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.
The energy can be delivered with powerful laser beams! Believe it or not, the original idea was published in 1924 by Konstantin Tsiolkovsky, the space scientist and great visionary, who preceded his own times for at least on half-century. Tsiolkovsky pointed out that energy can be delivered to a space rocket by means of tight light beams (laser was invented 35 years later). The idea of light-beaming energy to a rocket that could be just a dream in 1924, was refined, formulated and delivered by Arthur Kantrowitz as a precise scientific concept of laser propuslion.
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.
Laser-propelled rocket will be made of light focusing optics (mirrors), modest amount of ablative solid fuel, and the rest is a payload. No more need for heavy fuel/oxidizer, tanks, lines, chambers, nozzles! Kantrowitz called it 4P Principle: Payload, Propellant and Photons, Period! Scientifically proven (and repeated in different ways for many times) calculations show that with the laser propulsion space delivery price will be reduced to $100 per pound of a payload! It is hundredfold savings!
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. - 16492
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.
The energy can be delivered with powerful laser beams! Believe it or not, the original idea was published in 1924 by Konstantin Tsiolkovsky, the space scientist and great visionary, who preceded his own times for at least on half-century. Tsiolkovsky pointed out that energy can be delivered to a space rocket by means of tight light beams (laser was invented 35 years later). The idea of light-beaming energy to a rocket that could be just a dream in 1924, was refined, formulated and delivered by Arthur Kantrowitz as a precise scientific concept of laser propuslion.
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.
Laser-propelled rocket will be made of light focusing optics (mirrors), modest amount of ablative solid fuel, and the rest is a payload. No more need for heavy fuel/oxidizer, tanks, lines, chambers, nozzles! Kantrowitz called it 4P Principle: Payload, Propellant and Photons, Period! Scientifically proven (and repeated in different ways for many times) calculations show that with the laser propulsion space delivery price will be reduced to $100 per pound of a payload! It is hundredfold savings!
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. - 16492
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 space technology of the future AIBEP He is also associate professor of physics at University of Alabama in Huntsville. To read more about Arthur Kantrowitz and fascinating field of laser propulsion, please visit official web site of AIBEP.
