Arthur Kantrowitz passed away on November 29, 2008 in New York City. He was 95 years old. A founder of Avco Everett Research Laboratories, inventor of ablative rocket nose cones (reentry protection), champion of Science Court and professor of Dartmouth College, Kantrowitz will be always remembered as a forefront figure of American scientific community of 20th century. However, in this brief note I would like to say few words about one of his greatest contributions to mankind: his key role in development of laser propulsion.
Laser Propulsion is a part of rocket science, but dont be discouraged by a silly tag: the idea is simple. We pay on average $10,000 per every pound of payload delivered to low earth orbit. Why that much? Because, we use very inefficient carriers: chemical rockets. These hydrogen gluttons have to carry everything onboard: fuel, oxidizer, cryogenics, tanks, lines, you name it, leaving a small (and very expensive room) for the payload. If we could only find a way to separate the energy source from the vehicle, deliver that energy to the vehicle from some power station, the gain in efficiency of such vehicle will be tremendous.
This can be done using energy transfer with laser beams! This idea was originally formulated in 1924 by Konstantin Tsiolkovsky, who believed that beams of light could serve as a source of external energy for driving space rockets, that removed the burden of fuel onboard and makes rocket much lighter, and hence, more efficient. Tsiolkovsky with his pioneering ideas forerun his time on at least 50 years, Kantrowitz who was 11 years old in 1924, made his pioneering contribution just in time.
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.
Payload, Propellant, Photons, Period! " 4P Principle introduced by Kantrowitz was an essence of laser propulsion. Laser-driven vehicles will consist of lightweight focusing optics (mirrors), modest amount of solid ablative propellant and the rest: the rest will be payload! No more fuel, cryogenics, tanks, combustion chambers. As a result, scientifically-proven calculations have shown that the price of space delivery per pound will drop from $10,000 (hydrogen "burning rockets) to a modest $100 (laser-driven rockets): a hundredfold, revolutionary change in price!
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. - 15437
Laser Propulsion is a part of rocket science, but dont be discouraged by a silly tag: the idea is simple. We pay on average $10,000 per every pound of payload delivered to low earth orbit. Why that much? Because, we use very inefficient carriers: chemical rockets. These hydrogen gluttons have to carry everything onboard: fuel, oxidizer, cryogenics, tanks, lines, you name it, leaving a small (and very expensive room) for the payload. If we could only find a way to separate the energy source from the vehicle, deliver that energy to the vehicle from some power station, the gain in efficiency of such vehicle will be tremendous.
This can be done using energy transfer with laser beams! This idea was originally formulated in 1924 by Konstantin Tsiolkovsky, who believed that beams of light could serve as a source of external energy for driving space rockets, that removed the burden of fuel onboard and makes rocket much lighter, and hence, more efficient. Tsiolkovsky with his pioneering ideas forerun his time on at least 50 years, Kantrowitz who was 11 years old in 1924, made his pioneering contribution just in time.
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.
Payload, Propellant, Photons, Period! " 4P Principle introduced by Kantrowitz was an essence of laser propulsion. Laser-driven vehicles will consist of lightweight focusing optics (mirrors), modest amount of solid ablative propellant and the rest: the rest will be payload! No more fuel, cryogenics, tanks, combustion chambers. As a result, scientifically-proven calculations have shown that the price of space delivery per pound will drop from $10,000 (hydrogen "burning rockets) to a modest $100 (laser-driven rockets): a hundredfold, revolutionary change in price!
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. - 15437
About the Author:
Dr. Andrew Pakhomov is founder and president of American Institute of Beamed Energy Propulsion, a nonprofit 501(c)(3) corporation 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 laser propulsion, please visit official site of AIBEP.
