Mankind has always dreamed of exploring the heavens and in the last millennium he has only scratched the surface of space exploration. The problem lies not in the lack of motivation or the lack of enthusiasm, but rather in the greatness of the expansion of the universe. The universe is a vast expanse of interstellar miracles that are at such a distance from each other that conventional technology in space travel renders itself ineffective and inadequate for human exploration. The closest three star system to Earth, Alpha Centauri, is the brightest star and is 4.
3 light years away from the sun. The velocity required to reach this star system in 10 years is 100,000 km/s. One can put that into perspective when it is compared with today’s unmanned missions which travel at 10km/s. Exotic Propulsion Systems are the “far out” dreams and thoughts of the scientists and space enthusiasts which are still being studied, researched, and explored. They are said to make the traveling to other planets and stars easy and affordable for common people.
Contemporary space travel uses rocket engines as the primary method of propulsion; this technology dates back as far as 360 B. C. (Erichsen, 2006). It is imperative that new methods of propulsion must be implemented for humans to realize space travel to the distant stars in their lifetime. Exotic propulsions systems may be the key to discovering the stars at a human time scale. There have been numerous researches and studies by the scientists, fictional writers, fictional film-producers, space-enthusiasts, and many space related firms about the advent of the exotic propulsion system.
Since technology has advanced to a much greater level it can be said that our future generation would be travelling to the galaxy and solar system for their vacations. However, it is still a long way till the scientists design a perfect solution for the traveling to outer space in human time. In 1996, an “antigravity propulsion system” was proposed by Dr. Franklin Felber at the “Space Technology and Applications International Forum” in Albuquerque. He has given hopes to the explorers of the space by devising a solution to “Einstien’s gravitational force field equation.
” Through this solution it might be possible to achieve speeds of “light” for the space craft without suffering the loss or “crushing” of the “contents” of the space craft. If the solution proposed by Dr. Felber works successfully it could work better than the previous solution known as “apergy” proposed in 1880 by author Percy Greg. Dr. Felber has stated that an object moving exactly 57. 7% faster than the “speed of light” will automatically “repel” other objects which are scattered around in a “antigravity beam” by that object.
The beam s said to “intensify” as the speed of light is approached by the object. His paper states that the object will “fall weightlessly” as it accelerates according to the speed of light. This solution is said to change the way and “views” of travel to the universe that is still unknown to a common human being. The problem with gravity and the solutions to overcome it has been a favorite topic of many writers and scientists, even fictional writers are interested in the topic of anti-gravity (Christensen, 2006).
Since technology has been advancing at a much rapid rate the space craft use today is considered to be a “luxury ship” in comparison to the “Mercury capsules” that marked the beginning of space exploration. Today, people have earth have visited various planets and they continue to explore the depths of the universe that has been created for us. According to NASA Explorers (2003) the idea of rockets and the way engines of rockets work has remained the same throughout the history.
The space engine should be able to aid the craft and crew to go around the “solar system” at a much faster speed. A way highlighted by the NASA Explorers is the use of the “Variable Specific Impulse Magnetoplasma Rocket (VASIMR). ” It is believed that this system would increase the speed of travel of various planets while decreasing the amount of fuel as well as protect the astronauts from being exposed to “radiation. ” This system is said to be known as the “plasma based propulsion system” which uses electronic power to “ionize fuel into plasma.
” The use of electric power is said to “heat and accelerate” the plasma system whereas the “magnetic field” works as a direction force and is “ejected” from the craft’s engine, this in return boosts the speed of the craft. The system is such that the “thrust” also varies which can produce a varying level of speed and acceleration. The fuel being used for VASMIR also have benefits attached to them, these fuels are ““hydrogen, helium, and deuterium. ” The usage of hydrogen is said to allow the re-fueling at any station in the space, as almost ever point in the solar system contains hydrogen.
Again, as mentioned above, this system protects the crew from radiation as hydrogen is said to be the “best known radiation shield. Even though this system is far from being used in today’s world it is said to be a weapon for the future advancements and explorations in the space and solar system around us. In 2006, the “European Space Agency (ESA) and the Australian National University” tested a new proposed design for the ion engine of the space craft which is said to improve the performance of the “present thrusters and marks a major step forward in space propulsion capability.
” Ion engines, a type of electric propulsion, is said to operate by accelerating through “beam of positively charged particles” and they are said to use the electric and magnetic field. The ESA is said to be using the new system on its current mission and is overly satisfied with the results which are proving to be 10 times more “fuel efficient” than the systems previously used. This new engine is called the “Dual-Stage 4-Grid (DS4G) ion thruster. ” The traditional ion system are said to operate on three “perforated grids” which contain numerous tiny holes attached to the “chamber” which holds the particles that are charged.
The first of these three grids is said to operate on low voltage whereas the second one has lower levels of volts. The difference in the volts is what attracts the charged particles from the chamber and “accelerates” the particles out in the space. They are said to operate more efficiently on higher voltage differences. However, sometimes a problem occurs when the ions from the low and high voltage area collide with each other and “erode” the “thruster.
” The new system is said to rely on the proposal of David Fearn, which solves the collision problem by the usage of “four grids” and instead of “one stage” it utilizes a process completed in “two-stages. ” The first of them is when the traditional grids are both operated at higher voltage, however, different from each other. The decrease in the volts difference aids the “ions” to “safely” come out of the “chamber,” while protecting the erosion of the two grids. The new stage or the second stage is when the two other grids are placed at a distance “downstream” and function on low voltages.
This difference between two grids enables the ions to be released at an accelerated rate in the space, and the “exits” of both pairs are also protected from eroding (Tarko, 2006). Even though many new systems can be developed the American Nuclear Society is said to support the usage of “nuclear based systems” for space exploration. According to them, the usage of the system is said to provide “electricity, heat, and propulsion for missions” which cannot be achieved through the usage of “solar power, fuel cells, and conventional chemical means.
” A nuclear based system is said to include radioisotope thermoelectric generators (RTGs), fission-based nuclear reactor power systems, nuclear thermal propulsion (NTP), nuclear electric propulsion (NEP), and propulsion systems which are made by “nuclear fusion and on other advanced nuclear technologies. ” United States, has been producing and launching RTGs for over 30 years and these have aided the mission reach further the orbit of Pluto. However, it is said that these systems are not “large enough” to support human life and the robotic missions which are coming up in the future.
It is said that through “nuclear fission reactors” a long term power and energy supply can be used to aid the missions of humans as well as robots. This system can also enable the mission to expand their projects outside the boundaries of “solar systems. ” NTP is said to provide the fastest way to reach destinations in outer worlds (The American Nuclear Society, 2009). NASA is also said to look into and agree with the usage of the “fission based nuclear engine” to aid there future expeditions (Malik, 2004).
NASA has been working on various technologies for future and one of the best technologies it plans to use for future propulsion is “aerocapture. ” The new technology is very comparable to “aerobarking,” the traditional system used by NASA is many of its expeditions to the outer world. However, aerocapture is said to have the ability to enable the altering of “flight trajectory” by the usage of “planet’s atmosphere. ” Aerocapture is also said to save on the fuel consumption by using a “vehicle in orbit.
” This system uses the gravity and physics of the planet that it is present on to guide itself (Malik, 2004). Another technology proposed for propulsion by NASA is the “Next Generation Electric Propulsion” which is said to have improved performance due to the usage of “ion engines to fission propulsion drivers. ” Also, it is said to have a higher level of throughput, is considered to be lightweight, and as mentioned before has a much powerful ion engine. It is said to be able to go on future missions, namely “Europa Lander, a Saturn Ring Observer, a Neptune Orbiter, and a Venus Surface Sample Return probe.
” Solar Sails is another future propulsion technique proposed by NASA which is “strong” and is made up of “lightweight composite materials” in shape of a “large sail. ” This is said to require no fueling as it relies on the solar ebergy by the sun to have a “steady push. ” The only problem that arises with this technology is the way to control it once it is in the space (David, 2002). When talk about the future of rockets come up most people think about “anti-matter rockets. ” Most people confuse them for being fictional; however, they truly exist in our world.
It is considered to be the most “expensive substance” on the Earth and is produced in small amounts in specifically designed facilities. It was estimated in 1999 that only 1 gram of anti-matter costs around $62. 5 trillion. However, the surprising part is that this discovery is not new or modern instead it goes back to 1920s when a German scientist proposed the substance to be used in propulsion. The reasoning behind this proposal was the “energy density” that is present in the anti-matter substance, which is around “9 x 1016 (10^16) J/kg.
” This has been estimated to be “1010 (10 billion) times” of the traditional propulsion systems. Also, this is know to emit the highest amount of energy “per unit mass” ever known to man (TheSpaceSite. com, 2009; Erichsen, 2006). It is imperative to understand that at the grass root level an anti-matter rocket is simply a “Newtonian rocket,” which still confines to the laws and rules of Newton as well as to the “Einstein’s theory of special relativity” or speed of light. This propulsion system is estimated to have the “highest predicted efficiency, specific impulse and probably the highest thrust to weight ratio.
” In other words, a total amount of “100 milligrams (1/10 gram)” of this substance will be required to match the total propulsion of the spacecraft. This has also led to introduction of changes in the design of the spacecraft itself. As the name describes, the substance has the particles of the matter it is made up of, but the charge along with “quantum numbers is reversed” or the opposite. It is known that anti-matter does not exist naturally, because if it did it would “annihilate with matter” and an explosion would be form with much greater force than the world has ever experienced.
This also means that anti-matter’s usage requires it to be manufactured first and stored with care so that it does not come into contact with the matter (TheSpaceSite. com, 2009). Once the production and storage has taken place the substance can then be used in the propulsion system. It works by releasing the anti-matter into a “chamber” where it “annihilates” with the matter causing the production of energy in the form of “energetic sub-atomic particles. ” The scientists have two choices to make for the propulsion system, namely “the proton-antiproton or the electron-positron annihilation.
” The second one is considered to be harmful as it is known to produce “high energy gamma rays” which cannot be controlled. The first option is relatively save as it gives birth to charged particles that can be controlled and guided with the magnetic field, this leads to the maximization of “propellant mass. ” However, this process is said to produce less energy than the process that produces gamma rays. Still, the energy produced is much more than the traditional and other methods.
An advantage of using the anti-matter propulsion system is that “heavy reactors” can be eliminated as the response is said to be “spontaneous” in the new systems (TheSpaceSite. com, 2009). The designs suggested by scientists for the anti-matter system are divided into four categories, namely solid core, gas core, plasma core, and beam core. Solid Core is when the “annihilation” is said to take place inside a “solid-core heat exchanger. ” The response is that the hydrogen is heated at a high temperature and is released through a “nozzle.
” This method is said to produce a greater thrust and considered to be highly efficient, but due to the materials that are being used “impulse is only 1000secs at best. ” Gas Core is where the “annihilation” is said to occur in “hydrogen propellant,” and the charged “pions” can be monitored and controlled in the magnetic field, the hydrogen is also heated at a high temperate. Loss is predicted to occur in shape of “gamma rays” which are uncontrollable and the “specific impulse is of 2500secs. ” Annihilation in Plasma Core occurs in large amount to give birth to hot plasma.
This also suffers some loss due to gamma rays, but the plasma in the magnetic fields is said to produce the thrust when it is released. This produces a much higher impulse at “5,000 to 100,000secs” and is said to have “no material constraints. ” Finally, Beam Core is when “direct annihilation” takes place when magnetic field controls the charges “pions” which are then “used directly as the exhausted propellant mass. ” They are said to travel at around light speed with the “impulse greater than 10,000,000secs” (TheSpaceSite. com, 2009).
The usage of this anti-matter propulsion system is said to decrease the time of travel compared to the traditional spacecraft. For example, the traditional spacecraft took 1 to 2 years to reach Mars, whereas this one is said to take from 24 hours to 2 week. The problem however is with the production and the storage of the anti-matter as it can cause heavy explosions (TheSpaceSite. com, 2009; Erichsen, 2006). Arguably the most hypothetical and yet unique propulsion system for space travel in exotic propulsions is the photon propulsion system. The use of photons as a propulsion mechanism is still in the early stages of development and research.
This system achieves the phenomenon of thrust through the expulsion of photons. Governed by Einstein’s famous equation of relativity, E=mc2, photon propulsion requires extremely large quantities of energy to produce a minimal amount of thrust. Some scientist speculate that possibly the obliteration of matter-antimatter may be exploited as a sustainable energy source for photon propulsion (Erichsen, 2006). Interestingly enough photons are neutrally charged. They do not have a positive or negative electric signature. Photons are reasoned to be uncultivable for producing thrust in propulsion (Bhola, 2007).