Interstellar travel is a term used for hypothetical or hypothetical flying between stars or planetary systems. Interstellar travel will be much more difficult than interplanetary spaceflight; the distance between the planets in the Solar System is less than 30 units of astronomy (AU) - whereas the interstellar distance is usually hundreds of thousands of AU, and is usually expressed in light years. Because of the width of the distance, interstellar travel will require a high percentage of the speed of light; enormous travel time, which lasts from several decades to the millennium or longer; or a combination of both.
The speed required for interstellar travel in a human lifetime far outweighs what a current spacecraft can provide. Even with a highly efficient hypothetical propulsion system, the kinetic energy corresponding to that speed is enormous according to current energy production standards. Moreover, collisions by spacecraft with dust and cosmic gas can produce very harmful effects for both passengers and the spacecraft itself.
A number of strategies have been proposed to address these issues, ranging from the giant arks that will bring the entire community and ecosystem, to the microscopic spacecraft. Many different spacecraft propulsion systems have been proposed to provide the required spacecraft velocities, including nuclear propulsion, lighted propulsion, and methods based on speculative physics.
For interstellar travel both under siege and uncontrolled, considerable technological and economic challenges need to be met. Even the most optimistic view of interstellar travels sees it only as a decent decade from now - a more general view is that it is a century or so. However, apart from the challenge, if the interstellar journey should be realized, then the various scientific benefits can be expected.
Most interstellar travel concepts require a developed space logistics system capable of moving millions of tonnes to a construction site, and most will require gigawatt-scale power for construction or power (such as the Star Wisp or Light Sail concept). Such systems can grow organically if space-based solar power becomes an important component of the Earth's energy mix. Consumer demand for multi-terawatt systems will automatically create the multi-million ton/year logistics system required.
Video Interstellar travel
Challenges
Interstellar spacing
The distance between the planets in the Solar System is often measured in astronomical units (AU), defined as the mean distance between the Sun and the Earth, about 1.5 ÃÆ' - 10 8 kilometers (93 million miles). Venus, another planet closest to Earth is (in the closest approach) 0.28 AU. Neptune, the furthest planet from the Sun, is 29.8 SA. In January 2018, VoyagerÃ, 1, the farthest man-made object from Earth, is 141.5 AU.
The closest known star, Proxima Centauri, is about 268,332 AU, or more than 9,000 times farther than Neptune.
Therefore, the distance between stars is usually expressed in light years, which is defined as the distance traveled by the rays of light in a year. Light in a vacuum moves about 300,000 kilometers (186,000 mi) per second, so this is about 9,461 ÃÆ' - 10 12 kilometers (5,879Ã, trillion miles) or 1 lamp- year (63,241 AU) in a year. Proxima Centauri is 4,243 light-years away.
Another way to understand the width of interstellar distance is by scaling: One of the closest stars to the Sun, Alpha Centauri A (a star like the Sun), can be described by scaling the Earth-Sun distance to one meter (3.28 ft). At this scale, the distance to Alpha Centauri A will be 276 kilometers (171 miles).
The fastest spacecraft ever shipped, Voyager 1, has covered 1/600 light years in 30 years and is currently moving at 1/18,000 the speed of light. At this rate, a trip to Proxima Centauri will take 80,000 years.
Energy needed
A significant factor contributing to adversity is the energy that must be provided to get reasonable travel time. The lower limit for required energy is kinetic energy
The speed for several manned manned journeys to even the closest star is several thousand times larger than the current space vehicle. This means that because term in the kinetic energy formula, millions of times more energy is required. Accelerating a ton to one tenth of the speed of light requires at least 450 petajoules or 4.50 sponges (joule or 125 terawatt-hours (world energy consumption 2008 is 143,851 Ã, terawatt -hours), without factoring the efficiency of the propulsion mechanism. This energy must be generated onboard from stored fuel, harvested from interstellar medium, or projected at great distances.
Interstellar medium
Knowledge of the nature of the interstellar gas and the dust through which the vehicle passes is crucial for the design of interstellar space missions. The main problem in traveling at very high speeds is that interstellar dust can cause great damage to aircraft, due to the high relative speed and large kinetic energy involved. A variety of shielding methods to address this problem have been proposed. Larger objects (such as macroscopic dust grains) are much more common, but will be much more damaging. The risk of the effects of these objects, and these risk mitigation methods, have been discussed in the literature, but many are unknown and, because the distribution of non-homogeneous interstellar matter around the Sun, will depend on the direction taken. Although high-density interstellar mediums can cause difficulties for many concepts of interstellar travel, interstellar ramjets, and some concepts proposed to slow down interstellar interstellar spacecraft, would actually benefit from a more dense interstellar medium.
Dangers
The interstellar crew will face several significant dangers, including the psychological effects of long-term isolation, the effects of ionizing radiation exposure, and the physiological effects of weight on muscles, joints, bones, immune system, and eyes. There is also the risk of impact by micrometeoroids and other space debris. These risks are challenges that can not be overcome.
Wait for calculation
It has been argued that interstellar missions that can not be completed within 50 years should not start at all. On the contrary, assuming that civilization is still on the speed curve of the propulsion system and has not reached the limit, resources must be invested in designing a better propulsion system. This is because a slow spacecraft may be bypassed by another mission that is sent later with a more advanced impulse (endless postulates unrelenting). On the other hand, Andrew Kennedy has shown that if one calculates the travel time to a given destination as the rate of travel traveling from growth (even exponential growth) increases, there is a clear minimum in total time to that goal from now on. The cruises made before the minimum will be taken over by those who leave the minimum, while those who leave after the minimum will never surpass those who leave at the minimum.
Maps Interstellar travel
Primary target for interstellar travel
There are 59 known star systems in 40 light-years of the Sun, containing 81 visible stars. The following can be considered a major target for interstellar missions:
The existing and short-term astronomical technologies are able to find planetary systems around these objects, increasing their potential for exploration
Proposed method
Probe is slow, not tracked
The slow interstellar mission based on current and near future propulsion technology is associated with travel times ranging from about a hundred years to thousands of years. The mission consists of sending a robot probe to the nearest star for exploration, similar to an interplanetary probe as used in the Voyager program. By bringing with the crew, mission costs and complexities are significantly reduced even though technology age is still an important issue in addition to getting reasonable travel speeds. Proposed concepts include Project Daedalus, Project Icarus, Project Dragonfly, Project Longshot, and later, Breakthrough Starshot.
Fast, unracked probes
Nanoprobes
Near-Lightspeed nano spacecraft may be possible in the near future built on existing microchip technology with newly developed nano thruster. Researchers at the University of Michigan are developing a propulsion that uses nanoparticles as propellants. Their technology is called "thruster nanoparticle field extraction", or nanoFET. This device acts like a small particle accelerator that fires conductive nanoparticles into space.
Michio Kaku, a theoretical physicist, has suggested that clouds of "smart dust" are sent to stars, which may become possible with advances in nanotechnology. Kaku also notes that a large number of nanoprobes will need to be shipped because of very small probe vulnerabilities to be easily deflected by magnetic fields, micrometeorites and other hazards to ensure the possibility that at least one nanoprobe will survive the journey and reach its destination.
Given the light weight of this probe, it takes less energy to speed it up. With solar cells onboard, they can continue to accelerate using solar power. One can imagine a day when a fleet of millions or even billions of these particles clustered to distant stars almost at the speed of light and forwards the signal back to Earth through a wide network of interstellar communications.
As a short-term solution, the laser-driven small interstellar probe, based on CubeSat technology is currently proposed in the context of Project Dragonfly.
A slow and manned mission
In crew missions, the duration of slow interstellar travel presents major obstacles and existing concepts deal with these issues in different ways. They can be distinguished by the "state" in which humans are transported on-board from the spacecraft.
Ship generation
A generation ship (or world ship ) is a type of inter-star ship where the crew arriving at the destination are descended from those who embark on a journey. The current generation ships are unfeasible because of the difficulty of building a ship on a much needed scale and the great biological and sociological problems that life on board such a ship increases.
Pending animation
Scientists and writers have postulated various techniques for suspended animation. These include human hibernation and cryonic preservation. Although currently impractical, they offer the possibility of a sleeping vessel in which passengers lie inert for long travel durations.
Frozen embryo
An interstellar robotic mission that carries a number of frozen early-stage human embryos is another theoretical possibility. This method of space colonization requires, inter alia, the development of an artificial uterus, previous detection of habitable terrestrial planets, and progress in the field of moving robots and educational robots that will replace human parents.
Island jumps through interstellar space
The interstellar space is not entirely empty; it contains trillions of icy objects ranging from a small asteroid (Oort cloud) to a possible evil planet. There may be a way to utilize this resource for most interstellar travel, slowly jumping from one body to another or preparing your way along the way.
Rapid mission
If the spacecraft could average 10 percent of the speed of light (and slow down at destination, for manned missions), this would be enough to reach Proxima Centauri in forty years. Several propulsion concepts have been proposed that may eventually be developed to achieve this (see also section below on propulsion methods), but none are ready for short-term (decades) development at an acceptable cost.
Widening time
Assuming a faster trip than light is impossible, one might conclude that humans can never travel much farther from Earth than 20 light years if the traveler is active between the ages of 20 and 60 years. A traveler can never reach more than a few star systems that exist within the light 20-year limit of Earth. This, however, fails to account for the widening of relativistic time. The clock on an interstellar ship will run much slower than Earth clocks, so if the ship's engine is able to continue to produce about 1 g of acceleration (which is convenient for humans), the ship can reach almost anywhere in the galaxy and return to Earth in 40 years of ship time see diagram). Upon returning, there will be a difference between the time elapsed on the astronaut's ship and the time elapsed on Earth.
For example, a spacecraft may travel to a 32-light-year star, initially accelerating at a constant 1.03g (ie 10.1 m/s 2 ) for 1.32 years (ship time), then stopping it engine and glide for the next 17.3 years (ship time) at a constant speed, then slows down again for 1.32 years of ship, and stops at the destination. After a short visit, astronauts can return to Earth in the same way. After a full round trip, the clock on board showed that 40 years had passed, but according to those on Earth, the ship was back 76 years after its launch.
From an astronaut point of view, the onboard clock seems to be running normally. The front star seems to be approaching at a velocity of 0.87 light years per year of the vessel. The universe will seem to contract along the direction of the journey to half the size it has when the ship is resting; the distance between the star and the Sun appears to be 16 light years as measured by astronauts.
At higher speeds, the time on the boat will run more slowly, allowing astronauts to travel to the Milky Way center (30,000 light-years from Earth) and back within 40 years of the ship. But the speed according to Earth clock will always be less than 1 light year per Earth year, so, when returning home, astronauts will discover that more than 60 thousand years will pass on Earth.
Constant acceleration
Regardless of how it is achieved, a propulsion system that can produce continuous acceleration from start to finish will be the fastest travel method. The constant acceleration journey is one where the propulsion system accelerates the vessel at a constant rate for the first half of the journey, and then decreases its speed for the second half, so that it arrives at a stationary relative destination to where it began. If this is done with an acceleration similar to that experienced on the surface of the Earth, it would have the added advantage of producing an artificial "gravity" for the crew. Supplying the required energy, however, will be very expensive with today's technology.
From the perspective of planetary observers, the ship will appear to accelerate steadily at first, but then more gradually as it approaches the speed of light (which can not exceed). It will experience hyperbolic movements. The ship will be near the speed of light after about a year accelerates and stays at that speed until it brakes for the end of the journey.
From the perspective of the onboard observer, the crew will feel the gravitational field opposite to the acceleration of the engine, and the universe ahead will appear to fall in that field, undergoing hyperbolic movements. As part of this, the distance between objects toward the movement of the ship will gradually contract until the ship begins to decrease its speed, by which time the onboard observer's experience of the gravitational field will be reversed.
When the ship reaches its destination, if it wants to exchange messages with its home planet, it will find that less time has elapsed on the ship than it has passed for planetary observers, due to the widening of time and the long contraction.
The result is a very fast journey for the crew.
Propulsion
Rocket concept
All rocket concepts are limited by rocket equations, which regulate the speed of available characteristics as a function of the exhaust velocity and mass ratio, the initial ratio ( M 0 , including fuel) to the end (< i> M 1 , spent fuel) mass.
Extremely high specific forces, the ratio of thrust to total vehicle mass, are required to achieve interstellar targets within a sub-century timeframe. Some heat transfer is unavoidable and extreme heating loads should be adequately addressed.
Thus, for the concept of interstellar rockets of all technologies, major engineering problems (rarely explicitly discussed) limit the heat transfer from the discharge stream back to the vehicle.
Ion Machine
The type of electric drive, a spacecraft like Dawn uses an ion machine. In an ion machine, electric power is used to make propellant-charged particles, usually xenon gas, and accelerate to very high speeds. The conventional rocket exhaust speed is limited by the chemical energy stored in the molecular bond of the fuel, which limits the thrust to about 5 km/sec. This gives them high power (for takeoff from Earth, for example) but limits top speed. In contrast, ion engines have low power, but the top speed is principally limited only by the power available on spacecraft and on accelerated gas ions. The exhaust velocity of charged particles ranges from 15 km/second to 35 km/sec.
Powerful nuclear division
Fission-electric
The nuclear-electric or plasma engine, which operates for a long time with low thrust and is powered by a fission reactor, has the potential to reach much greater speeds than chemical-fueled vehicles or nuclear thermal rockets. Such vehicles may have the potential to drive exploration of the Solar System with a reasonable travel time of the century. Due to their low thrust drive, they will be limited to off-planet, space operations. The electric-powered spacecraft powered by portable power sources, say nuclear reactors, which produce only small accelerations, will take centuries to reach for example 15% of the speed of light, making it unsuitable for interstellar flight during a single human life.
Fission-fragment
Rocket fractions use nuclear fission to create high-speed jets of fission fragments, released at speeds of up to 12,000 km/s (7,500 mi/sec). By fission, the energy output is about 0.1% of the total energy-mass of the reactor fuel and limits the effective discharge rate to about 5% of the speed of light. For maximum speed, the reaction mass must be optimally composed of fission products, "ash" from the primary energy source, so that no extra reaction mass is to be recorded in the mass ratio.
Nuclear nuclear
Based on work in the late 1950s and early 1960s, it was technically possible to build a spacecraft with a nuclear pulse drive engine, driven by a series of nuclear explosions. This propulsion system contains very high specific impulse prospects (space travel equivalent of a fuel economy) and high specific power.
Project Orion team member Freeman Dyson proposed in 1968 an interstellar spacecraft using nuclear pulse propulsion using pure deuterium fusion blasting with a very high fuel-burn fraction. He calculates a 15,000 km/s exhaust velocity and a 100,000-ton space vehicle capable of reaching 20,000 km/s delta-v allowing time to fly to Alpha Centauri from 130 years. Subsequent research shows that the upper cruising speed theoretically can be achieved by Orion Tard-Ulam-powered oron units is star-powered, assuming no fuel is stored to slow down currents, about 8% to 10% of the speed of light (0.08- 0.1 c). Orion atom (fission) can reach maybe 3% -5% of the speed of light. A nuclear power vessel pushing the spacecraft backed by a catalyzed nuclear-antimatter drive unit will be the same in the range of 10% and the pure-antimatter destruction rocket rocket will theoretically be capable of gaining speeds of 50% to 80% of the speed of light. In each case the fuel savings to slow down half the maximum speed. The concept of using a magnetic screen to slow down the spacecraft when approaching its destination has been discussed as an alternative to using propellant, this will allow the ship to travel near the maximum theoretical speed. Alternative designs that use similar principles include Project Longshot, Project Daedalus, and Mini-Mag Orion. The principle of external nuclear pulse propulsion to maximize sustainable power remains a common feature among serious concepts for interstellar flight without radiant external forces and for very high interplanetary flights.
In the 1970s the concept of Nuclear Pulse Propulsion was further refined by the Daedalus Project by using an inertial fusion of external inertial fusion, in this case resulting in a fusion explosion through the compression of fusion fuel pellets with high-powered electron beams. Since then, lasers, ion beams, neutral particle beams and hyper-kinetic projectiles have been suggested to produce nuclear pulses for propulsion purposes.
The current obstacle to the development of any nuclear-explosion-powered spacecraft is the 1963 Partial Test Ban Treaty, which includes a ban on the detonation of nuclear devices (even non-weapon-based) in outer space. This agreement will, therefore, need to be renegotiated, although projects on the scale of interstellar missions using current technology will likely require international cooperation at least on the International Space Station scale.
Nuclear fusion rockets
Fusion rocket starships, backed by nuclear fusion reactions, should be able to reach a 10% order of light, based on energy considerations only. In theory, a large number of stages can propel vehicles arbitrarily close to the speed of light. It will "burn" light fuels such as deuterium, tritium, 3 Dia, 11 B, and 7 Li. Since the fusion results in about 0.3-0.9% of the nuclear fuel mass as the energy released, its energy is more advantageous than fission, which releases the & lt; 0.1% of the fuel mass energy. Maximum exhaust velocity that is potentially available energetically is higher than fission, usually 4-10% of c. However, the most easily accessible fusion reactions release most of their energy as high energy neutrons, which are a significant source of energy loss. Thus, although these concepts seem to offer the best (nearest term) prospects for travel to nearby stars in a lifetime (long), they still involve major technological and technological difficulties, which may turn violent for decades or century.
Initial studies included the Daedalus Project, conducted by the British Interplanetary Society in 1973-1978, and Project Longshot, a student project sponsored by NASA and the US Naval Academy, completed in 1988. Another fairly detailed vehicle system, "Discovery II" designed and optimized for exploration of the Solar System, based on the reaction of D 3 He, but using hydrogen as a reaction mass, has been described by a team from the NASA Glenn Research Center. This reaches characteristic speed & gt; 300 km/s with acceleration ~ 1,7o10 -3 g, with the initial mass of the ~ 1700 metric ton vessel, and the payload fraction above 10%. While this is still far from the requirements for interstellar travel on a human time scale, this study seems to represent a reasonable benchmark against what might be approached in decades, which is unlikely beyond the present circumstances. Based on the concept of 2.2% fuel break it can reach the exhaust speed of pure fusion product ~ 3,000 km/s. An antimatter rocket
An antimatter rocket will have a much higher energy density and a special boost than any other proposed rocket class. If energy resources and efficient production methods are found to make antimatter in the required amount and store it safely, it is theoretically possible to reach a speed of several tens of percent of the light. Whether antimatter propulsion can lead to higher velocity (& gt; 90% of light) in which the relativistic time span will become more visible, thus making the time pass for a slower rate for travelers as perceived by outside observers, large amount of antimatter needed.
Speculating that antimatter production and storage should be feasible, two further issues need to be considered. First, in the destruction of antimatter, most of the energy is lost as high-energy gamma-ray radiation, and especially also as a neutrino, so only about 40% of mc 2 will be actually available if the antimatter was only allowed to destroy it into thermal radiation. Even so, the energy available for propulsion will be much higher than ~ 1% of the mc 2 the result of nuclear fusion, the next best competitor candidate.
Second, the heat transfer from the exhaust to the vehicle appears to be transferring enormous wasted energy into the vessel (eg for 0.1
Recently, Friedwardt Winterberg proposed that rocket gamma-ray laser photon GeV-gamma-antimatter material is made possible by proton-antiproton pinch relativistic discharges, where a recall of laser light is transmitted by the MÃÆ'¶ssbauer effect onto the spacecraft.
Rocket with external energy source
Rockets that gain their power from external sources, such as lasers, can replace their internal energy sources with energy collectors, potentially reducing mass of ships on a large scale and allowing much higher travel speeds. Geoffrey A. Landis has proposed for interstellar investigation, with energy supplied by an external laser from a base station that emits an Ion thruster.
Non-rocket concepts
The problem with all traditional rocket propulsion methods is that the spacecraft needs to carry its fuel with it, making it very large, in accordance with the rocket equation. Some concepts seek to escape from this problem:
ramjets Interstellar
In 1960, Robert W. Bussard proposed a Bussard ramjet, a fusion rocket in which a large spoon would collect hydrogen spreading in interstellar space, "burn" it rapidly using a proton-proton chain reaction, and throw it out of the back. Subsequent calculations with more accurate estimates indicate that the resulting thrust will be less than the obstacles caused by the design of the spoon. But this idea is interesting because the fuel will be collected on the way (commensurate with the concept of energy harvesting ), so the craft can theoretically accelerate near the speed of light. This limitation is due to the fact that the reaction can only accelerate propellant to 0.12c. Thus the drag captures interstellar dust and pushes the same dust up to 0.12c to be the same as the speed of 0.12c, preventing further acceleration.
Beamed propulsion
A light screen or magnetic screen powered by a laser accelerator or large particle in a home star system potentially reaches a greater speed than a rocket or pulse propulsion method, since it does not need to carry its own reaction mass and therefore only needs to accelerate the aircraft's charge. Robert L. Forward proposed a way to slow the sailing of interstellar light within the destination star system without the need for a laser array to be present in that system. In this scheme, a smaller secondary screen is deployed to the back of the spacecraft, while the large main screen is detached from the plane to continue moving forward on its own. Light is reflected from the large main screen to the secondary screen, which is used to reduce the speed of the secondary screen and the space shuttle's charge. In 2002, Geoffrey A. Landis of the NASA Glen Research Center also proposed a laser-powered sailboat, propulsion, which will host a diamond screen (with a thickness of a few nanometers) powered with the use of solar energy. With this proposal, this interstellar ship, theoretically, can reach 10 percent the speed of light.
A magnetic screen can also reduce its speed at the destination regardless of the carrying fuel or the driving beam of the destination system, by interacting with the plasma found in the solar wind from the star and the interstellar medium.
The following table lists some examples of concepts using radiant laser propulsion as proposed by physicist Robert L. Forward:
Interstellar travel catalog to use full photogravitational help
The following table is based on the work of Heller, Hippke, and Kervella.
- Help in a row? Cen A and B can allow travel time of up to 75 years for both stars.
- Lightsail has a nominal mass-to-surface ratio (? nom ) of 8.6ÃÆ' â € "10 -4 gram m -2 for a nominal class graphene display.
- Lightsail Area, about 10 5 m 2 = (316 m) 2
- Speed ​​up to 37,300 km km -1 (12.5% ​​c)
Pre-accelerated fuel
Achieving start-stop interstellar travel time less than the lifetime of a human requires a mass ratio of between 1,000 and 1,000,000, even for closer stars. This can be achieved by multi-staged vehicles on a large scale. Other large linear accelerators can encourage fuel to spew driven vehicle spaces, avoiding the limitations of Rocket equations.
Theoretical concepts
Travel faster than light
Scientists and authors have postulated a number of possible ways to transcend the speed of light, but even the most serious-minded of these are highly speculative.
It is also debatable whether the faster travel of light is physically possible, partly because of causality concerns: travel faster than light can, under some circumstances, allow travel backward in time in the context of special relativity. The proposed mechanism for faster travel of light in the general theory of relativity requires the existence of exotic matter and it is not known whether this can be produced in sufficient quantities.
Alcubierre drive
In physics, the Alcubierre drive is based on arguments, within the framework of general relativity and without the introduction of the wormhole, that it is possible to modify spacetime in a way that allows spacecraft to travel at great speed arbitrarily by local spacetime expansions behind the spacecraft and contraction in front of him. Nevertheless, this concept would require a spacecraft to combine an exotic material region, or a negative mass hypothetical concept.
Artificial black hole
The theoretical idea for enabling interstellar travel is to push the space ship by creating an artificial black hole and using a parabolic reflector to reflect Hawking radiation. Though beyond current technological capabilities, the black hole spacecraft offers several advantages over other possible methods. Getting a black hole to act as a power source and machine also requires a way to turn Hawking radiation into energy and drive. One potential method involves placing a hole in the focal point of the parabolic reflector attached to the ship, creating a forward impulse. A slightly easier, but less efficient method would involve simply absorbing all the gamma radiation that goes to the front of the ship to push it forward, and allowing the rest to shoot backwards.
Wormholes
The wormhole is the cursed distortion in spacetime formulated by the theorists to connect two random points in the universe, across the Einstein-Rosen Bridge. It is unknown whether the wormhole might be in practice. Although there is a solution to Einstein's equations of general relativity that allow for wormholes, all known solutions today involve several assumptions, such as the presence of negative masses, which may not be physical. However, Cramer et al. contends that such wormholes may have been created in the early universe, stabilized by cosmic strings. The general theory of wormhole is discussed by Visser in the book Lorentzian Wormholes .
Hyperdrive
If Felber's allegation is correct, ie a mass moving at 57.7% C produces an anti-gravity ray then Orion drives may be able to act as a prelude, and undiscovered technologies based on anti-matter rejection have theorized effects under exotic conditions such as entanglement that directly manipulating space-time to open windows to hyperspace. It could exploit physics in the extradimensional space to travel very quickly through galaxies. The side effect here is because the need for a second vehicle to slow it down would be a one-way trip, though other concepts like the sun screen can be used to slow down near the destination. All components can be reused and also provide a very effective SETI target if other species use this technology. It is also possible that hyperdrive leaps can be limited to discrete areas such as near stars due to gravity wells.
Design and study
Enzmann starship
The Enzmann starship, as detailed by G. Harry Stine in the October 1973 edition of Analog , is a design for future space ships, based on Robert Duncan-Enzmann's ideas. The spacecraft itself as proposed uses 12,000,000 tons of frozen deuterium balls to power 12-24 units of thermonuclear pulse propulsion. Twice during the Empire State Building and assembled in orbit, the spacecraft is part of a larger project that is preceded by an interstellar probe and telescopic observation of the target star system.
Project Hyperion
The Hyperion project, one of the Interstellar Icarus projects.
NASA Research
NASA has been researching interstellar travel since its formation, translated important foreign language papers and conducted preliminary studies on the application of fusion propulsion, in 1960, and laser propulsion, in 1970, to interstellar travel.
NASA's Breakthrough Propulsion Physics Program (ended in FY 2003 after 6 years, $ 1.2 million study, because "No near-sight breakthrough.") Identifying some of the breakthroughs needed for interstellar travel is possible.
Geoffrey A. Landis of the NASA Glenn Research Center stated that laser-powered interstellar sailboats may be launched within 50 years, using a new method of space travel. "I think that in the end we will do it, it's just a matter of when and who," Landis said in an interview. The rockets are too slow to send humans to interstellar missions. Instead, he envisioned the interstellar craft with a large screen, driven by a laser beam to about one-tenth the speed of light. It takes about 43 years to reach Alpha Centauri if it passes through the system. Stopping to stop at Alpha Centauri can increase the journey to 100 years, while travel without slowing raises the problem of making observations and measurements quite accurate and useful during fly-bys.
100 Stars Starship study
The 100 Year Starship (100YSS) is the name of the overall effort that will, during the next century, work to achieve interstellar travel. This effort will also be done by 100YSS moniker. The 100 Stars Starship study is the name of a one-year project to assess attributes and lay the groundwork for an organization that can pass on the 100 Stars Starship vision.
Harold ("Sonny") White of the NASA Space Center is a member of Icarus Interstellar, a nonprofit foundation whose mission is to realize interstellar flight before 2100. At the 100YSS meeting of 2012, he reported using lasers to try curving spacetime by 1 part in 10 million with the goal of helping to make the interstellar journey possible.
Other designs
- Project Orion, a manned cruise ship (1958-1968).
- The Daedalus project, an unmanned interstellar investigation (1973-1978).
- Starwisp, unmanned interstellar probe (1985).
- Project Longshot, unmanned interstellar investigation (1987-1988).
- Starseed/launcher, unmanned interstellar probe fleet (1996)
- The Valkyrie project, an unmanned crew (2009)
- Icarus Project, unmanned interstellar investigation (2009-2014).
- Sun diving, unmanned interstellar investigation
- The breakthrough of Starshot, an unmanned interstellar probe fleet, announced on April 12, 2016.
Non-profit organization
Several organizations dedicated to the research of interstellar propulsion and advocacy for this case exist throughout the world. It's still in its early stages, but it's supported by membership of various scientists, students, and professionals.
- 100 Years of Starshiphip
- Icarus Interstellar
- Tau Zero Foundation (USA)
- Initiatives for Interstellar Studies (UK)
- Fourth Millennium Foundation (Belgium)
- Cooperative Room Development (Canada)
Feasibility
Energy needs make interstellar travel very difficult. It has been reported that at the 2008 Joint Propulsion Conference, many scholars argue that it is unlikely that humans will explore beyond the Solar System. Brice N. Cassenti, a professor in the Department of Engineering and Science at Rensselaer Polytechnic Institute, states that at least 100 times the total worldwide energy output [in a given year] will be required to send the probe to the nearest star.
Astrophysicist Sten Odenwald stated that the basic problem is that through intensive research of thousands of detected exoplanets, most of the nearest destinations in 50 light years do not produce Earth-like planets in the star habitable zone. Given the multi-trillion dollar cost of some of the proposed technologies, travelers must spend up to 200 years traveling at a speed of 20% the speed of light to achieve the best known destinations. In addition, once travelers arrive at their destination (in any way), they will not be able to travel to the surface of the target world and set up colonies unless the atmosphere is not deadly. The prospect of such a journey, just to spend the rest of the colony's life in a closed habitat and roam outside in outer space, can remove many potential targets from the list.
Moving at speeds near the speed of light and facing small stationary objects such as sand grains would have fatal consequences. For example, one gram of material moving at 90% of the speed of light contains kinetic energy associated with a small nuclear bomb (about 30kt TNT).
Interstellar mission is not for human benefit
The exploration of high-speed missions to Alpha Centauri, as planned by the Breakthrough Starshot initiative, is projected to be realized in the 21st century. The alternative is probably to plan an unmanned slow cruise mission that takes thousands of years to arrive. This probe would not be beneficial to humans in the sense that one can not predict whether anyone in the world is interested in transmitted science data. An example is the Genesis mission, which aims to bring one-cell life, in the spirit of panspermia directed, to a habitable but otherwise barren planet. Explorer The crawl event is slowly complete, with a typical speed , related to about , can be slowed using magnetic screen. Unmanned missions that are not beneficial to humans, it will be worth it
Discovery of Planets Like Earth
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