Interstellar travel is the travel between stars, either in a manned spacecraft or an unmanned spacecraft. There have been many theoretical approaches to this concept. There is a possibility of an unmanned travel but the concept of manned travel will take time to kick off because of the difficulties and the travel time involved. Here we discuss the possibilities and the pros and cons of Interstellar Travel.
Interstellar travel has been the subject of discussion for decades. Science fiction always showed us the way of interstellar travel but these are still fiction. Warp Drives and hyperspace Engines have been the fantasy for the readers of science fiction literature and cinema, but still remain a fantasy. The practical implementation of these devices still isnt in the reach of todays technology and requires far more advanced levels of science and technology.
In the science fiction literature there have been methods where the scientists used generation-ships for interstellar travel. These mean that the crew of the ship lived and die on board and one of the generations will reach the destination. There have been theories where this was stated to be possible but at present is still a distant dream. This is mainly due to the difficulties involved in staying in the space for a large amount of time and the effects of those travels on human health.
There also have been theories that stated the use of concepts such as travelling in sleeper ships. These ships have a mechanism in which the travellers are put in a state of suspended animation. Suspended animation means that the passengers will be put in an inert state and will be put to rest. The maneuvering of the ship will be done by the computers on board. Once the ship reaches the destination, these people will be awakened with their age remaining the same since they started the journey.
All these theories still lack logic because there is no way for a human to be put in a state of suspended animation. The level of technology that is required to do that is still not reached. There have been numerous scientists who have written various papers on this matter and most of the papers still state that manned interstellar travel is still a dream. There is a possibility to achieve the goal by increasing the speed of the spacecraft.
Increasing the spacecraft speed would require the use of advanced propelling systems. There has been a good amount of research done on the concept of the use of nuclear engines. But the dangers posed by the nuclear radiation just are too damaging to even think of using such a mechanism. Even by the use of these engines and other technological advancements interstellar travel still will take years of time larger than a single human life span.
There have been many probes to the distant planets of the solar system such as Uranus and to the dwarf planets such as Pluto. These have taken considerable amount of time and some space crafts have stopped functioning before they reached the boundaries of the solar system.
One must then think of the pros and cons before such a travel is attempted. There may be the possibility of an unmanned probe. The nearest star to the solar system is the Proxima Centauri. This is about 4.3 light years away from the solar system. The fastest ever outward probe was Voyager I. this is now moving at a speed of 10.5 milessec away from the solar system. This is about 118,000 times the speed of light.
Voyager I was launched about 32 years ago in September 1977. As of August 28th 09, this craft is about 10.312 billion miles away from the sun. This is 110.94 Astronomical Units. At this speed the journey to the nearest star Proxima Centauri will take about 72,000 years. This spans a 1000 generations and is virtually impossible at the technology that we have. This journey can be reduced by the use of nuclear pulse propulsion.
Nuclear pulse propulsion is a theoretical concept that is still to be tested in a large scale. Nuclear pulse propulsion is achieved by having a series of nuclear explosions at the rear of the space craft that would accelerate the space craft to really high speeds, as much as 5.4107 kmhr. this is 5 of the speed of the light. At this rate of acceleration the space ship would be subjected to high G-Forces. This will virtually not sustainable by man.
There was a project that was designed by NASA called Project Orion. This was based on the nuclear pulse propulsion technology. There are three types of nuclear pulse propulsion systems. One is thermonuclear Pulse propulsion, second is the atomic fission pulse propulsion. The third is the Matter-Antimatter Pulse propulsion, which is completely a theoretical concept.
The thermonuclear fission can reach speeds up to 8-10 of the speed of light. The atomic pulse propulsion will reach up to 3-5 of the speed of light. The theoretical matter-antimatter drives can achieve 50-80 of the speed of light. The speeds at which this propulsion system can accelerate the craft are very high. The thermonuclear Pulse propulsion can reach Proxima Centauri which is at a distance of 4.23 light years in 44 years. Here is a table that shows the distances of the nearest stars from our solar system.
The Orion spacecraft was designed in a manner where small nuclear explosives were shot from the rear of the spacecraft and exploded about 30m behind. The explosion energy provided momentum to the spacecraft pusher plate. This pusher plate was coated with graphite oil to prevent damage. The pusher plate then transferred the momentum to the shock absorbers that transformed the sudden push to a gentle push that gave the ship 1g acceleration.
This design was lauded and criticized by many. The main problem this design faced was nuclear fallout. This was due to the radioactive debris that will fly out of the rear of the spacecraft that will spread in all directions in the space. This was the most serious of all problems. There were many theoretical propositions that claimed to reduce the fallout to negligible levels, but none could be tested anywhere near the vicinity of the earth.
Fig SEQ Figure ARABIC 1 Orion Space Craft
The Project was apparently called off due to the signing of the PTBT (Partial test ban treaty). There were more projects that were thought of. These include Project Daedalus and Project Longshot. But these projects never passed the drawing board and are still on paper. These require significant advances in technology and science.
Project Daedalus required advanced technology and Project Longshot was designed using the present technology and used Nuclear Fission Reactor for the propelling system, and was slated to achieve speeds up to 4.5 of the speed of light and was slated to reach Alpha Centauri B in about 100 years. The project has its own issues due to the use of nuclear fuel. If there is a way that will minimize the radiations and their effects or even nullify them, we have a really great way of utilizing the nuclear weapons in a constructive manner.
Fig2 An artists conception of the British Interplanetary Society design for Project Daedalus
There have been many debates as to whether the interstellar probes are really necessary especially with their long travel durations (at todays technology) and the significant problems these probes present. There may be a case where a probe is launched with todays technology and might be overtaken by a later probe that will be launched with significantly advanced technology.
There are debates which state that a probe that cant reach the destination in 50 years or less should not be started at all. This is partially correct because if there is a significant technological advancement in the future that may overtake a present probe, the older probe will be rendered useless. This involves millions of dollars of investment. So scientists advocate the design and implementation of better propelling systems with the investment of those dollars rather than sending a space craft on a mission that will take thousands or hundreds of years to reach its destination.
The discoveries that an interstellar probe may find are many. But considering the difficulties in the launching and deployment of the space craft, the investment of the money in designing a better space craft might sound better. This is because there are more space explorations that are more interesting and plausible than an interstellar probe. Seriously an interstellar probe at this time and with this technology is a little awkward. If we can wait for a few more years, the advancements in the technology will enable us to build better systems and perhaps the problems can be solved effectively.
Interstellar travel is certainly possible, but with the current technology a manned mission is impossible and an unmanned probe may take many years to finish the journey. NASA is trying to do some important research space ship that uses the Light Sails as the propelling systems. This technology is of great importance and has lot of advantages. This may be the future of the propelling space crafts into space in the near future.
Geoffery A. Landis, of NASAs Glenn Research Center, says that a laser-powered interstellar space craft that uses light sails could possibly be developed within fifty years, using new methods of space travel. I think that ultimately were going to do it, its just a question of when and who Landis said in an interview. Rockets are too slow to send humans on interstellar missions. Instead, he envisions interstellar craft with gigantic sails, propelled by laser light to about one-tenth the speed of light. It would take such a ship about 43 years to reach Alpha Centauri, if it passed through the system. Slowing down to stop at Alpha Centauri could increase the trip to 100 years.
The goal of the future interstellar probes must be to seek greater knowledge of the universe and to use that knowledge in a constructive manner. These probes must also try to find any planet that can harbor life, just like our earth and they must look for any Extra Terrestrial Intelligence. This will help our cause and will usher us into a new era of space technology.
Just few decades ago, a trip to America from Australia could take well about 9-13 months via the sea route. Now it is scaled down to the matter of hours by aircrafts. People then only had the dream to fly, but wright brothers made it a reality. People also ridiculed the thought of sending satellites into the earth orbit. But now that is a common phenomenon. Science has answered each and every problem of man in a way it could. It is up to us to use the science in greater interest of mankind.
Similarly space travel can seem a bit ridiculous now, but as they say history repeats itself, we might just see NASA or a combined effort of the space competitors launch a manned mission to Alpha Centauri in a few decades. The problems space travel poses are many. There has to be a way man can endure the un-earthly life during the journey and in the alien atmosphere of the destination.
There will also be a way that will reduce the round-trip delay of information transmission. For suppose we reached Alpha Centauri, an information broadcasted there will take 4.23 years to reach the earth. There may be lot of changes that might have to be made in order reduce the time.
There also has been a wide spread discussion on the near light speed travel. Travelling faster than the light is theoretically impossible and will violate the laws of physics. Near light speed has been achieved in particle accelerators in CERN. Those particles are sub-atomic particles like positrons and electrons. These accelerators require lot of energy and investment. Translation of that acceleration to larger bodies like space crafts is impossible now.
But as science and scientists have been repeatedly turning possible to impossible, we can hope that this problem is resolved and we can also travel into space in lesser time and greater payloads can be taken along. It may be a few centuries away where we can start to colonize the outer space and start living there, but as of now it is only possible in dreams and in fiction.
This does not mean we cant send an unmanned probe to the nearest star at this point of time. We have achieved travel to Pluto and further regions of space and Voyager-I is already in the far end region in the solar system. It is scheduled to travel out of the solar system in a few years. This has been achieved in a few years (the craft was launched in 1977).
Use of Artificial Intelligence is a big plus in the Interstellar probes. If we achieve the propelling system that can be used to travel in lesser time, we can use Robots to control the equipment and to transfer the data. The problem faced with unmanned travel is the time that will take to transmit the information from the destination. Project Longshot had this vision. A report from the project stated that
Due to the great distance at which the probe will operate, positive control from earth will be impossible due to the great time delays involved. This fact necessitates that the probe be able to think for itself. In order to accomplish this, advances will be required in two related but separate fields, artificial intelligence and computer hardware. AI research is advancing at a tremendous rate. Progress during the last decade has been phenomenal and there is no reason to expect it to slow any time soon. Therefore, it should possible to design a system with the required intelligence by the time that this mission is expected to be 1aunched.
This report was written way back in the late 80s. There has been a significant advance in the area of artificial intelligence and we might soon see an advanced version of project Longshot being launched. This will require a way to minimize the effects of nuclear radioactive radiation and wastes. Nuclear fusion can be an answer to this, but controlled nuclear fusion isnt still achieved on such a large scale. However the rate at which the technology is advancing we can say proudly that interstellar travel is just a matter of a few more decades.
Interstellar travel has been the subject of discussion for decades. Science fiction always showed us the way of interstellar travel but these are still fiction. Warp Drives and hyperspace Engines have been the fantasy for the readers of science fiction literature and cinema, but still remain a fantasy. The practical implementation of these devices still isnt in the reach of todays technology and requires far more advanced levels of science and technology.
In the science fiction literature there have been methods where the scientists used generation-ships for interstellar travel. These mean that the crew of the ship lived and die on board and one of the generations will reach the destination. There have been theories where this was stated to be possible but at present is still a distant dream. This is mainly due to the difficulties involved in staying in the space for a large amount of time and the effects of those travels on human health.
There also have been theories that stated the use of concepts such as travelling in sleeper ships. These ships have a mechanism in which the travellers are put in a state of suspended animation. Suspended animation means that the passengers will be put in an inert state and will be put to rest. The maneuvering of the ship will be done by the computers on board. Once the ship reaches the destination, these people will be awakened with their age remaining the same since they started the journey.
All these theories still lack logic because there is no way for a human to be put in a state of suspended animation. The level of technology that is required to do that is still not reached. There have been numerous scientists who have written various papers on this matter and most of the papers still state that manned interstellar travel is still a dream. There is a possibility to achieve the goal by increasing the speed of the spacecraft.
Increasing the spacecraft speed would require the use of advanced propelling systems. There has been a good amount of research done on the concept of the use of nuclear engines. But the dangers posed by the nuclear radiation just are too damaging to even think of using such a mechanism. Even by the use of these engines and other technological advancements interstellar travel still will take years of time larger than a single human life span.
There have been many probes to the distant planets of the solar system such as Uranus and to the dwarf planets such as Pluto. These have taken considerable amount of time and some space crafts have stopped functioning before they reached the boundaries of the solar system.
One must then think of the pros and cons before such a travel is attempted. There may be the possibility of an unmanned probe. The nearest star to the solar system is the Proxima Centauri. This is about 4.3 light years away from the solar system. The fastest ever outward probe was Voyager I. this is now moving at a speed of 10.5 milessec away from the solar system. This is about 118,000 times the speed of light.
Voyager I was launched about 32 years ago in September 1977. As of August 28th 09, this craft is about 10.312 billion miles away from the sun. This is 110.94 Astronomical Units. At this speed the journey to the nearest star Proxima Centauri will take about 72,000 years. This spans a 1000 generations and is virtually impossible at the technology that we have. This journey can be reduced by the use of nuclear pulse propulsion.
Nuclear pulse propulsion is a theoretical concept that is still to be tested in a large scale. Nuclear pulse propulsion is achieved by having a series of nuclear explosions at the rear of the space craft that would accelerate the space craft to really high speeds, as much as 5.4107 kmhr. this is 5 of the speed of the light. At this rate of acceleration the space ship would be subjected to high G-Forces. This will virtually not sustainable by man.
There was a project that was designed by NASA called Project Orion. This was based on the nuclear pulse propulsion technology. There are three types of nuclear pulse propulsion systems. One is thermonuclear Pulse propulsion, second is the atomic fission pulse propulsion. The third is the Matter-Antimatter Pulse propulsion, which is completely a theoretical concept.
The thermonuclear fission can reach speeds up to 8-10 of the speed of light. The atomic pulse propulsion will reach up to 3-5 of the speed of light. The theoretical matter-antimatter drives can achieve 50-80 of the speed of light. The speeds at which this propulsion system can accelerate the craft are very high. The thermonuclear Pulse propulsion can reach Proxima Centauri which is at a distance of 4.23 light years in 44 years. Here is a table that shows the distances of the nearest stars from our solar system.
The Orion spacecraft was designed in a manner where small nuclear explosives were shot from the rear of the spacecraft and exploded about 30m behind. The explosion energy provided momentum to the spacecraft pusher plate. This pusher plate was coated with graphite oil to prevent damage. The pusher plate then transferred the momentum to the shock absorbers that transformed the sudden push to a gentle push that gave the ship 1g acceleration.
This design was lauded and criticized by many. The main problem this design faced was nuclear fallout. This was due to the radioactive debris that will fly out of the rear of the spacecraft that will spread in all directions in the space. This was the most serious of all problems. There were many theoretical propositions that claimed to reduce the fallout to negligible levels, but none could be tested anywhere near the vicinity of the earth.
Fig SEQ Figure ARABIC 1 Orion Space Craft
The Project was apparently called off due to the signing of the PTBT (Partial test ban treaty). There were more projects that were thought of. These include Project Daedalus and Project Longshot. But these projects never passed the drawing board and are still on paper. These require significant advances in technology and science.
Project Daedalus required advanced technology and Project Longshot was designed using the present technology and used Nuclear Fission Reactor for the propelling system, and was slated to achieve speeds up to 4.5 of the speed of light and was slated to reach Alpha Centauri B in about 100 years. The project has its own issues due to the use of nuclear fuel. If there is a way that will minimize the radiations and their effects or even nullify them, we have a really great way of utilizing the nuclear weapons in a constructive manner.
Fig2 An artists conception of the British Interplanetary Society design for Project Daedalus
There have been many debates as to whether the interstellar probes are really necessary especially with their long travel durations (at todays technology) and the significant problems these probes present. There may be a case where a probe is launched with todays technology and might be overtaken by a later probe that will be launched with significantly advanced technology.
There are debates which state that a probe that cant reach the destination in 50 years or less should not be started at all. This is partially correct because if there is a significant technological advancement in the future that may overtake a present probe, the older probe will be rendered useless. This involves millions of dollars of investment. So scientists advocate the design and implementation of better propelling systems with the investment of those dollars rather than sending a space craft on a mission that will take thousands or hundreds of years to reach its destination.
The discoveries that an interstellar probe may find are many. But considering the difficulties in the launching and deployment of the space craft, the investment of the money in designing a better space craft might sound better. This is because there are more space explorations that are more interesting and plausible than an interstellar probe. Seriously an interstellar probe at this time and with this technology is a little awkward. If we can wait for a few more years, the advancements in the technology will enable us to build better systems and perhaps the problems can be solved effectively.
Interstellar travel is certainly possible, but with the current technology a manned mission is impossible and an unmanned probe may take many years to finish the journey. NASA is trying to do some important research space ship that uses the Light Sails as the propelling systems. This technology is of great importance and has lot of advantages. This may be the future of the propelling space crafts into space in the near future.
Geoffery A. Landis, of NASAs Glenn Research Center, says that a laser-powered interstellar space craft that uses light sails could possibly be developed within fifty years, using new methods of space travel. I think that ultimately were going to do it, its just a question of when and who Landis said in an interview. Rockets are too slow to send humans on interstellar missions. Instead, he envisions interstellar craft with gigantic sails, propelled by laser light to about one-tenth the speed of light. It would take such a ship about 43 years to reach Alpha Centauri, if it passed through the system. Slowing down to stop at Alpha Centauri could increase the trip to 100 years.
The goal of the future interstellar probes must be to seek greater knowledge of the universe and to use that knowledge in a constructive manner. These probes must also try to find any planet that can harbor life, just like our earth and they must look for any Extra Terrestrial Intelligence. This will help our cause and will usher us into a new era of space technology.
Just few decades ago, a trip to America from Australia could take well about 9-13 months via the sea route. Now it is scaled down to the matter of hours by aircrafts. People then only had the dream to fly, but wright brothers made it a reality. People also ridiculed the thought of sending satellites into the earth orbit. But now that is a common phenomenon. Science has answered each and every problem of man in a way it could. It is up to us to use the science in greater interest of mankind.
Similarly space travel can seem a bit ridiculous now, but as they say history repeats itself, we might just see NASA or a combined effort of the space competitors launch a manned mission to Alpha Centauri in a few decades. The problems space travel poses are many. There has to be a way man can endure the un-earthly life during the journey and in the alien atmosphere of the destination.
There will also be a way that will reduce the round-trip delay of information transmission. For suppose we reached Alpha Centauri, an information broadcasted there will take 4.23 years to reach the earth. There may be lot of changes that might have to be made in order reduce the time.
There also has been a wide spread discussion on the near light speed travel. Travelling faster than the light is theoretically impossible and will violate the laws of physics. Near light speed has been achieved in particle accelerators in CERN. Those particles are sub-atomic particles like positrons and electrons. These accelerators require lot of energy and investment. Translation of that acceleration to larger bodies like space crafts is impossible now.
But as science and scientists have been repeatedly turning possible to impossible, we can hope that this problem is resolved and we can also travel into space in lesser time and greater payloads can be taken along. It may be a few centuries away where we can start to colonize the outer space and start living there, but as of now it is only possible in dreams and in fiction.
This does not mean we cant send an unmanned probe to the nearest star at this point of time. We have achieved travel to Pluto and further regions of space and Voyager-I is already in the far end region in the solar system. It is scheduled to travel out of the solar system in a few years. This has been achieved in a few years (the craft was launched in 1977).
Use of Artificial Intelligence is a big plus in the Interstellar probes. If we achieve the propelling system that can be used to travel in lesser time, we can use Robots to control the equipment and to transfer the data. The problem faced with unmanned travel is the time that will take to transmit the information from the destination. Project Longshot had this vision. A report from the project stated that
Due to the great distance at which the probe will operate, positive control from earth will be impossible due to the great time delays involved. This fact necessitates that the probe be able to think for itself. In order to accomplish this, advances will be required in two related but separate fields, artificial intelligence and computer hardware. AI research is advancing at a tremendous rate. Progress during the last decade has been phenomenal and there is no reason to expect it to slow any time soon. Therefore, it should possible to design a system with the required intelligence by the time that this mission is expected to be 1aunched.
This report was written way back in the late 80s. There has been a significant advance in the area of artificial intelligence and we might soon see an advanced version of project Longshot being launched. This will require a way to minimize the effects of nuclear radioactive radiation and wastes. Nuclear fusion can be an answer to this, but controlled nuclear fusion isnt still achieved on such a large scale. However the rate at which the technology is advancing we can say proudly that interstellar travel is just a matter of a few more decades.
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