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Essay / What is interstellar travel and is it really possible?
Interstellar travel is the idea of traveling from one star system or planetary system to another by means of spacecraft with or unmanned. Such a feat would be exceptionally difficult. For example, interplanetary travel within our own solar system is generally less than 30 AU or distances between Earth and the Sun. Distances for interstellar travel would be at least hundreds of thousands of times greater than any attempted mission today. Thus, this type of displacement constitutes its own unit of measurement called light years. The unit is expressed as a fraction of the speed of light, because it is believed that such travel would require that speed or would be subject to excruciatingly long travel times of decades or even millennia. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay The excessive speeds required to complete interstellar travel in a human lifetime exceed the current propulsion capabilities of spacecraft. Even in theoretical contexts, the amount of energy required to reach near-light speeds is lavish compared to the most generous modern energy production techniques. To put this into perspective, the Voyager 1 space probe only traveled 1/600 of a light year in 30 years at a speed of 1/18,000 the speed of light. The closest star to the exoplanets is known as Proxima Centauri. At Voyager's speed, it would take the probe approximately 80,000 years in total to reach the system from Earth (Dunbar). The kinetic energy required to reduce these travel times to a few decades for possible human travel is astronomical. It would take millions of times more energy than is currently possible to complete one trip in a lifetime. This is because the speed required is thousands of times greater than the capabilities of any modern spacecraft. To better visualize this, the formula for kinetic energy is K=½mv^2 where K is the kinetic energy, m is the final mass, and v is the speed. To reach even a tenth of the speed of light would require 125 terawatt hours. This is equivalent to the world's annual energy consumption. This is a huge obstacle to overcome if we ever want to travel interstellar. The onboard energy system would have to be unimaginably efficient and the fuel itself light enough not to hamper the viability of the kinetic energy formula. Another issue regarding interstellar travel concerns the effects of interstellar dust and gas on a spacecraft. Traveling at near-light speeds would increase the knitting energy of these particles and increase the damage inflicted and therefore must be considered when designing an interstellar vehicle. Micrometeoroids and other small space debris could be particularly dangerous because they directly impact the crew. Additionally, the unknown of larger space objects poses a more dangerous threat to any proposed mission. Fortunately, some proposals have been made to mitigate these risks. Another issue concerns the psychological effects of isolation on any crew involved in an interstellar mission. Add to this exposure to ionizing radiation and the breakdown of the body in weightless environments, and many medical problems need to be addressed. The final problem to resolve when trying to validate interstellar travel is choosing the right time to launch a mission. Technologyis improving at such a rapid rate that many argue we should not pursue such travel at all if it cannot be achieved within 50 years. This logic is based on the idea that if we could find a method of interstellar travel, the ship would likely travel at a relatively slow speed compared to something developed years later. Thus, a later launched mission could surpass the previously launched mission in transit if technology continues to improve at an exponential rate. One scientist who thought long and hard about this concept is Andrew Kennedy. He states that if a journey has been calculated with the expectation of growth, a minimum travel speed can be derived at which spaceships departing after will not replace those departing before. Despite the challenges mentioned above, there are 59 known star systems within it. 40 light years from our Sun. Of these 59 systems, the ten closest have been identified as possible targets for interstellar travel. The first is the closest system, Alpha Centauri. It is about 4.3 light years away and contains three stars. One of these stars is very similar to the Sun and in August 2016, an Earth-like exoplanet was discovered orbiting in the habitable zone. The second closest system is Barnard's Star which is 6 light years from the Sun. It is a small red dwarf, but the second closest solar system to ours. Sirius is located 8.7 light years from the Sun and is composed of two stars, including a white dwarf. Next is the Esilion Eridani at 10.8 light years. The system contains a single star smaller and cooler than the Sun, but also includes two asteroid belts. It is likely that this system has a solar system type planetary system. The Tau Ceti system has a single Sun-like star and is also likely to contain a solar system-like planetary system. At 11.8 light years, it promises the presence of five planets in two potentially habitable zones. The next system is Wolf 1061 and is about 14 light years away. There is a planet there more than 4 times the size of Earth which would have rocky terrain. In addition, it is located in an area in which the possibility of the presence of water is probable. At 20.3 light years away, the Gliese 581 planetary system is a multiplanetary system with a confirmed potentially habitable exoplanet. Gliese 667C is about 22 light years away and is believed to have a system of six planets, at least three of which are in an area in which water is likely. Twenty-five light years away, Vega is a relatively new system believed to be in the process of planetary formation. Finally, TRAPPIST-1 is a system located 39 light years away in which seven Earth-like planets exist. Interstellar travel will be necessary to verify the presence of life or the possibility of colonization on any of these planets within the above systems. Therefore, methods to achieve this have been proposed. First, in line with modern propulsion technologies, the idea of relatively slow unmanned missions has been developed. These concepts include Breakthrough Starshot and Project Dragonfly, Longshot, Icarus and Daedalus. These probes would be similar to the Voyager program and would take an incredibly long time to reach their targets. Additionally, there are concerns about the limits to the longevity of in-vehicle technology. Another method addresses the problem of necessary speed by significantly reducing the mass of the space vehicle. These “nanoprobes” are being developed at the University of Michigan and require a nanoparticle-based propellant to work. Their light weightmeans they would require much less energy to accelerate and plans for on-board solar cells would be used to persistently accelerate them. Although conceptually possible, there is still much work to be done before this concept comes to fruition. Additionally, the small size will pose other obstacles to overcome. The probes would be subjected to magnetic fields and would deviate from their trajectory, for example. There are some proposals for manned missions assuming that travel at near light speed is not feasible. The first concept is known as the generation ship or world ship. It is an interstellar ark in the sense that those who arrive at the destination would be the descendants of those who started the mission. While this would solve the time problem, it presents many other challenges. First, building such a large ship is currently not possible. Additionally, the amount of energy required to launch it would be astronomically expensive. Furthermore, even if the journey begins smoothly, biological and sociological problems will inevitably arise as the spacecraft ventures toward its destination. Theoretical solutions to these aforementioned problems include science fiction ideas about suspended animation or cryonic preservation. Neither of these solutions is currently possible, but by leaving passengers inert for most of the journey, the psychological and sociological problems associated with confinement on a ship could be avoided. Additionally, fewer resources would be required for the trip assuming the passengers' state resembles hibernation. Another idea is a combination of robotic travel and human cargo. Theoretically, space colonization could take place if embryos were frozen as cargo and brought to their destination by automated spaceflight. A host of other problems would arise with this method, such as the absence of parents to raise the children and the development of artificial wombs. Assuming significant improvements in spacecraft acceleration in the future, some benefits of near-light speed travel will emerge. One of them is time dilation. This essentially reduces the time spent by a traveler as they increase their speed. For example, a clock on an interstellar ship would run slower than an identical clock on Earth if the ship accelerated at a constant rate. This phenomenon would allow a round trip to almost anywhere in the galaxy in 40 years of ship time at a constant acceleration of 1 g. However, upon his return, the time spent on Earth would have been significantly longer. For example, traveling to the Milky Way, located 30,000 light years from Earth, and returning in 40 years by boat, would represent more than 60,000 Earth years. Despite these perceived disadvantages, the event allows travel beyond the originally planned maximum of 20 light years and benefits the possibilities of interstellar travel. Achieving time dilation requires constant acceleration, which presents enormous challenges but would represent the fastest travel times. Sufficient fuel should be kept on board to allow constant acceleration during the first half of the trip and enough fuel for constant deceleration during the second half. This is due to Newton's laws of motion, as the spacecraft would have to stop at its destination. Not only would this make the trip relatively quick, but it would also give a sense of gravity to those on board. However, such a quantity of fuel would be exorbitant. Another problem with hyperbolic motion..