Saturday, August 5, 2017

Tribute to Dandridge M. Cole

Dandridge McFarlan  Cole, aeronautical engineer, futurist, lecturer, author. 1921-1965

By W. Raithel

Published in the Annals of the New York Academy of Sciences 140, article 1, December 1966.

Dandridge M. Cole was born on February 19, 1921, in Sandusky, Ohio. He died on October 29, 1965, as a result of a heart attack, less than a week before he was to deliver one of the papers published in this volume. He graduated from Princeton University with the class of 1943 and secured his Master’s degree at the University of Pennsylvania in 1949.

He lived most of his life in Bryn Athyn, a suburb of Philadelphia, and leaves a wife and six children. He wrote poetry and children’s songs and was active in athletics. Between 1945 and 1953, he taught at the Academy of New Church, Phillips Exeter Academy, and the University of Pennsylvania. From 1953 to 1960 he worked for the Martin Company in Baltimore and Denver, after which he completed five years of service with the General Electric Company’s Missile and Space Division at Valley Forge, PA.

He was a director of the American Astronautics Society, a member of the American Institute of Aeronautics and Astronautics, and a Fellow of the British Interplanetary Society.

Dan Cole established an enviable record for himself as a long-range planner and thinker, with a reputation in and beyond the United States. Fortune Magazine, in August of 1964, in an article entitled “The Wild Birds find a Corporate Roost,” described Dan Cole as part of a select group of advance thinkers in industry who have "taken a leaf from Leonardo da Vinci.”
Dan’s many-faceted abilities are shown also by his having been selected by the American Broadcasting Company for a leading role in their national network documentary called “The Way Out Men.”

The British author Arthur C. Clarke believes that most people trying to predict future technical developments are afflicted with either "failure of imagination” or "failure of nerve." Dan had plenty of both: imagination and nerve. In his thoughts he was bold, and without fear to think the unthinkable. In his deeds he was gentle and considerate and never critical of others.

Dan was offered a chance to appear in a series of national advertisements sponsored by a tobacco company extolling the virtues of a well-known cigarette. Despite the large fee, in four figures, and the national exposure, Dan quietly and without fanfare declined, because he did not want to encourage anyone, particularly youths, to start or continue smoking.

Dan was a deeply religious man and said in his book, Beyond Tomorrow, “While no one can say what the future will hold, there are indications that the next fifty years will see the emergence of a new religion with beliefs consistent with the established principles of science. Thus, religion will be affected by the new discoveries regarding behavior and group interactions. It should also profit from the new realization of both scientist and theologian that neither alone has the key to knowledge and happiness, and from the new maturity of mankind.”

His philosophy was perhaps best expressed in the foreword of this book, where he wrote, “While the future holds great stress and threat as well as great challenges, we also see basis for expectations of the growth of man to a state of greater wisdom, greater accomplishment, and greater happiness in the wonderful world beyond tomorrow.”

As a strong individualist, he did not hesitate to speak out on matters he considered important. He might be called on of those of whom Thoreau spoke in his book Walden: “If man does not keep pace with his companions perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured and far away.”

Dan did hear a different drummer. His main contribution was that he caused us to stretch our imagination, caused us to take issue with the increasing rate of change that we are forcing upon ourselves, all too often without much thought as to where we are heading, and he made us realize that the greater the rate of change, the greater the penalty for not thinking boldly enough.

For some time he had been studying artificial hearts and other body organs, which led him to think that by the twenty-first century it should be possible to remove all of the major organs of the abdomen and thorax and replace them with superior artificial components. He even pictured man with all parts of the body, except the brain, replaced by mechanical substitutes.

The asteroids were his favorite subject. He pointed out how slight a change in velocity could cause close-approach asteroids to strike the earth with tremendously destructive effects. For instance, the Arizona meteor crater was formed by a meteor perhaps only 300 feet in diameter, but its explosive energy has been estimated to have been in the order of 30 megatons – comparable with one of the largest bombs known today. The South African meteor, with a diameter of approximately one mile, delivered an equivalent of more than 1,000,000 megatons. He was deeply hurt when, as a result of bringing this to the attention of the public, he was accused of promoting super-bombs. All he had done was to bring a thought to a logical, if unpleasant, conclusion.

He also pointed out that close-approach asteroids are the easiest extraterrestrial targets for soft landing in terms of velocity requirements. Because of the extremely low gravitational fields and escape velocities of these asteroids, the landing problem is reduced to a space rendezvous and docking maneuver. The only reason why the moon will be visited sooner is that the travel time is so much shorter. He showed that, with the present SATURN technology, a manned landing on a close-approach asteroid is a distinct possibility  by mid-1970.

And again Dan thought the unthinkable: Why not capture an asteroid into earth orbit? He showed that for asteroids with favorable orbits the effort to do this would not be at all out of reason, particularly if other planets were used to help make the necessary orbit changes. This possibility was also suggested in a speech by Lyndon B. Johnson in Seattle in 1962.

According to all we know about our solar system and the law of probabilities, a considerable number of asteroids with suitable orbits and suitable sizes must exist. In recent years new asteroids have been discovered and old ones rediscovered, largely by accident. It is surely in some measure a result of Dandridge M. Cole’s work that a systematic search for asteroids has now been undertaken. When a suitable one is found, it would be most fitting that it be named after him.

Saturday, July 22, 2017

Mars: Part 3 Effects of Suspended Dust

by Dr. Robert Duncan-Enzmann 
reproduced from the Enzmann Archives by WKS

Dust particles, ice crystals, and droplets effect capsules designed for unmanned descent, landing, deployment, and subsequent use. Effects recommended for study are as follows:

* Visibility at ultra-violet, optical, and infra-red frequencies as functions of attenuation, scattering, albedo.
* Communications at radio and radar frequencies as functions of attenuation, refraction, and static noises due to the exchange of energy between particles and antenna.
* Physical effects of particles on equipment including erosion, probability of burial by dunes, bearing strength of terrain recently formed by Aeolian-forces.

The behavior of particles in the atmosphere of a planet may be considered first of all from the point of view of forces tending to introduce them to the atmosphere and forces tending to remove them from the atmosphere. Solid particles will most strongly and most immediately effect objects close to, or on the surface of a planet. Forces working to remove particles from an atmosphere are particle-particle collisions or other interactions, which can only be of significance when particles are of sub-micron size or electrically active, particle-particle interactions in media like nuée-ardent where particles are very dense and may average millimeters in extent, and finally, the more important settling in a gravitational field through a viscos atmosphere. The rate of settling is approximated by Stokes law as given below. If the Kaplan atmosphere for Mars is used, settling rates are slightly slower than those for the Earth. If an 80mb atmosphere is used, settling rates through the atmosphere of Mars through the lower troposphere are about 2 ½ to 3 ½ times as long as those for earth. 

(Stokes’ Law: The force of viscosity on a small sphere moving through a viscous fluid is given by:Fd = 6 π η Rv {\displaystyle F_{d}=6\pi \,\eta \,R\,v\,}where:
Fd is the frictional force – known as Stokes' drag – acting on the interface between the fluid and the particle
η is the dynamic viscosity (Some authors use the symbol μ)
R is the radius of the spherical object
v is the flow velocity relative to the object.
In SI units, Fd is given in Newtons, η in Pa·s, R in meters, and v in m/s.)

If wind forces are to be considered in the landing, there are periods during which winds will be at a maximum. These are found when a possible landing site is also the site of the sub-Solar spot or within a few degrees of it. Extreme wind-shear may be expected in the troposphere with movements toward the spot at the surface, and away from the spot toward the tropopause. The least windy times in the path or vicinity of the sub-Solar spot will be in the early morning hours.

If wind forces anticipated are sufficient to force selection of locations where these are to be minimized below a particular value, the following zones should be avoided in the selection of landing sites: 

* The sub-Solar spot.
* The Zone of Trade Winds, which are stronger somewhat south of the Equator, rather than being at a maximum over the Equator.
* The zones of Northern and Southern Westerlies.
* The zones of Northern and Southern Easterlies.

The pandorae-pretum/hellespontus warm thermal anomaly (Lat. 350S Long. 3450) where Easterly cyclonic circulation persists in a belt of prevailing Westerlies. 

In addition to these zonal winds, some effort should be devoted to avoiding a landing in major atmospheric channels, such as that of the Mars Dry Hemisphere, where winds would tend to be stronger than those over the hemisphere from longitude 2700 to longitude 900. Still further precautions may be taken to minimize tropospheric turbulence and buffeting by avoiding regions of severe thermal updraft.

Avoidance of thermal updraft may be somewhat difficult as the areas of maximum biological, geological, topographic, atmospheric, geochemical, etc. interest are the very areas in which updraft would be at a maximum. However, the severity might be reduced by choosing landing sites somewhat in the lee of such prominences.

In general, optimum landing sites, from the point of view of minimum tropospheric turbulence and wind force per unit area subsequent to landing, may be chosen in the Doldrum zones. Within this belt, the lee side of probable topographic anomalies could be further defined.

Interaction of Atmospheres with Lithospheres and Hydrospheres

Interactions may be classified as changes in the atmosphere, and changes in the lithosphere and hydrosphere. Changes in the atmosphere are a result of adding or subtracting substances, changing the size of eddies, changing the kinetics of the atmosphere, and changing the physical parameters of the atmosphere such as temperature, pressure, etc. Changes in the lithosphere are due to erosion, deposition, exchange of matter such as oxygen, nitrogen (usually through the aid of organisms), or carbon dioxide. Changes in the hydrosphere are due to addition of matter via precipitation or solution, subtraction of matter by evaporation or exsolution, friction or pressure-induced currents or changes in levels, and physical changes, particularly heating and cooling.

These processes in the terrestrial environment are understood empirically and, to an extent, analytically. Knowledge concerning the Mars environment is sufficient to provide data which can be manipulated to give at least order of magnitude parameters, which can be refined as more information concerning the environment becomes available.

As detailed in a previous paragraph, only a fraction of the atmosphere of Mars is being considered. This extends from the Stratospheric-zone through the troposphere to the immediate surface. Within this limited vertical section through the atmosphere of Mars, only features which would affect the descent, landing, deployment, and subsequent stability of the unmanned vehicle will be considered. The first of the features considered are those which are not strongly affected by relatively minor surface features.

References for the Mars dust series parts 1-3:
Norman Sissenwine  
F G Finger
M F Harris
S Teweles
Calvin E Anderson
Elmar R Reiter
F G Beuf  
F A Berry  
E Bollay  
Norman Beers  
George Ohring
Owen Cote  
Alden A Loomis  
R S Schorer  
O G Sutton
Gerard Kuiper  
Milton Klein  
Kwang Yu
Richard Harrison
Thomas F Malone
Gerard de Vaucouleurs

Friday, July 14, 2017

Voyage Beyond Apollo, video

Voyage Beyond Apollo video

Apollo 17, The Final NASA Voyage? (Part 1)
Director: Marie Morgan Producer: William Kurchak
Video Production: Timothy Buell

Dr. Robert Duncan-Enzmann's Conference on Planetology and Space Mission Planning aboard the cruise ship Stattendam in 1972.