| Arthur Kantrowitz passed away on November 29, | | | | the tip of the beam. When laser beam is focused |
| 2008 in New York City. He was 95 years old. A | | | | on a solid surface, it has enough power to |
| founder of Avco Everett Research Laboratories, | | | | vaporize and ionize almost anything with energy |
| inventor of ablative rocket nose cones (reentry | | | | release much higher than hydrogen burning, used |
| protection), champion of Science Court and | | | | in modern space rockets. So, comparing to |
| professor of Dartmouth College, Kantrowitz will | | | | chemical rockets, laser propulsion uses the same |
| be always remembered as a forefront figure of | | | | rocket principle, excepting much more energetic |
| American scientific community of 20th century. | | | | exhaust and much lighter vehicle structure: no |
| However, in this brief note I would like to say | | | | tanks, fuel lines, etc. leaving a lot of room for a |
| few words about one of his greatest | | | | payload. |
| contributions to mankind: his key role in | | | | Laser-propelled rockets will be made of light |
| development of laser propulsion. | | | | focusing optics (mirrors), modest amount of |
| It is rocket science, but forget the silly | | | | ablative solid fuel, and the rest is a payload. No |
| cliché: the idea of laser propulsion is simple. | | | | more need for heavy fuel/oxidizer, tanks, lines, |
| Modern space rockets are too heavy, inefficient, | | | | chambers, nozzles! Kantrowitz called it 4P Principle: |
| and dangerous, because they have to carry their | | | | Payload, Propellant and Photons, Period! |
| fuel and oxidizer onboard. On average they cost | | | | Scientifically proven (and repeated in different |
| us $10,000 per pound of a payload delivered to | | | | ways for many times) calculations show that with |
| low earth orbit. If someone could find a way to | | | | the laser propulsion space delivery price will be |
| separate the energy source from a rocket, which | | | | reduced to $100 per pound of a payload! It is |
| will eliminate all fuel-related burden, the gain in | | | | hundredfold savings! |
| rocket efficiency will be enormous. | | | | The paper of Dr. Kantrowitz from 1972 marked |
| This can be done using energy transfer with laser | | | | the beginning of a new scientific quest. In early |
| beams! This idea was originally formulated in 1924 | | | | seventies Kantrowitz has initiated first research |
| by Konstantin Tsiolkovsky, who believed that | | | | program on laser propulsion at Avco-Everett |
| beams of light could serve as a source of | | | | Research Labs, which for over a decade was the |
| external energy for driving space rockets, that | | | | only research program in this field in the world. |
| removed the burden of fuel onboard and makes | | | | Later other projects ensued, first laser-propelled |
| rocket much lighter, and hence, more efficient. | | | | vehicles were launched (not into space yet, but |
| Tsiolkovsky with his pioneering ideas forerun his | | | | high enough to prove the viability of an idea), |
| time on at least 50 years, Kantrowitz who was 11 | | | | other countries (Russia, Japan, Germany, China) |
| years old in 1924, made his pioneering contribution | | | | and hundreds of scientists and engineers joined |
| just in time. | | | | the quest for laser propulsion (and other forms of |
| In 1972 Kantrowitz published a paper titled | | | | beamed-energy propulsion, such as microwave |
| "Propulsion to Orbit by Ground Based Lasers", | | | | propulsion). However, we should always |
| with a genius idea: to launch light satellites right | | | | remember one man who started it all: Arthur |
| from the ground to space with high-power laser | | | | Kantrowitz, the father of laser propulsion. |
| beams. In this the vehicle will be just "straddling" | | | | |