Rocket Engines: The Influence Within The Solar System
problem Statement
Since the dawn of the space race, man continues to strive towards the heavens. A lot has changed in the past 60 years, which marked the beginning of spaceflight capabilities and operations. With each passing decade, we further our influence within the solar system. From rovers on nearby celestial bodies to probes reaching far past Pluto, we constantly seek to expand on where we can go and what we can do. This drive is propelled by mankind's ingenuity, curiosity, and determination. However, more importantly, our expanding celestial influence is propelled on the backs of rocket engines. In regards to leaving Earth’s atmosphere, rocket engines haven’t undergone any drastic changes since their conception. Generally, rocket engines derive their thrust from a chemical reaction, involving a fuel and an oxidizer. This combination can be applied in liquid or solid form, …show more content…
which will then combust providing the rocket with its momentum. These types of engines require an immense amount of fuel. In fact, nearly 90% of the total weight of the Space Shuttle and external tank, is devoted to fuel. To compensate for the weight, the combustion rocket engine allows for great thrust in a very short amount of time. However, this propulsion method is not efficient when it comes to operations outside of Earth’s atmosphere. If mankind wishes to extend towards other planets, we must seek out different methods for rocket propulsion. Relying on just chemical propulsion would require larger, heavier, and more expensive rockets. This is more specifically, we must rely on new propulsion technologies that can achieve higher specific impulse and are capable of greater speeds.
Background
The concept of thrust in rocket propulsion is very simplistic. Matter is expelled out of a rocket’s nozzle at a high velocity. Each particle places an equal and opposite force on the body that has expelled the particles. These particles have to come from a source of fuel, the fuel that is most commonly used in conventional rockets is petroleum based. This combined with an internal storage of oxygen is then ignited to further accelerate the engine to produce thrust. The petroleum can be expelled and ignited in the form of a liquid or a solid, depending on the rocket engine’s design. Petroleum is most commonly used in rockets, but it isn’t the only means of propulsion. The “Variable Specific Impulse Magnetoplasma Rocket” uses a different means of propellant to provide its thrust.
The “Variable Specific Impulse Magnetoplasma Rocket,” or “VASMIR” for short, was invented by Franklin Chang-Díaz, a graduate from the University of Connecticut in 1973 with a degree in mechanical engineering, and a Doctorate in Applied Plasma Physics from the Massachusetts Institute of Technology from 1977 (“Astronaut Bio”). Mr. Chang-Diaz is now a former astronaut and has also served as the director of the Advanced Space Propulsion Laboratory at the Johnson Space Center. The invention of the Magneto Plasma rocket came from an idea that was thought of during research into a magnetic divertor; a device used to remove waste from plasma in fusion reactors during operation. The magnetoplasma rocket concept began taking shape in the 1970’s in which its completion would be used for NASA’s need for interplanetary transportation.
VASMIR process is taking in gases like Argon, Xenon or even Hydrogen, and ionizing them through the use of a Helicon generator.
This generator produces electromagnetic waves in a helical pattern that knocks electrons loose off of atoms, in order to turn the gas into a cold plasma. The cold plasma can reach temperatures at or above 5800 degrees Kelvin (“Our Engine”). The cold plasma is a mixture of the electrons and the ionized atoms. The shell and components are protected from the intense heat through the use of magnetism. Next stage of VASMIR is utilizing another coupler called the Ion Cyclotron Heating section. Ion Cyclotron Heating utilizes radiofrequency waves to induce cyclotron magnetic resonance heating of ions to a high internal energy (Bering). This internal energy of the atoms can cause the atoms to contain a thermal energy with the temperature of that equivalent to that of the temperatures of the core of the sun. The rocket utilizes a magnetic nozzle to direct the motion of the ions out of the inner chambers of the engine. each ion is propelled at a speed of (112,000
mph).
While all this sounds impressive and great, VASMIR actually produces little thrust. This is because while the internal energies it creates is great, the rocket only expels these ionized particles at a small but constant rate. By itself the rocket couldn’t produce enough thrust to get a rocket out of the earth’s atmosphere. The theoretical idea behind it is that it can be used as a constant means of thrust in an environment where there is very little resistance. In the perfect vacuum, there will be no resistance to provide an opposite force to oppose the rocket’s acceleration. This means that even if the thrust is extremely small but constant, the velocity of the rocket will continue to get faster and faster as long as this constant force is applied. This will allow the rocket to cover interplanetary distances faster and more efficiently than the conventional rocket which uses controlled bursts of thrust to control its speed while trying to conserve as much fuel as possible (“N.S. Company”).
The most beautiful aspect of this rocket's design is the flexibility in the utilization and consolidation of its fuel sources. Mr. Chang-Díaz, said that because the rocket can be fueled using hydrogen, which is one of the universe’s most abundant element, the rocket can theoretically be supplied with just enough fuel to get to mars, arrive at the planet, and collect the hydrogen it needs to make the trip back to earth. He also mentioned that the most optimal source of fuel for the rocket would be nuclear energy. Franklin states that nuclear energy is needed to go to mars, and that NASA’s “Project Prometheus” would be very useful just for this situation. Project Prometheus centers around the idea utilizing nuclear energy as a new source of rocket propulsion fuel. NASA’s Project Prometheus would be able to develop rockets that would get a rocket to mars in the timeframe of two months as opposed to the six months that petroleum based rockets currently achieve (Smith). When it comes to missions that are closer to home, Franklin also says that the rocket can be attached to the International Space Station as a means of course corrections, while being simultaneously powered by the space station’s solar panels.
Technical Discussion
VASIMR ENGINE:
(Ad Astra Rocket Company)
Specific Impulse - the fuel efficiency of a rocket in terms of pounds of thrust per pound of propellant used per second:
The VASIMR engine has much greater fuel efficiency than the main engine of space shuttles, even if the thrust is not nearly as high.
However, because space is a vacuum allowing for rockets to keep increasing speed until they run out of fuel, as opposed to the maximum velocity for flight vehicles on earth that are limited by drag, and the fuel efficiency of the engine is greater, the VASIMR rocket should be able to achieve higher speeds than the combustion engine rockets (Ad Astra Rocket Company).
Conclusion
The goal of many space missions is to expand humankind’s knowledge of the universe, and to accomplish these, there need to be great improvements in capabilities of rockets. One major improvement can be made in rocket engines which consume exorbitantly large amounts of fuel. As of now, one solution appears to be the VASIMR engine. While it only has moderate thrust, it is far more fuel efficient than the combustion engine. Theoretically, it will also be able to reach higher speeds. In fact, it has been predicted that the trip to Mars could be cut down from 250 days to 39 days with such an engine, according to Ad Astra Rocket Company’s founder Franklin Chang-Diaz. This would save not only time, but also space on the rocket for items which are necessary for humans to survive such as food. Thus, the further development of this engine would mean great gains in space exploration.
Suggested Future Research While we have discussed a lot of detail on ion propulsion systems, there are many areas of propulsion that we have yet to cover. VASIMR is certainly one of the closest and most feasible goals we have for cutting costs and time for space travel. However, there are other modes of propulsion that could revolutionize space travel as we know it. One such area of research is nuclear fusion propulsion systems. The goal, is to produce identical or greater thrust of current rocket engines with just a fraction of the fuel (Kelley). This technology would allow for heavier payloads to be used in sending objects to space. A key component in securing a good foundation for future space operations. Nuclear fusion propulsion may be the ticket towards deep space exploration, but research will show how feasible this technology may really be.
Since the dawn of the space race, man continues to strive towards the heavens. A lot has changed in the past 60 years, which marked the beginning of spaceflight capabilities and operations. With each passing decade, we further our influence within the solar system. From rovers on nearby celestial bodies to probes reaching far past Pluto, we constantly seek to expand on where we can go and what we can do. This drive is propelled by mankind's ingenuity, curiosity, and determination. However, more importantly, our expanding celestial influence is propelled on the backs of rocket engines. In regards to leaving Earth’s atmosphere, rocket engines haven’t undergone any drastic changes since their conception. Generally, rocket engines derive their thrust from a chemical reaction, involving a fuel and an oxidizer. This combination can be applied in liquid or solid form, …show more content…
which will then combust providing the rocket with its momentum. These types of engines require an immense amount of fuel. In fact, nearly 90% of the total weight of the Space Shuttle and external tank, is devoted to fuel. To compensate for the weight, the combustion rocket engine allows for great thrust in a very short amount of time. However, this propulsion method is not efficient when it comes to operations outside of Earth’s atmosphere. If mankind wishes to extend towards other planets, we must seek out different methods for rocket propulsion. Relying on just chemical propulsion would require larger, heavier, and more expensive rockets. This is more specifically, we must rely on new propulsion technologies that can achieve higher specific impulse and are capable of greater speeds.
Background
The concept of thrust in rocket propulsion is very simplistic. Matter is expelled out of a rocket’s nozzle at a high velocity. Each particle places an equal and opposite force on the body that has expelled the particles. These particles have to come from a source of fuel, the fuel that is most commonly used in conventional rockets is petroleum based. This combined with an internal storage of oxygen is then ignited to further accelerate the engine to produce thrust. The petroleum can be expelled and ignited in the form of a liquid or a solid, depending on the rocket engine’s design. Petroleum is most commonly used in rockets, but it isn’t the only means of propulsion. The “Variable Specific Impulse Magnetoplasma Rocket” uses a different means of propellant to provide its thrust.
The “Variable Specific Impulse Magnetoplasma Rocket,” or “VASMIR” for short, was invented by Franklin Chang-Díaz, a graduate from the University of Connecticut in 1973 with a degree in mechanical engineering, and a Doctorate in Applied Plasma Physics from the Massachusetts Institute of Technology from 1977 (“Astronaut Bio”). Mr. Chang-Diaz is now a former astronaut and has also served as the director of the Advanced Space Propulsion Laboratory at the Johnson Space Center. The invention of the Magneto Plasma rocket came from an idea that was thought of during research into a magnetic divertor; a device used to remove waste from plasma in fusion reactors during operation. The magnetoplasma rocket concept began taking shape in the 1970’s in which its completion would be used for NASA’s need for interplanetary transportation.
VASMIR process is taking in gases like Argon, Xenon or even Hydrogen, and ionizing them through the use of a Helicon generator.
This generator produces electromagnetic waves in a helical pattern that knocks electrons loose off of atoms, in order to turn the gas into a cold plasma. The cold plasma can reach temperatures at or above 5800 degrees Kelvin (“Our Engine”). The cold plasma is a mixture of the electrons and the ionized atoms. The shell and components are protected from the intense heat through the use of magnetism. Next stage of VASMIR is utilizing another coupler called the Ion Cyclotron Heating section. Ion Cyclotron Heating utilizes radiofrequency waves to induce cyclotron magnetic resonance heating of ions to a high internal energy (Bering). This internal energy of the atoms can cause the atoms to contain a thermal energy with the temperature of that equivalent to that of the temperatures of the core of the sun. The rocket utilizes a magnetic nozzle to direct the motion of the ions out of the inner chambers of the engine. each ion is propelled at a speed of (112,000
mph).
While all this sounds impressive and great, VASMIR actually produces little thrust. This is because while the internal energies it creates is great, the rocket only expels these ionized particles at a small but constant rate. By itself the rocket couldn’t produce enough thrust to get a rocket out of the earth’s atmosphere. The theoretical idea behind it is that it can be used as a constant means of thrust in an environment where there is very little resistance. In the perfect vacuum, there will be no resistance to provide an opposite force to oppose the rocket’s acceleration. This means that even if the thrust is extremely small but constant, the velocity of the rocket will continue to get faster and faster as long as this constant force is applied. This will allow the rocket to cover interplanetary distances faster and more efficiently than the conventional rocket which uses controlled bursts of thrust to control its speed while trying to conserve as much fuel as possible (“N.S. Company”).
The most beautiful aspect of this rocket's design is the flexibility in the utilization and consolidation of its fuel sources. Mr. Chang-Díaz, said that because the rocket can be fueled using hydrogen, which is one of the universe’s most abundant element, the rocket can theoretically be supplied with just enough fuel to get to mars, arrive at the planet, and collect the hydrogen it needs to make the trip back to earth. He also mentioned that the most optimal source of fuel for the rocket would be nuclear energy. Franklin states that nuclear energy is needed to go to mars, and that NASA’s “Project Prometheus” would be very useful just for this situation. Project Prometheus centers around the idea utilizing nuclear energy as a new source of rocket propulsion fuel. NASA’s Project Prometheus would be able to develop rockets that would get a rocket to mars in the timeframe of two months as opposed to the six months that petroleum based rockets currently achieve (Smith). When it comes to missions that are closer to home, Franklin also says that the rocket can be attached to the International Space Station as a means of course corrections, while being simultaneously powered by the space station’s solar panels.
Technical Discussion
VASIMR ENGINE:
(Ad Astra Rocket Company)
Specific Impulse - the fuel efficiency of a rocket in terms of pounds of thrust per pound of propellant used per second:
The VASIMR engine has much greater fuel efficiency than the main engine of space shuttles, even if the thrust is not nearly as high.
However, because space is a vacuum allowing for rockets to keep increasing speed until they run out of fuel, as opposed to the maximum velocity for flight vehicles on earth that are limited by drag, and the fuel efficiency of the engine is greater, the VASIMR rocket should be able to achieve higher speeds than the combustion engine rockets (Ad Astra Rocket Company).
Conclusion
The goal of many space missions is to expand humankind’s knowledge of the universe, and to accomplish these, there need to be great improvements in capabilities of rockets. One major improvement can be made in rocket engines which consume exorbitantly large amounts of fuel. As of now, one solution appears to be the VASIMR engine. While it only has moderate thrust, it is far more fuel efficient than the combustion engine. Theoretically, it will also be able to reach higher speeds. In fact, it has been predicted that the trip to Mars could be cut down from 250 days to 39 days with such an engine, according to Ad Astra Rocket Company’s founder Franklin Chang-Diaz. This would save not only time, but also space on the rocket for items which are necessary for humans to survive such as food. Thus, the further development of this engine would mean great gains in space exploration.
Suggested Future Research While we have discussed a lot of detail on ion propulsion systems, there are many areas of propulsion that we have yet to cover. VASIMR is certainly one of the closest and most feasible goals we have for cutting costs and time for space travel. However, there are other modes of propulsion that could revolutionize space travel as we know it. One such area of research is nuclear fusion propulsion systems. The goal, is to produce identical or greater thrust of current rocket engines with just a fraction of the fuel (Kelley). This technology would allow for heavier payloads to be used in sending objects to space. A key component in securing a good foundation for future space operations. Nuclear fusion propulsion may be the ticket towards deep space exploration, but research will show how feasible this technology may really be.