Artur Kantrowitz, a prominent American scientist of late twentieth century, died in age of 95 in New York City on November 29, 2008. Founder of Avco Everett Research Labs, professor of Dartmouth College, champion of Science Court and versatile inventor, he will be always remembered. In this short note I just like to say a word about one of his greatest ideas and contributions to society, which will benefit future generations of our planet. I am talking about his role in founding of laser propulsion.
Laser Propulsion is a part of advanced rocket science, but the concept is so simple, that you dont have to be a rocket scientist to grasp it. Do you know that on average we pay ten grand per every pound of a payload delivered to low earth orbit. Sounds a bit pricey. Unfortunately, we have no choice, because the only way to deliver that pound is to use a rocket, hydrogen (mainly) burning tube (most sophisticated in modern technology), filled with fuel, oxidizer, cryogenics, tanks, lines, etc. with a little room for a cargo. It is inefficient to carry all fuel onboard, and so is the price. If only we could separate the source of burning energy from the vehicle, deliver this energy from outside, the savings on weight and efficiency will be dramatic.
The energy can be beamed to the rocket with powerful lasers! The original idea on beaming energy to a space rocket was invented by Konstantin Tsiolkovsky in 1924. Genius and visionary, Tsiolkovsky could not know about lasers (the first laser was demonstrated in 1960), so he was talking about tight beams of light, beamed to a rocket and hence providing it with necessary energy or, in other words, making the rocket much more energy efficient. In 1924 all this was just a dream, a few decades later Arthur Kantrowitz presented the world with scientifically sound plan for turning this dream into reality.
In 1972 Arthur Kantrowitz published in Astronautics and Aeronautics Propulsion to Orbit by Ground Based Lasers, a scientific paper which started a new field: laser propulsion. In this paper Kantrowitz proposed to change our very approach to space launches: instead of building larger (and even less energy-efficient rockets), start using high-power lasers for space launches of small satellites. Such satellites would literally straddle the tip of laser beam, focused on their propellant area. When high power laser beam is focused (even loosely) on a solid matter, such matter is evaporated and ionized almost instantaneously, i.e. the release of energy is much higher than one used from burning hydrogen in rockets. So, laser-driven vehicle will be still flying on the same rocket principle, but exhaust energy and structural lightness will be incomparably superior to hydrogen-burning rockets.
Driven by laser rocket will be composed of very light focusing mirrors, relatively small (energy efficient) solid propellant and, voila: the rest will be payload! Forget heavy liquefied gases (oxygen and hydrogen), cryogenics, fuel tanks and lines, combustion chambers, etc.: Payload, Propellant and Photons, Period! Arthur Kantrowitz called it 4P Rule. Bottom line: scientifically sound calculations have shown that the price of one pound of a payload delivered to low earth orbit will be drop to $100. Laser propulsion offers 100-fold, revolutionary savings on space deliveries.
The original paper of Kantrowitz was like a first milestone at the beginning of a long way, a scientific quest for beamed-energy propulsion. Kantrowitz not mere wrote a fundamental paper, he started the first in the world research program on laser propulsion at Avco Everett Research Labs. Decade later new research projects followed the cause and two decades later first laser-driven vehicles were launched into air (but not to space yet). New countries: Russia, Japan, Germany, China opened their own research programs and hundreds of researchers joined the field. New forms for beamed-energy propulsion were found, such as microwave propulsion. Hundreds of people work on this field today, the work is in progress, there is still a lot to do. Remarkably, this field was opened by one man, Arthur Kantrowitz, and he will be always remembered for that.
Laser Propulsion is a part of advanced rocket science, but the concept is so simple, that you dont have to be a rocket scientist to grasp it. Do you know that on average we pay ten grand per every pound of a payload delivered to low earth orbit. Sounds a bit pricey. Unfortunately, we have no choice, because the only way to deliver that pound is to use a rocket, hydrogen (mainly) burning tube (most sophisticated in modern technology), filled with fuel, oxidizer, cryogenics, tanks, lines, etc. with a little room for a cargo. It is inefficient to carry all fuel onboard, and so is the price. If only we could separate the source of burning energy from the vehicle, deliver this energy from outside, the savings on weight and efficiency will be dramatic.
The energy can be beamed to the rocket with powerful lasers! The original idea on beaming energy to a space rocket was invented by Konstantin Tsiolkovsky in 1924. Genius and visionary, Tsiolkovsky could not know about lasers (the first laser was demonstrated in 1960), so he was talking about tight beams of light, beamed to a rocket and hence providing it with necessary energy or, in other words, making the rocket much more energy efficient. In 1924 all this was just a dream, a few decades later Arthur Kantrowitz presented the world with scientifically sound plan for turning this dream into reality.
In 1972 Arthur Kantrowitz published in Astronautics and Aeronautics Propulsion to Orbit by Ground Based Lasers, a scientific paper which started a new field: laser propulsion. In this paper Kantrowitz proposed to change our very approach to space launches: instead of building larger (and even less energy-efficient rockets), start using high-power lasers for space launches of small satellites. Such satellites would literally straddle the tip of laser beam, focused on their propellant area. When high power laser beam is focused (even loosely) on a solid matter, such matter is evaporated and ionized almost instantaneously, i.e. the release of energy is much higher than one used from burning hydrogen in rockets. So, laser-driven vehicle will be still flying on the same rocket principle, but exhaust energy and structural lightness will be incomparably superior to hydrogen-burning rockets.
Driven by laser rocket will be composed of very light focusing mirrors, relatively small (energy efficient) solid propellant and, voila: the rest will be payload! Forget heavy liquefied gases (oxygen and hydrogen), cryogenics, fuel tanks and lines, combustion chambers, etc.: Payload, Propellant and Photons, Period! Arthur Kantrowitz called it 4P Rule. Bottom line: scientifically sound calculations have shown that the price of one pound of a payload delivered to low earth orbit will be drop to $100. Laser propulsion offers 100-fold, revolutionary savings on space deliveries.
The original paper of Kantrowitz was like a first milestone at the beginning of a long way, a scientific quest for beamed-energy propulsion. Kantrowitz not mere wrote a fundamental paper, he started the first in the world research program on laser propulsion at Avco Everett Research Labs. Decade later new research projects followed the cause and two decades later first laser-driven vehicles were launched into air (but not to space yet). New countries: Russia, Japan, Germany, China opened their own research programs and hundreds of researchers joined the field. New forms for beamed-energy propulsion were found, such as microwave propulsion. Hundreds of people work on this field today, the work is in progress, there is still a lot to do. Remarkably, this field was opened by one man, Arthur Kantrowitz, and he will be always remembered for that.
About the Author:
Dr. Andrew Pakhomov is founder and president of American Institute of Beamed Energy Propulsion, a nonprofit society serving to development and popularization of this advanced space technology AIBEP He is also associate professor of physics at University of Alabama in Huntsville. To read more about Prof. Kantrowitz and fascinating field of beamed-energy propulsion, please visit official site of AIBEP.
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