Fatima Ebrahimi, a physicist from the Princeton Plasma Physics Laboratory (PPPL) at the U.S. Department of Energy’s (DOE) has designed a plasma thruster that is likely to make space travel way faster than any other existing technology.
Fast and efficient space travel has the potential to push mankind towards a better future. There might be planets, resources, and even life forms located far away that can bring a drastic change in our knowledge, understanding, and lifestyle. There are strong chances that, if it turns out to be successful, the new plasma thruster design from Ebrahimi could change the dynamics of space travel.
The principle behind Ebrahimi’s plasma thruster design
The origin of Ebrahimi's plasma thruster concept began in some previous experiments related to doughnut-shaped fusion devices known as tokamaks, which were conducted by researchers at the Princeton Plasma Physics Laboratory.
In 1999, PPPL, in collaboration with Columbia University, Oak Ridge National Laboratory, and the University of Washington, created the National Spherical Torus Experiment (NSTX), a magnetic fusion device based on the tokamak concept. The device has since been upgraded to become the NSTX-U (upgrade) project.
The purpose of the NSTX is to develop a path towards using fusion energy as an abundant, safe, affordable, and environmentally sound means of generating electricity. The NSTX device uses a novel spherical torus-shaped structure to create a magnetic field, which is used to contain hot ionized gas, called plasma, needed to cause a fusion reaction.
Future fusion power plants will use plasmas consisting of a mixture of deuterium and tritium, which would undergo fusion reactions to produce helium, along with a large release of energy. To achieve this, it is necessary to maintain a sufficient temperature and pressure in the plasma while a shaped magnetic field provides insulation.
Theoretically, a spherical torus shape will allow the plasma pressure needed to produce self-sustaining fusion to be maintained with lower magnetic field strength. Since the cost of a fusion power plant will increase with the strength of its magnetic field, a lower magnetic field strength for the plasma confinement could lead to economical fusion power plants.
In an interview, Ebrahimi revealed that she observed the similarities between a car’s exhaust and the high-velocity exhaust particles produced by PPPL’s National Spherical Torus Experiment, and realized that when operational, the tokamak device could make plasma bubbles (plasmoids) which travel at astonishing speeds of around 44730 miles per hour (20 km/sec).
This finding led Ebrahimi to come up with a new plasma thruster design, which uses magnetic field energy to create high thrust. She later published this concept in detail in the Journal of Plasma Physics.
Differences between existing space travel technology and Ebrahimi’s design
There are several differences between Ebrahimi’s concept and other proposals. The first is that the design allows the velocity to be increased or decreased by changing the strength of the magnetic fields. Current plasma thrusters that use electric fields can only produce low specific impulses or speeds.
The new thruster would use the ejection of both plasma particles and plasmoids to produce movement. Ebrahimi's concept is unique in its incorporation of plasmoids, which would add power to the propulsion.
In addition, while current thruster concepts rely on electric fields and heavy gases made of atoms like xenon, the magnetic fields in Ebrahimi’s concept would allow the plasma inside the thruster to consist of almost any type of gas. This would create more flexibility and allow more variation in the amount of thrust.
At present, space travel even to the nearest planet, Mars, will take around seven months. Current rocket engines generate a low specific impulse, which results in low exhaust velocity and so modern-day space ships take time to speed up.
Ebrahimi's plasmoid thruster would be more efficient than the current concepts, partly due to its use of electromagnets to adjust the thrust. The design would allow astronauts to increase or decrease the velocity of their rocket as needed.
Computer simulations of Ebrahimi’s plasma thruster design showed that it can deliver exhaust velocity 10 times higher than the thrusters used at present. For the same reason, this magnetic plasma thruster is now also being seen as an efficient means to send humans to Mars.
Expected impacts of a faster space travel technology
Faster space travel would not only enable us to visit more distant stars and galaxies but is also likely to provide us with more scientific knowledge, resources, and perhaps even economic development. There are many ways in which it can affect mankind:
- An efficient plasma thruster technology like the one proposed by the DOE physicist can significantly reduce the cost of space missions because, with faster rocket engines, space missions would be shorter. The cost of fuel, logistics, etc. would reduce drastically with decreased traveling time.
- Therefore, space and interplanetary transportation might become more feasible than ever before. A decrease in travel time decreases the number of time astronauts would be exposed to dangerous cosmic radiation that permeates any spacecraft. Thus, a plasma thruster that offers great speed can reduce the various health risks involved with human spaceflight programs, and eventually, it would also encourage space agencies to conduct more space missions with human passengers on board.
- Faster space exploration could possibly give a boost to mankind’s search for alien life, more space programs could be launched in a short span of time to explore planets within and perhaps even outside of our galaxy.
- The sole dependence on earth for resources may come to an end with the advent of faster space travel technology. Due to feasible and quick interplanetary travel, scientists would be able to study and experiment on all kinds of matter available to them from different parts of the universe.
- Space travel might also bring advancements in technology and research. A faster and more feasible space travel technology may give rise to new sectors and soon turn hypothetical concepts such and space mining into reality.
While many new developments are yet to happen in space travel technology, Dr. Ebrahimi is optimistic about her reconnector plasmoid thruster design and she hopes to have the first prototype ready soon.
Study: Journal of Plasma Physics
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