Project Orion (nuclear propulsion)
Project Orion was a study of a spacecraft intended to be directly propelled by a series of explosions of atomic bombs behind the craft. Early versions of this vehicle were proposed to take off from the ground with significant associated nuclear fallout. Six tests were launched; the idea of rocket propulsion by combustion of explosive substance was first proposed by Russian explosives expert Nikolai Kibalchich in 1881, in 1891 similar ideas were developed independently by German engineer Hermann Ganswindt. General proposals of nuclear propulsion were first made by Stanislaw Ulam in 1946, preliminary calculations were made by F. Reines and Ulam in a Los Alamos memorandum dated 1947; the actual project, initiated in 1958, was led by Ted Taylor at General Atomics and physicist Freeman Dyson, who at Taylor's request took a year away from the Institute for Advanced Study in Princeton to work on the project. The Orion concept offered high thrust and high specific impulse, or propellant efficiency, at the same time.
The unprecedented extreme power requirements for doing so would be met by nuclear explosions, of such power relative to the vehicle's mass as to be survived only by using external detonations without attempting to contain them in internal structures. As a qualitative comparison, traditional chemical rockets—such as the Saturn V that took the Apollo program to the Moon—produce high thrust with low specific impulse, whereas electric ion engines produce a small amount of thrust efficiently. Orion would have offered performance greater than the most advanced conventional or nuclear rocket engines under consideration. Supporters of Project Orion felt that it had potential for cheap interplanetary travel, but it lost political approval over concerns with fallout from its propulsion; the Partial Test Ban Treaty of 1963 is acknowledged to have ended the project. However, from Project Longshot to Project Daedalus, Mini-Mag Orion, other proposals which reach engineering analysis at the level of considering thermal power dissipation, the principle of external nuclear pulse propulsion to maximize survivable power has remained common among serious concepts for interstellar flight without external power beaming and for high-performance interplanetary flight.
Such proposals have tended to modify the basic principle by envisioning equipment driving detonation of much smaller fission or fusion pellets, in contrast to Project Orion's larger nuclear pulse units based on less speculative technology. To Mars by A-Bomb: The Secret History of Project Orion was a 2003 BBC documentary film about the project; the Orion nuclear pulse drive combines a high exhaust velocity, from 19 to 31 km/s in typical interplanetary designs, with meganewtons of thrust. Many spacecraft propulsion drives can achieve one of these or the other, but nuclear pulse rockets are the only proposed technology that could meet the extreme power requirements to deliver both at once. Specific impulse measures how much thrust can be derived from a given mass of fuel, is a standard figure of merit for rocketry. For any rocket propulsion, since the kinetic energy of exhaust goes up with velocity squared, whereas the momentum and thrust go up with velocity linearly, obtaining a particular level of thrust requires far more power each time that exhaust velocity and Isp are much increased in a design goal.
The Orion concept detonates nuclear explosions externally at a rate of power release, beyond what nuclear reactors could survive internally with known materials and design. Since weight is no limitation, an Orion craft can be robust. An unmanned craft could tolerate large accelerations 100 g. A human-crewed Orion, must use some sort of damping system behind the pusher plate to smooth the near instantaneous acceleration to a level that humans can comfortably withstand – about 2 to 4 g; the high performance depends on the high exhaust velocity, in order to maximize the rocket's force for a given mass of propellant. The velocity of the plasma debris is proportional to the square root of the change in the temperature of the nuclear fireball. Since fireballs achieve ten million degrees Celsius or more in less than a millisecond, they create high velocities. However, a practical design must limit the destructive radius of the fireball; the diameter of the nuclear fireball is proportional to the square root of the bomb's explosive yield.
The shape of the bomb's reaction mass is critical to efficiency. The original project designed bombs with a reaction mass made of tungsten; the bomb's geometry and materials focused the X-rays and plasma from the core of nuclear explosive to hit the reaction mass. In effect each bomb would be a nuclear shaped charge. A bomb with a cylinder of reaction mass expands into a flat, disk-shaped wave of plasma when it explodes. A bomb with a disk-shaped reaction mass expands into a far more efficient cigar-shaped wave of plasma debris; the cigar shape focuses much of the plasma to impinge onto the pusher-plate. The maximum effective specific impulse, Isp, of an Orion nuclear pulse drive is equal to: I s p = C
The Pioneer program was a series of United States unmanned space missions that were designed for planetary exploration. There were a number of such missions in the program, but the most notable were Pioneer 10 and Pioneer 11, which explored the outer planets and left the solar system. Pioneer 10 and Pioneer 11 carry a golden plaque, depicting a man and a woman and information about the origin and the creators of the probes, should any extraterrestrials find them someday. Credit for naming the first probe has been attributed to Stephen A. Saliga, assigned to the Air Force Orientation Group, Wright-Patterson AFB, as chief designer of Air Force exhibits. While he was at a briefing, the spacecraft was described to him, as, a "lunar-orbiting vehicle, with an infrared scanning device." Saliga thought the title too long, lacked theme for an exhibit design. He suggested, "Pioneer", as the name of the probe, since "the Army had launched and orbited the Explorer satellite, their Public Information Office was identifying the Army, as,'Pioneers in Space,'" and, by adopting the name, the Air Force would "make a'quantum jump' as to who the'Pioneers' in space.'"
The earliest missions were attempts to achieve Earth's escape velocity to show it was feasible and study the Moon. This included the first launch by NASA, formed from the old NACA; these missions were carried out by Army. Most missions here are listed with their most recognised name, alternate names after in parenthesis. Pioneer 0 – Lunar orbiter, destroyed August 17, 1958 Pioneer 1 – Lunar orbiter, missed Moon October 11, 1958 Pioneer 2 – Lunar orbiter, reentry November 8, 1958 Pioneer P-1, Launch vehicle lost September 24, 1959 Pioneer P-3 – Lunar probe, lost in launcher failure November 26, 1959 Pioneer 5 – interplanetary space between Earth and Venus, launched March 11, 1960 Pioneer P-30 – Lunar probe, failed to achieve lunar orbit September 25, 1960 Pioneer P-31 – Lunar probe, lost in upper stage failure December 15, 1960 Pioneer 3 – Lunar flyby, missed Moon due to launcher failure December 6, 1958 Pioneer 4 – Lunar flyby, achieved Earth escape velocity, launched March 3, 1959 Five years after the early Able space probe missions ended, NASA Ames Research Center used the Pioneer name for a new series of missions aimed at the inner Solar System, before the bold flyby missions to Jupiter and Saturn.
While successful, the missions returned much poorer images than the Voyager program probes would five years later. In 1978, the end of the program saw a return to the inner Solar System, with the Pioneer Venus Orbiter and Multiprobe, this time using orbital insertion rather than flyby missions; the new missions were numbered beginning with Pioneer 6. The spacecraft in Pioneer missions 6, 7, 8, 9 comprised a new interplanetary space weather network: Pioneer 6 – launched December 1965 Pioneer 7 – launched August 1966 Pioneer 8 – launched December 1967 Pioneer 9 – launched November 1968 Pioneer E – lost in launcher failure August 1969Pioneer 6 and Pioneer 9 are in solar orbits with 0.8 AU distance to the Sun. Their orbital periods are therefore shorter than Earth's. Pioneer 7 and Pioneer 8 are in solar orbits with 1.1 AU distance to the Sun. Their orbital periods are therefore longer than Earth's. Since the probes' orbital periods differ from that of the Earth, from time to time, they face a side of the Sun that cannot be seen from Earth.
The probes can sense parts of the Sun several days before the Sun's rotation reveals it to ground-based Earth orbiting observatories. Pioneer 10 – Jupiter, interstellar medium, launched March 1972 Pioneer 11 – Jupiter, interstellar medium, launched April 1973 Pioneer H – identical to Pioneers 10 and 11. Proposed was not built. Pioneer Venus Orbiter – launched May 1978 Pioneer Venus Multiprobe – launched August 1978 Pioneer Venus Probe Bus – transport vehicle and upper atmosphere probe Pioneer Venus Large Probe – 300 kg parachuted probe Pioneer Venus North Probe – 75 kg impactor probe Pioneer Venus Night Probe – 75 kg impactor probe Pioneer Venus Day Probe – 75 kg impactor probe Mariner program Pioneer anomaly Ranger program Surveyor program Timeline of Solar System exploration Voyager program Pioneer Program Page by NASA's Solar System Exploration Mark Wolverton's The Depths of Space online Thor Able – Encyclopedia Astronautica Space Technology Laboratories Documents Archive WebGL-based 3D artist's view of Pioneer @ SPACECRAFTS 3D
An interstellar probe is a space probe that has left—or is expected to leave—the Solar System and enter interstellar space, defined as the region beyond the heliopause. It refers to probes capable of reaching other star systems. There are five interstellar probes: Voyager 2, Pioneer 10, Pioneer 11 and New Horizons; as of 2019, Voyager 1 and Voyager 2 are only probes to have reached interstellar space. The other three are on interstellar trajectories; the termination shock is the point in the heliosphere where the solar wind slows down to subsonic speed. Though the termination shock happens as close as 80–100 AU, the maximum extent of the region in which the Sun's gravitational field is dominant is thought to be at around 230,000 astronomical units; this point is close to Alpha Centauri, located 4.36 light years away. Although the probes will be under the influence of the Sun for a long time, their velocities far exceed the Sun's escape velocity, so they will leave forever. Interstellar space is defined as that which lies beyond a magnetic region that extends about 122 AU from the sun, as detected by Voyager 1, the equivalent region of influence surrounding other stars.
Voyager 1 entered interstellar space in 2012. Interstellar Probe is the name of a proposed NASA space probe intended to travel out 200 AU in 15 years, studied in 1999. In April 2016, scientists announced Breakthrough Starshot, 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 extrasolar star system, at speeds of 20% and 15% of the speed of light, taking between 20 and 30 years to reach the star system and about 4 years to notify Earth of a successful arrival. Planetary scientist G. Laughlin noted that with current technology a probe sent to Alpha Centauri would take 40,000 years to arrive, but expressed hope for new technology to be developed to make the trip within a human lifetime. On that timescale the stars move notably; as an example, in 40,000 years Ross 248 will be closer to Earth than Alpha Centauri. One technology, proposed to achieve higher speeds is an E-sail.
By harnessing solar wind, it might be possible to achieve 20-30 AU per year without using propellant. Voyager 1 is a space probe launched by NASA on September 5, 1977. At a distance of about 139.114 AU as of 31 March 2019, it is the farthest manmade object from Earth. It was estimated that Voyager 1 crossed the termination shock on December 15, 2004 at a distance of 94 AU from the Sun. At the end of 2011, Voyager 1 entered and discovered a stagnation region where charged particles streaming from the Sun slow and turn inward, the Solar System's magnetic field is doubled in strength as interstellar space appears to be applying pressure. Energetic particles originating in the Solar System declined by nearly half, while the detection of high-energy electrons from outside increases 100-fold; the inner edge of the stagnation region is located 113 astronomical units from the Sun. In 2013 it was thought Voyager 1 crossed the heliopause and entered interstellar space on August 25, 2012 at distance of 121 AU from the Sun, making it the first known human-manufactured object to do so.
As of 2017, the probe was moving with a relative velocity to the Sun of about 16.95 km/s. If it does not hit anything, Voyager 1 could reach the Oort cloud in about 300 years Voyager 2 crossed the heliopause and entered interstellar space on November 5, 2018, it had passed the termination shock into the heliosheath on October 30, 2007. As of 31 March 2019 Voyager 2 is at a distance of 114.45 AU from Earth. The probe was moving at a velocity of 3.25 AU/year relative to the Sun on its way to interstellar space in 2013. It's moving at a velocity of 15.4 km/s relative to the Sun as of December 2014. Voyager 2 is expected to provide the first direct measurements of the density and temperature of the interstellar plasma. New Horizons was launched directly into a hyperbolic escape trajectory, getting a gravitational assist from Jupiter en route. By March 7, 2008, New Horizons was traveling outward at 3.9 AU per year. It will, slow to an escape velocity of only 2.5 AU per year as it moves away from the Sun, so it will never catch up to either Voyager.
As of early 2011, it was traveling at 3.356 AU/year relative to the Sun. On July 14, 2015, it completed a flyby of Pluto at a distance of about 33 AU from the Sun. New Horizons is expected to encounter 2014 MU69 on January 2019, at about 43.4 AU from the Sun. The Heliosphere's termination shock was crossed by Voyager 1 at 94 astronomical units and Voyager 2 at 84 AU according to the IBEX mission. If New Horizons can reach the distance of 100 AU, it will be traveling at about 13 km/s, around 4 km/s slower than Voyager 1 at that distance; the last successful reception of telemetry from Pioneer 10 was on April 27, 2002, when it was at a distance of 80.22 AU, traveling at about 2.54 AU/year. Routine mission operations for Pioneer 11 were stopped September 30, 1995, when it was 6.5 billion km from Earth, traveling at about 2.4 AU/year. New Horizons' third stage, a STAR-48 booster, is on a similar escape trajectory out of the Solar System as New Horizons, but will pass millions of kilometers from Pluto.
It crossed Pluto's orbit in October 2015. The third stage rocket boosters for Pioneer 10, for Voyager 1 and 2 are on escape trajectories out of the Solar System. In the early 2000s many new large planetary bod
An orbital spaceflight is a spaceflight in which a spacecraft is placed on a trajectory where it could remain in space for at least one orbit. To do this around the Earth, it must be on a free trajectory which has an altitude at perigee above 100 kilometers. To remain in orbit at this altitude requires an orbital speed of ~7.8 km/s. Orbital speed is slower for higher orbits, but attaining them requires greater delta-v. Due to atmospheric drag, the lowest altitude at which an object in a circular orbit can complete at least one full revolution without propulsion is 150 kilometres; the expression "orbital spaceflight" is used to distinguish from sub-orbital spaceflights, which are flights where the apogee of a spacecraft reaches space, but the perigee is too low. Orbital spaceflight from Earth has only been achieved by launch vehicles that use rocket engines for propulsion. To reach orbit, the rocket must impart to the payload a delta-v of about 9.3–10 km/s. This figure is for horizontal acceleration needed to reach orbital speed, but allows for atmospheric drag, gravity losses, gaining altitude.
The main proven technique involves launching nearly vertically for a few kilometers while performing a gravity turn, progressively flattening the trajectory out at an altitude of 170+ km and accelerating on a horizontal trajectory for a 5–8-minute burn until orbital velocity is achieved. 2–4 stages are needed to achieve the required delta-v. Most launches are by expendable launch systems; the Pegasus rocket for small satellites instead launches from an aircraft at an altitude of 12 km. There have been many proposed methods for achieving orbital spaceflight that have the potential of being much more affordable than rockets; some of these ideas such as the space elevator, rotovator, require new materials much stronger than any known. Other proposed ideas include ground accelerators such as launch loops, rocket assisted aircraft/spaceplanes such as Reaction Engines Skylon, scramjet powered spaceplanes, RBCC powered spaceplanes. Gun launch has been proposed for cargo. From 2015 SpaceX have demonstrated significant progress in their more incremental approach to reducing the cost of orbital spaceflight.
Their potential for cost reduction comes from pioneering propulsive landing with their reusable rocket booster stage as well as their Dragon capsule, but includes reuse of the other components such as the payload fairings and the use of 3D printing of a superalloy to construct more efficient rocket engines, such as their SuperDraco. The initial stages of these improvements could reduce the cost of an orbital launch by an order of magnitude. An object in orbit at an altitude of less than 200 km is considered unstable due to atmospheric drag. For a satellite to be in a stable orbit, 350 km is a more standard altitude for low Earth orbit. For example, on 1 February 1958 the Explorer 1 satellite was launched into an orbit with a perigee of 358 kilometers, it remained in orbit for more than 12 years before its atmospheric reentry over the Pacific Ocean on 31 March 1970. However, the exact behaviour of objects in orbit depends on altitude, their ballistic coefficient, details of space weather which can affect the height of the upper atmosphere.
There are three main'bands' of orbit around the Earth: low Earth orbit, medium Earth orbit and geostationary orbit. Due to orbital mechanics, orbits are in a particular fixed plane around the Earth, which coincides with the center of the Earth, may be tilted with respect to the equator; the Earth rotates about its axis within this orbit, the relative motion of the spacecraft and the movement of the Earth's surface determines the position that the spacecraft appears in the sky from the ground, which parts of the Earth are visible from the spacecraft. By dropping a vertical down to the Earth's surface it is possible to calculate a ground track that shows which part of the Earth a spacecraft is above, this is useful for helping to visualise the orbit. In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth—for example those in orbits around the Sun—an orbital maneuver is called a deep-space maneuver. Returning spacecraft have to find a way of slowing down as much as possible while still in higher atmospheric layers and avoid hitting the ground or burning up.
For many orbital space flights, initial deceleration is provided by the retrofiring of the craft's rocket engines, perturbing the orbit onto a suborbital trajectory. Many spacecraft in low-Earth orbit solve the problem of deceleration from orbital speeds through using atmospheric drag to provide initial deceleration. In all cases, once initial deceleration has lowered the orbital perigee into the mesosphere, all spacecraft lose most of the remaining speed, therefore kinetic energy, through the atmospheric drag effect of aerobraking. Intentional aerobraking is achieved by orienting the returning space craft so as to present the heat shields forward toward the atmosphere to protect against the high temperatures generated by atmospheri
Speed of light
The speed of light in vacuum denoted c, is a universal physical constant important in many areas of physics. Its exact value is 299,792,458 metres per second, it is exact because by international agreement a metre is defined as the length of the path travelled by light in vacuum during a time interval of 1/299792458 second. According to special relativity, c is the maximum speed at which all conventional matter and hence all known forms of information in the universe can travel. Though this speed is most associated with light, it is in fact the speed at which all massless particles and changes of the associated fields travel in vacuum; such particles and waves travel at c regardless of the motion of the source or the inertial reference frame of the observer. In the special and general theories of relativity, c interrelates space and time, appears in the famous equation of mass–energy equivalence E = mc2; the speed at which light propagates through transparent materials, such as glass or air, is less than c.
The ratio between c and the speed v at which light travels in a material is called the refractive index n of the material. For example, for visible light the refractive index of glass is around 1.5, meaning that light in glass travels at c / 1.5 ≈ 200,000 km/s. For many practical purposes and other electromagnetic waves will appear to propagate instantaneously, but for long distances and sensitive measurements, their finite speed has noticeable effects. In communicating with distant space probes, it can take minutes to hours for a message to get from Earth to the spacecraft, or vice versa; the light seen from stars left them many years ago, allowing the study of the history of the universe by looking at distant objects. The finite speed of light limits the theoretical maximum speed of computers, since information must be sent within the computer from chip to chip; the speed of light can be used with time of flight measurements to measure large distances to high precision. Ole Rømer first demonstrated in 1676 that light travels at a finite speed by studying the apparent motion of Jupiter's moon Io.
In 1865, James Clerk Maxwell proposed that light was an electromagnetic wave, therefore travelled at the speed c appearing in his theory of electromagnetism. In 1905, Albert Einstein postulated that the speed of light c with respect to any inertial frame is a constant and is independent of the motion of the light source, he explored the consequences of that postulate by deriving the theory of relativity and in doing so showed that the parameter c had relevance outside of the context of light and electromagnetism. After centuries of precise measurements, in 1975 the speed of light was known to be 299792458 m/s with a measurement uncertainty of 4 parts per billion. In 1983, the metre was redefined in the International System of Units as the distance travelled by light in vacuum in 1/299792458 of a second; the speed of light in vacuum is denoted by a lowercase c, for "constant" or the Latin celeritas. In 1856, Wilhelm Eduard Weber and Rudolf Kohlrausch had used c for a different constant shown to equal √2 times the speed of light in vacuum.
The symbol V was used as an alternative symbol for the speed of light, introduced by James Clerk Maxwell in 1865. In 1894, Paul Drude redefined c with its modern meaning. Einstein used V in his original German-language papers on special relativity in 1905, but in 1907 he switched to c, which by had become the standard symbol for the speed of light. Sometimes c is used for the speed of waves in any material medium, c0 for the speed of light in vacuum; this subscripted notation, endorsed in official SI literature, has the same form as other related constants: namely, μ0 for the vacuum permeability or magnetic constant, ε0 for the vacuum permittivity or electric constant, Z0 for the impedance of free space. This article uses c for the speed of light in vacuum. Since 1983, the metre has been defined in the International System of Units as the distance light travels in vacuum in 1⁄299792458 of a second; this definition fixes the speed of light in vacuum at 299,792,458 m/s. As a dimensional physical constant, the numerical value of c is different for different unit systems.
In branches of physics in which c appears such as in relativity, it is common to use systems of natural units of measurement or the geometrized unit system where c = 1. Using these units, c does not appear explicitly because multiplication or division by 1 does not affect the result; the speed at which light waves propagate in vacuum is independent both of the motion of the wave source and of the inertial frame of reference of the observer. This invariance of the speed of light was postulated by Einstein in 1905, after being motivated by Maxwell's theory of electromagnetism and the lack of evidence for the luminiferous aether, it is only possible to verify experimentally that the two-way speed of light is frame-independent, because it is impossible to measure the one-way speed of light without some convention as to how clocks at the source and at the detector should be synchronized. However
Cryonics is the low-temperature freezing of a human corpse, with the hope that resuscitation may be possible in the future. It is regarded with skepticism within the mainstream scientific community and has been characterized as quackery. Cryonics procedures can begin only after clinical death, cryonics "patients" are dead. Cryonics procedures ideally begin within minutes of death, use cryoprotectants to prevent ice formation during cryopreservation, it is unlikely that a corpse could be reanimated after undergoing vitrification, which causes damage to the brain including its neural networks. The first corpse to be frozen was that of Dr. James Bedford in 1967; as of 2014, about 250 bodies were cryopreserved in the United States, 1,500 people had made arrangements for cryopreservation after their legal death. Cryonic proponents go further than the mainstream consensus in saying that the brain does not have to be continuously active to survive or retain memory. Cryonics controversially states that a human survives within an inactive brain, badly damaged, provided that original encoding of memory and personality can, in theory, be adequately inferred and reconstituted from structure that remains.
Cryonicists argue that as long as brain structure remains intact, there is no fundamental barrier, given our current understanding of physical law, to recovering its information content. The cryonics' argument that death does not occur as long as brain structure remains intact and theoretically repairable has received some mainstream medical discussion in the context of the ethical concept of brain death and organ donation. Cryonics uses temperatures below −130 °C, called cryopreservation, in an attempt to preserve enough brain information to permit future revival of the cryopreserved person. Cryopreservation may be accomplished by freezing, freezing with cryoprotectant to reduce ice damage, or by vitrification to avoid ice damage. Using the best methods, cryopreservation of whole bodies or brains is damaging and irreversible with current technology. Cryonics requires future technology to repair or regenerate tissue, diseased, damaged, or missing. Brain repairs in particular will require analysis at the molecular level.
This far-future technology is assumed to be nanomedicine based on molecular nanotechnology. Biological repair methods or mind uploading have been proposed. Costs can include payment for medical personnel to be on call for death, transportation in dry ice to a preservation facility, payment into a trust fund intended to cover indefinite storage in liquid nitrogen and future revival costs; as of 2011, U. S. cryopreservation costs can range from $28,000 to $200,000, are financed via life insurance. KrioRus, which stores bodies communally in large dewars, charges $12,000 to $36,000 for the procedure; some patients opt to have only their brain cryopreserved, rather than their whole body. As of 2014, about 250 corpses have been cryogenically preserved in the U. S. and around 1,500 people have signed up to have their remains preserved. As of 2016, four facilities exist in the world to retain cryopreserved bodies: three in the U. S. and one in Russia. Long-term preservation of biological tissue can be achieved by cooling to temperatures below −130 °C.
Immersion in liquid nitrogen at a temperature of −196 °C is used for convenience. Low temperature preservation of tissue is called cryopreservation. Contrary to popular belief, water that freezes during cryopreservation is water outside cells, not water inside cells. Cells don't burst during freezing, but instead become dehydrated and compressed between ice crystals that surround them. Intracellular ice formation occurs only if the rate of freezing is faster than the rate of osmotic loss of water to the extracellular space. Without cryoprotectants, cell shrinkage and high salt concentrations during freezing prevent frozen cells from functioning again after thawing. In tissues and organs, ice crystals can disrupt connections between cells that are necessary for organs to function; the difficulties of recovering large animals and their individual organs from a frozen state have been long known. Attempts to recover frozen mammals by rewarming them were abandoned by 1957. At present, only cells and some small organs can be reversibly cryopreserved.
When used at high concentrations, cryoprotectants can stop ice formation completely. Cooling and solidification without crystal formation is called vitrification; the first cryoprotectant solutions able to vitrify at slow cooling rates while still being compatible with whole organ survival were developed in the late 1990s by cryobiologists Gregory Fahy and Brian Wowk for the purpose of banking transplantable organs. This has allowed animal brains to be vitrified, warmed back up, examined for ice damage using light and electron microscopy. No ice crystal damage was found. Large vitrified organs tend to develop fractures during cooling, a problem worsened by the large tissue masses and low temperatures of cryonics; the use of vitrification rather than freezing for cryonics was anticipated in 1986, when K. Eric Drexler proposed a technique called fixation and vitrification, anticipating reversal by molecular nanotechnology. In 2016, Robert L. McIntyre and Gregory Fahy at the cryobiology research company 21st Century Medicine, Inc. won the Small Animal Brain Preservation Prize of the Brain Preservation Foundation by demonstrating to the satisfaction of neuroscientist judges that a particular implementation of fixation and vitrification called aldehyde-stabilized cryopreservation coul
Aerospace is the human effort in science and business to fly in the atmosphere of Earth and surrounding space. Aerospace organizations research, manufacture, operate, or maintain aircraft or spacecraft. Aerospace activity is diverse, with a multitude of commercial and military applications. Aerospace is not the same as airspace, the physical air space directly above a location on the ground; the beginning of space and the ending of the air is considered as 100km above the ground according to the physical explanation that the air pressure is too low for a lifting body to generate meaningful lift force without exceeding orbital velocity. In most industrial countries, the aerospace industry is a cooperation of public and private industries. For example, several countries have a civilian space program funded by the government through tax collection, such as National Aeronautics and Space Administration in the United States, European Space Agency in Europe, the Canadian Space Agency in Canada, Indian Space Research Organisation in India, Japanese Aeronautics Exploration Agency in Japan, RKA in Russia, China National Space Administration in China, SUPARCO in Pakistan, Iranian Space Agency in Iran, Korea Aerospace Research Institute in South Korea.
Along with these public space programs, many companies produce technical tools and components such as spaceships and satellites. Some known companies involved in space programs include Boeing, Airbus, SpaceX, Lockheed Martin, United Technologies, MacDonald Dettwiler and Northrop Grumman; these companies are involved in other areas of aerospace such as the construction of aircraft. Modern aerospace began with Engineer George Cayley in 1799. Cayley proposed an aircraft with a "fixed wing and a horizontal and vertical tail," defining characteristics of the modern airplane; the 19th century saw the creation of the Aeronautical Society of Great Britain, the American Rocketry Society, the Institute of Aeronautical Sciences, all of which made aeronautics a more serious scientific discipline. Airmen like Otto Lilienthal, who introduced cambered airfoils in 1891, used gliders to analyze aerodynamic forces; the Wright brothers read several of his publications. They found inspiration in Octave Chanute, an airman and the author of Progress in Flying Machines.
It was the preliminary work of Cayley, Lilienthal and other early aerospace engineers that brought about the first powered sustained flight at Kitty Hawk, North Carolina on December 17, 1903, by the Wright brothers. War and science fiction inspired great minds like Konstantin Tsiolkovsky and Wernher von Braun to achieve flight beyond the atmosphere; the launch of Sputnik 1 in October 1957 started the Space Age, on July 20, 1969 Apollo 11 achieved the first manned moon landing. In April 1981, the Space Shuttle Columbia launched, the start of regular manned access to orbital space. A sustained human presence in orbital space started with "Mir" in 1986 and is continued by the "International Space Station". Space commercialization and space tourism are more recent features of aerospace. Aerospace manufacturing is a high-technology industry that produces "aircraft, guided missiles, space vehicles, aircraft engines, propulsion units, related parts". Most of the industry is geared toward governmental work.
For each original equipment manufacturer, the US government has assigned a Commercial and Government Entity code. These codes help to identify each manufacturer, repair facilities, other critical aftermarket vendors in the aerospace industry. In the United States, the Department of Defense and the National Aeronautics and Space Administration are the two largest consumers of aerospace technology and products. Others include the large airline industry; the aerospace industry employed 472,000 wage and salary workers in 2006. Most of those jobs were in Washington state and in California, with Missouri, New York and Texas being important; the leading aerospace manufacturers in the U. S. are United Technologies Corporation, SpaceX, Northrop Grumman and Lockheed Martin. These manufacturers are facing an increasing labor shortage as skilled U. S. workers retire. Apprenticeship programs such as the Aerospace Joint Apprenticeship Council work in collaboration with Washington state aerospace employers and community colleges to train new manufacturing employees to keep the industry supplied.
Important locations of the civilian aerospace industry worldwide include Washington state, California. In the European Union, aerospace companies such as EADS, BAE Systems, Dassault, Saab AB and Leonardo S.p. A. account for a large share of the global aerospace industry and research effort, with the European Space Agency as one of the largest consumers of aerospace technology and products. In India, Bangalore is a major center of the aerospace industry, where Hindustan Aeronautics Limited, the National Aerospace Laboratories and the Indian Space Research Organisation are headquartered; the Indian Space Research Organisation launched India's first Moon orbiter, Chandrayaan-1, in October 2008. In Russia, large aerospace companies like Oboronprom and the United Aircraft Building Corporation are among the major global players