. Harry Harrison named the anthology Deathworlds inherently referencing his Deathworld. My story was on a nearly fatal first manned expedition to the icecap of Mercury. Written within days of radar indicating that Mercury has icecaps. My nonfiction on that was praised by Sir Arthur C. Clarke: HUMAN AND ROBOTIC PRECURSOR MISSIONS TO THE POLAR ICECAPS OF MERCURY Jonathan Vos Post* Computer Futures Inc. Abstract Since Caltech/JPL observations suggest possible water ice at the north and south poles of the planet Mercury, it is now feasible to consider a new class of human exploration missions to these sites, and three classes of robotic precursor missions that would precede human exploration (impact/ orbital spectroscopy, lander, sample-return). Mercury polar ice could provide neutrino detection opportunities and would provide in situ resources for refueling spacecraft for return to Earth. I. Introduction and Background Recent astonishing radar observations of the planet Mercury by Bryan Butler (grad student at Caltech), Dr. Raymond Jurgens and Dr. Martin Slade of NASA/JPL, suggest that the innermost planet Mercury may have patches of ice at its poles.1,2,3,4 These observations have been confirmed and explained.5 If this ice really exists, it enables most exciting new class of inner Solar Systems human expeditions possible.6,7,8 To confirm the presence of ice, map its extent, and select human landing sites, a series of robotic precursor missions are suggested. At least two discovery-class missions already proposed would help verify Mercury polar ice.9 This paper suggests a modification of one such already proposed mission, as well as the requirements for a more sophisticated robotic lander class of missions and robotic sample-return class of missions. -------------------------------------------------------- Copyright © 1993 by Jonathan V. Post. Published by the American Institute of Aeronautics, Inc., and Space Studies Institute with permission * President and C.E.O. Mercury is a deadly world -- over 800 degrees Farenheit at the equator, during the closest approaches to the Sun every 88 days. This takes place at perihelion (36 million miles = 46 million kilometers) and doesnt last long, because of Mercurys swift orbital velocity (35 miles/sec = 56 kilometers/sec). But despite the broiling equator, it stays chilly at the poles. How cold?,As cold as 125 degrees Kelvin (minus 148 C., minus 235 degrees Farenheit) at the poles. How is this possible? Well, there are only three ways you can heat a body from outside: radiation. conduction, and convection. You can heat by radiation, as the Sun does to Mercurys equator -- but the solar rays strike slantingly and more weakly the closer we get to the poles. Brutal sunlight always smashes straight down on the equator, hot enough for metallic tin and lead to flow like water, over 800 degrees Farenheit during the closest approaches to the Sun every 88 days. By the same geometry, sunlight skims across frozen poles, blinding light with negligible heat. You can heat by conduction -- yet as fast as heat conducts to the poles from the core and the equator, it radiates away into the black sky. You can heat by convection, but there is virtually no air on Mercury to blow its sultry breath upon the poles. Mercury has an extremely thin atmosphere dominated by -- in order of abundance -- atomic Oxygen, atomic Sodium, Helium, atomic Potassium, and atomic Hydrogen; as we have known only since the 1985 work of A. Potter and T. Morgan.10 The pressure, measured in quadrillionths of Earths atmospheric pressure, is so low that you might more accurately think of individual air molecules travelling like bullets on parabolic paths. When they hit, they are almost immediately launched again by thermal energy. But when they hit at the cold poles, some of the molecules freeze fast to growing patches of ice. ...
Posted on: Sat, 22 Mar 2014 18:24:11 +0000
Trending Topics
Recently Viewed Topics
© 2015