Other dual crewed/uncrewed spacecrafts include: SpaceX Dragon 2 , Dream Chaser , and Tianzhou . A communications satellite
4056-440: The International Space Station : Russian Progress , American SpaceX Dragon 2 and Cygnus . Chinese Tianzhou is used to supply Tiangong space station . Space probes are robotic spacecraft that are sent to explore deep space, or astronomical bodies other than Earth. They are distinguished from landers by the fact that they work in open space, not on planetary surfaces or in planetary atmospheres. Being robotic eliminates
4160-820: The SpaceX Dragon and the Space Shuttle orbiters ) or expendable (like the Soyuz ). In recent years, more space agencies are tending towards reusable spacecraft. Humanity has achieved space flight, but only a few nations have the technology for orbital launches : Russia ( Roscosmos ), the United States ( NASA ), the member states of the European Space Agency , Japan ( JAXA ), China ( CNSA ), India ( ISRO ), Taiwan ( TSA ), Israel ( ISA ), Iran ( ISA ), and North Korea ( NADA ). In addition, several private companies have developed or are developing
4264-850: The Voskhod , Soyuz , flown uncrewed as Zond/L1 , L3 , TKS , and the Salyut and Mir crewed space stations . Other American crewed spacecraft include the Gemini spacecraft , the Apollo spacecraft including the Apollo Lunar Module , the Skylab space station, the Space Shuttle with undetached European Spacelab and private US Spacehab space stations-modules, and the SpaceX Crew Dragon configuration of their Dragon 2 . US company Boeing also developed and flown
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4368-461: The chronology protection conjecture ) and thus make the Alcubierre drive invalid. In 1994, Miguel Alcubierre proposed a method for changing the geometry of space by creating a wave that would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would then ride this wave inside a region of flat space, known as a warp bubble , and would not move within this bubble but instead be carried along as
4472-659: The dissolution of the USSR , prevented any further flights of Buran. The Space Shuttle was subsequently modified to allow for autonomous re-entry in case of necessity. Per the Vision for Space Exploration , the Space Shuttle was retired in 2011 mainly due 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 SpaceX 's SpaceX Dragon 2 and Boeing 's CST-100 Starliner . Dragon 2's first crewed flight occurred on May 30, 2020. The Shuttle's heavy cargo transport role
4576-528: The equator , so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit , where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by
4680-436: The satellite 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 . Alcubierre drive#Difficulties The Alcubierre drive ( [alkuˈβjere] )
4784-422: The spacetime is described by a foliation of space-like hypersurfaces of constant coordinate time t , with the metric taking the following general form: where The particular form that Alcubierre studied is defined by: where with arbitrary parameters R > 0 and σ > 0 . Alcubierre's specific form of the metric can thus be written: With this particular form of the metric, it can be shown that
4888-435: The weak energy condition , as well as both the strong and dominant energy conditions. Krasnikov proposed that if tachyonic matter cannot be found or used, then a solution might be to arrange for masses along the path of the vessel to be set in motion in such a way that the required field was produced. But in this case, the Alcubierre drive vessel can only travel routes that, like a railroad, have first been equipped with
4992-485: The "throat" of a wormhole ) is thought to be impractical. According to writer Robert Low, within the context of general relativity it is impossible to construct a warp drive in the absence of exotic matter. Astrophysicist Jamie Farnes from the University of Oxford has proposed a theory, published in the peer-reviewed scientific journal Astronomy & Astrophysics , that unifies dark energy and dark matter into
5096-532: The Alcubierre drive at faster-than-light velocities is impossible mostly because extremely high temperatures caused by Hawking radiation would destroy anything inside the bubble at superluminal velocities and destabilize the bubble itself; the article also argues that these problems are absent if the bubble velocity is subluminal, although the drive still requires exotic matter. Brendan McMonigal, Geraint F. Lewis , and Philip O'Byrne have argued that were an Alcubierre-driven ship to decelerate from superluminal speed,
5200-444: The Alcubierre metric that eliminates the expansion of the volume elements and instead relies on the change in distances along the direction of travel is that of mathematician José Natário. In his metric, spacetime contracts towards the prow of the ship and expands in the direction perpendicular to the motion, meaning that the bubble actually "slides" through space, roughly speaking by "pushing space aside". The Alcubierre drive remains
5304-840: The American Orbiting Astronomical Observatory , OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971. Space telescopes avoid the filtering and distortion ( scintillation ) of electromagnetic radiation which they observe, and avoid light pollution which ground-based observatories encounter. The best-known examples are Hubble Space Telescope and James Webb Space Telescope . Cargo spacecraft are designed to carry cargo , possibly to support space stations ' operation by transporting food, propellant and other supplies. Automated cargo spacecraft have been used since 1978 and have serviced Salyut 6 , Salyut 7 , Mir ,
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#17330847543615408-518: The CEO of SpaceX, estimated in a tweet that 8 launches would be needed to completely refuel a Starship in low Earth orbit , extrapolating this from Starship's payload to orbit and how much fuel a fully fueled Starship contains. To land on bodies without an atmosphere, such as the Moon, Starship will fire its engines and thrusters to slow down. The Mission Extension Vehicle is a robotic spacecraft designed to prolong
5512-421: The Moon, Mars, and potentially beyond. It is intended to enable long duration interplanetary flights for a crew of up to 100 people. It will also be capable of point-to-point transport on Earth, enabling travel to anywhere in the world in less than an hour. Furthermore, the spacecraft will be used to refuel other Starship vehicles to allow them to reach higher orbits to and other space destinations. Elon Musk ,
5616-494: The Solar System , these are Voyager 1 , Voyager 2 , Pioneer 10 , Pioneer 11 , and New Horizons . The identical Voyager probes , weighing 721.9 kilograms (1,592 lb), were launched in 1977 to take advantage of a rare alignment of Jupiter , Saturn , Uranus and Neptune that would allow a spacecraft to visit all four planets in one mission, and get to each destination faster by using gravity assist . In fact,
5720-508: The Soviet Union and NASA , respectively. Spaceplanes are spacecraft that are built in the shape of, and function as, airplanes . The first example of such was the North American X-15 spaceplane, which conducted two crewed flights which reached an altitude of over 100 kilometres (62 mi) in the 1960s. This first reusable spacecraft was air-launched on a suborbital trajectory on July 19, 1963. The first reusable orbital spaceplane
5824-544: The Sputnik launch was a single event, it marked the start of the Space Age . Apart from its value as a technological first, Sputnik 1 also helped to identify the upper atmospheric layer 's density, by measuring the satellite's orbital changes. It also provided data on radio -signal distribution in the ionosphere . Pressurized nitrogen in the satellite's false body provided the first opportunity for meteoroid detection. Sputnik 1
5928-514: The Sun as of August 2023. NASA provides real time data of their distances and data from the probe’s cosmic ray detectors. Because of the probe’s declining power output and degradation of the RTGs over time, NASA has had to shut down certain instruments to conserve power. The probes may still have some scientific instruments on until the mid-2020s or perhaps the 2030s. After 2036, they will both be out of range of
6032-511: The back of a Boeing 747 SCA and gliding to deadstick landings at Edwards AFB, California . The first Space Shuttle to fly into space was Columbia , followed by Challenger , Discovery , Atlantis , and Endeavour . Endeavour was built to replace Challenger when it was lost in January 1986. Columbia broke up during reentry in February 2003. The first autonomous reusable spaceplane
6136-419: The bubble moving toward Vega with a superluminal velocity would appear; such arrangements will always take more than 25 years. Coule has argued that schemes, such as the one proposed by Alcubierre, are infeasible because matter placed en route of the intended path of a craft must be placed at superluminal speed—that constructing an Alcubierre drive requires an Alcubierre drive even if the metric that allows it
6240-507: The bubble, and then rapidly expanded behind the bubble creating an effect that results in apparent FTL travel, all in a manner consistent with the Einstein field equations of general relativity and without the introduction of wormholes. However, the actual construction of such a drive would face other serious theoretical difficulties . There are widely known vessels in various science fiction franchises. The most prominent cultural use and one of
6344-454: The conjecture can only be decided by a full theory of quantum gravity . Alcubierre briefly discusses some of these issues in a series of lecture slides posted online, where he writes: "beware: in relativity, any method to travel faster than light can in principle be used to travel back in time (a time machine)". In the next slide, he brings up the chronology protection conjecture and writes: "The conjecture has not been proven (it wouldn't be
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#17330847543616448-407: The context of general relativity , allows a warp bubble to appear in previously flat spacetime and move away at effectively faster-than-light speed. The interior of the bubble is an inertial reference frame and inhabitants experience no proper acceleration. This method of transport does not involve objects in motion at faster-than-light speeds with respect to the contents of the warp bubble; that is,
6552-510: The curve of the Earth. The purpose of communications satellites is to relay the signal around the curve of the Earth allowing communication between widely separated geographical points. Communications satellites use a wide range of radio and microwave frequencies . To avoid signal interference, international organizations have regulations for which frequency ranges or "bands" certain organizations are allowed to use. This allocation of bands minimizes
6656-480: The different orbiters had differing weights and thus payloads, with Columbia being the heaviest orbiter, Challenger being lighter than Columbia but still heavier than the other three. The orbiter structure was mostly composed of aluminium alloy. The orbiter had seven seats for crew members, though on STS-61-A the launch took place with 8 crew onboard. The orbiters had 4.6 metres (15 ft) wide by 18 metres (59 ft) long payload bays and also were equipped with
6760-631: The earliest common uses of the term starship was in Star Trek: The Original Series . (This list is not exhaustive.) Spacecraft 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
6864-446: The edges of the flat-space volume because of the large space curvature there, but a suitable specification of the metric would keep the tidal forces very small within the volume occupied by the ship. The original warp-drive metric and simple variants of it happen to have the ADM form , which is often used in discussing the initial-value formulation of general relativity. This might explain the widespread misconception that this spacetime
6968-466: The energy density measured by observers whose 4-velocity is normal to the hypersurfaces is given by: where g is the determinant of the metric tensor . Thus, because the energy density is negative, one needs exotic matter to travel more quickly than the speed of light. The existence of exotic matter is not theoretically ruled out; however, generating and sustaining enough exotic matter to perform feats such as faster-than-light travel (and to keep open
7072-429: The experiment, saying: "from my understanding there is no way it can be done, probably not for centuries if at all". In 2021, physicist Erik Lentz described a way warp drives sourced from known and familiar purely positive energy could exist—warp bubbles based on superluminal self-reinforcing "soliton" waves. The claim is controversial, with other physicists arguing that all physically reasonable warp drives violate
7176-405: The extremely thin wall of the warp bubble, so the energy is focused in a larger volume, but the overall peak energy density is actually smaller. In a flat 2D representation, the ring of positive and negative energy, initially very thin, becomes a larger, fuzzy torus (donut shape). However, as this less energetic warp bubble also thickens toward the interior region, it leaves less flat space to house
7280-410: The general spacecraft categories. This is a list of these spacecraft. Starship is a spacecraft and second stage under development by American aerospace company SpaceX . Stacked atop its booster, Super Heavy , it composes the identically named Starship super heavy-lift space vehicle . The spacecraft is designed to transport both crew and cargo to a variety of destinations, including Earth orbit,
7384-426: The life on another spacecraft. It works by docking to its target spacecraft, then correcting its orientation or orbit. This also allows it to rescue a satellite which is in the wrong orbit by using its own fuel to move its target to the correct orbit. The project is currently managed by Northrop Grumman Innovation Systems. As of 2023, 2 have been launched. The first launched on a Proton rocket on 9 October 2019, and did
7488-541: The mass of the observable universe, and straining the exotic matter to an extremely thin band of 10 meters is considered impractical. Similar constraints apply to Krasnikov's superluminal subway . Chris Van den Broeck constructed a modification of Alcubierre's model that requires much less exotic matter but places the ship in a curved spacetime "bottle" whose neck is about 10 meters. Calculations by physicist Allen Everett show that warp bubbles could be used to create closed timelike curves in general relativity, meaning that
7592-549: The metric proposed by Alcubierre is consistent with the Einstein field equations, construction of such a drive is not necessarily possible. The proposed mechanism of the Alcubierre drive implies a negative energy density and therefore requires exotic matter or manipulation of dark energy . If exotic matter with the correct properties cannot exist, then the drive cannot be constructed. At the close of his original article, however, Alcubierre argued (following an argument developed by physicists analyzing traversable wormholes ) that
7696-406: The necessary infrastructure. The pilot inside the bubble is causally disconnected from its walls and cannot carry out any action outside the bubble: the bubble cannot be used for the first trip to a distant star because the pilot cannot place infrastructure ahead of the bubble while "in transit". For example, traveling to Vega (which is 25 light-years from Earth) requires arranging everything so that
7800-405: The necessary total amount of negative mass to a few milligrams. Van Den Broeck detailed this by saying that the total energy can be reduced dramatically by keeping the surface area of the warp bubble itself microscopically small, while at the same time expanding the spatial volume inside the bubble. However, Van Den Broeck concludes that the energy densities required are still unachievable, as are
7904-621: The need for expensive, heavy life support systems (the Apollo crewed Moon landings required the use of the Saturn V rocket that cost over a billion dollars per launch, adjusted for inflation) and so allows for lighter, less expensive rockets. Space probes have visited every planet in the Solar System and Pluto , and the Parker Solar Probe has an orbit that, at its closest point, is in the Sun's chromosphere . There are five space probes that are escaping
8008-406: The particles that its bubble had gathered in transit would be released in energetic outbursts akin to the infinitely-blueshifted radiation hypothesized to occur at the inner event horizon of a Kerr black hole ; forward-facing particles would thereby be energetic enough to destroy anything at the destination directly in front of the ship. The amount of negative energy required for such a propulsion
8112-505: The physics of the Alcubierre drive, providing a natural solution for the current "crisis in cosmology" due to a time-variable Hubble parameter . As Farnes' theory allows a positive mass (i.e. a ship) to reach a speed equal to the speed of light, it has been dubbed "controversial". If the theory is correct, which has been highly debated in the scientific literature, it would explain dark energy, dark matter, allow closed timelike curves (see time travel ), and suggest that an Alcubierre drive
8216-452: The potential issues. By contracting the 3+1-dimensional surface area of the bubble being transported by the drive, while at the same time expanding the three-dimensional volume contained inside, Van Den Broeck was able to reduce the total energy needed to transport small atoms to less than three solar masses . Later in 2003, by slightly modifying the Van den Broeck metric, Serguei Krasnikov reduced
8320-425: The region itself moves due to the actions of the drive. The local velocity relative to the deformed spacetime would be subluminal, but the speed at which a spacecraft could move would be superluminal, thereby rendering possible interstellar flight, such as a visit to Proxima Centauri within a few days. The Alcubierre metric defines the warp-drive spacetime . It is a Lorentzian manifold that, if interpreted in
8424-470: The relative motion of nearby members of the family of ADM observers. In general relativity, one often first specifies a plausible distribution of matter and energy, and then finds the geometry of the spacetime associated with it; but it is also possible to run the Einstein field equations in the other direction, first specifying a metric and then finding the energy–momentum tensor associated with it, and this
8528-471: The risk of signal interference. Cargo or resupply spacecraft are robotic spacecraft that are designed specifically to carry cargo , possibly to support space stations ' operation by transporting food, propellant and other supplies. Automated cargo spacecraft have been used since 1978 and have serviced Salyut 6 , Salyut 7 , Mir , the International Space Station and Tiangong space station. As of 2023, three different cargo spacecraft are used to supply
8632-513: The rocket that launched the probes (the Titan IIIE ) could not even send the probes to the orbit of Saturn , yet Voyager 1 is travelling at roughly 17 km/s (11 mi/s) and Voyager 2 moves at about 15 km/s (9.3 mi/s) kilometres per second as of 2023. In 2012, Voyager 1 exited the heliosphere, followed by Voyager 2 in 2018. Voyager 1 actually launched 16 days after Voyager 2 but it reached Jupiter sooner because Voyager 2
8736-454: The same way as a spaceship, as they coexist with numerous micro-organisms, and these micro-organisms are also hard to contain within a spaceship or spacesuit. Multiple space probes were sent to study Moon, the planets, the Sun, multiple small Solar System bodies (comets and asteroids). Special class of uncrewed spacecraft is space telescopes , a telescope in outer space used to observe astronomical objects. The first operational telescopes were
8840-504: The shuttle was a rather dangerous system, with fragile heat shielding tiles, some being so fragile that one could easily scrape it off by hand, often having been damaged in many flights. After 30 years in service from 1981 to 2011 and 135 flights, the shuttle was retired from service due to the cost of maintaining the shuttles, and the 3 remaining orbiters (the other two were destroyed in accidents) were prepared to be displayed in museums. Some spacecraft do not fit particularly well into any of
8944-583: The sky and beyond. Space telescopes are distinct from Earth imaging satellites , which point toward Earth for satellite imaging , applied for weather analysis , espionage , and other types of information gathering . A lander is a type of spacecraft that makes a soft landing on the surface of an astronomical body other than Earth . Some landers, such as Philae and the Apollo Lunar Module , land entirely by using their fuel supply, however many landers (and landings of spacecraft on Earth ) use aerobraking , especially for more distant destinations. This involves
9048-608: The small size (a few orders of magnitude above the Planck scale ) of the spacetime structures needed. In 2012, physicist Harold White and collaborators announced that modifying the geometry of exotic matter could reduce the mass–energy requirements for a macroscopic space ship from the equivalent of the planet Jupiter to that of the Voyager 1 spacecraft (c. 700 kg) or less, and stated their intent to perform small-scale experiments in constructing warp fields. White proposed to thicken
9152-411: The space from Earth to Deneb at least 2,600 years ago: A spaceship appropriately located with respect to the bubble trajectory could then choose to enter the bubble, rather like a passenger catching a passing trolley car, and thus make the superluminal journey ... as Krasnikov points out, causality considerations do not prevent the crew of a spaceship from arranging, by their own actions, to complete
9256-415: The spacecraft using a fuel burn to change its trajectory so it will pass through a planet (or a moon's) atmosphere. Drag caused by the spacecraft hitting the atmosphere enables it to slow down without using fuel, however this generates very high temperatures and so adds a requirement for a heat shield of some sort. Space capsules are a type of spacecraft that can return from space at least once. They have
9360-416: The spacecraft, which has to be smaller. Furthermore, if the intensity of the space warp can be oscillated over time, the energy required is reduced even more. According to White, a modified Michelson–Morley interferometer could test the idea: one of the legs of the interferometer would appear to have a slightly different length when the test devices were energised. Alcubierre has expressed skepticism about
9464-682: The technology for orbital launches independently from government agencies. The most prominent examples of such companies are SpaceX and Blue Origin . A German V-2 became the first spacecraft when it reached an altitude of 189 km in June 1944 in Peenemünde , Germany. Sputnik 1 was the first artificial satellite . It was launched into an elliptical low Earth orbit (LEO) by the Soviet Union on 4 October 1957. The launch ushered in new political, military, technological, and scientific developments; while
9568-404: The term "warp drive" to describe their method of faster-than-light travel. Neither the Alcubierre theory, nor anything similar, existed when the series was conceived—the term "warp drive" and general concept originated with John W. Campbell 's 1931 science fiction novel Islands of Space . Alcubierre stated in an email to William Shatner that his theory was directly inspired by the term used in
9672-461: The theory predicts that they could be used for backwards time travel . While it is possible that the fundamental laws of physics might allow closed timelike curves, the chronology protection conjecture hypothesizes that in all cases where the classical theory of general relativity allows them, quantum effects would intervene to eliminate the possibility, making these spacetimes impossible to realize. A possible type of effect that would accomplish this
9776-420: The vicinity of Jupiter are too hostile for human survival. Outer planets such as Saturn , Uranus , and Neptune are too distant to reach with current crewed spaceflight technology, so telerobotic probes are the only way to explore them. Telerobotics also allows exploration of regions that are vulnerable to contamination by Earth micro-organisms since spacecraft can be sterilized. Humans can not be sterilized in
9880-503: Was Vostok 1 , which carried Soviet cosmonaut Yuri Gagarin into space in 1961, and completed a full Earth orbit. There were five other crewed missions which used a Vostok spacecraft . The second crewed spacecraft was named Freedom 7 , and it performed a sub-orbital spaceflight in 1961 carrying American astronaut Alan Shepard to an altitude of just over 187 kilometers (116 mi). There were five other crewed missions using Mercury spacecraft . Other Soviet crewed spacecraft include
9984-596: Was a spaceplane that was launched at NASA’s Kennedy Space Centre and landed mainly at the Shuttle Landing Facility , which is part of Kennedy Space Centre. A second launch site, Vandenberg Space Launch Complex 6 in California , was revamped so it could be used to launch the shuttles, but it was never used. The launch system could lift about 29 tonnes (64,000 lb) into an eastward Low Earth Orbit . Each orbiter weighed roughly 78 tonnes (172,000 lb), however
10088-453: Was due to expensive refurbishment costs and the external tank being expended. Once a landing had occurred, the SRBs and many parts of the orbiter had to be disassembled for inspection, which was long and arduous. Furthermore, the RS-25 engines had to be replaced every few flights. Each of the heat shielding tiles had to go in one specific area on the orbiter, increasing complexity more. Adding to this,
10192-660: Was launched during the International Geophysical Year from Site No.1/5 , at the 5th Tyuratam range, in Kazakh SSR (now at the Baikonur Cosmodrome ). The satellite travelled at 29,000 kilometres per hour (18,000 mph), taking 96.2 minutes to complete an orbit, and emitted radio signals at 20.005 and 40.002 MHz While Sputnik 1 was the first spacecraft to orbit the Earth, other human-made objects had previously reached an altitude of 100 km, which
10296-595: Was manually operated, though an autonomous landing system was added while the shuttle was still on service. It had an in orbit maneouvreing system known as the Orbital Manoeuvring System, which used the hypergolic propellants monomethylhydrazine (MMH) and dinitrogen tetroxide , which was used for orbital insertion, changes to orbits and the deorbit burn. Though the shuttle’s goals were to drastically decrease launch costs, it did not do so, ending up being much more expensive than similar expendable launchers. This
10400-439: Was planned to begin reusable private spaceflight carrying paying passengers in 2014, but was delayed after the crash of VSS Enterprise . The Space Shuttle is a retired reusable Low Earth Orbital launch system. It consisted of two reusable Solid Rocket Boosters that landed by parachute, were recovered at sea, and were the most powerful rocket motors ever made until they were superseded by those of NASA’s SLS rocket, with
10504-473: Was specifically interplanetary, and they are not predicted to reach another star system; Voyager 1 probe and Gliese 445 will pass one another within 1.6 light years in about 40,000 years. Several preliminary designs for starships have been undertaken through exploratory engineering , using feasibility studies with modern technology or technology thought likely to be available in the near future. In April 2016, scientists announced Breakthrough Starshot ,
10608-403: Was taking a longer route that allowed it to visit Uranus and Neptune, whereas Voyager 1 did not visit Uranus or Neptune, instead choosing to fly past Saturn’s satellite Titan . As of August 2023, Voyager 1 has passed 160 astronomical units , which means it is over 160 times farther from the Sun than Earth is. This makes it the farthest spacecraft from the Sun. Voyager 2 is 134 AU away from
10712-518: Was the Buran -class shuttle , launched by the USSR on November 15, 1988, although it made only one flight and this was uncrewed. 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
10816-560: Was the Space Shuttle orbiter . The first orbiter to fly in space, the Space Shuttle Columbia , 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. Enterprise was used only for approach and landing tests, launching from
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