Orbital Sensing Instruments
Eight types of instrument are under consideration for the remote-sensing activity. Spectrometers measuring gamma rays, x-rays and alpha particles emerging from the lunar surface would be able to detect several elements. The gamma-ray instrument could ascertain the amounts of iron, potassium, thorium and uranium in the top foot of the lunar surface. The x-ray instrument would receive radiation excited by the sun in a very thin surface layer and give information on the concentration of major elements such as silicon, magnesium and aluminum. The alpha instrument would reveal if there were any extensive leakage of radon gas from the lunar interior, such as often accompanies volcanic or hot-spring activity on the earth. An infrared radiometer would measure infrared emission from the surface and thus would be able to find hot spots and volcanic activity. A gas mass spectrometer would measure the number and type of atoms around the service module, thereby determining the density and composition of the vanishingly small amounts of gas at lunar orbital altitudes. An electromagnetic sounder would bounce pulses of radio waves (10 kilohertz to 100 megahertz) off the moon and measure how much came back, thereby finding out about subsurface layering and determining whether there is chemical differentiation or even possibly a layer of ice. A metric camera would photograph most of the moon with good geometric control in order to determine how out-of-round the moon is and whether the centers of maria are lower than the edges. A laser altimeter would bounce a light beam off the lunar surface to measure altitude accurately; such measurements, taken together with orbital data and information from the metric camera, would help to determine the moon's shape.
This kind of broad coverage would mesh well with the detailed coverage astronauts on the surface would make of small areas. Each landing would provide a standard for the orbital experiments by measuring in detail what the instruments should see from orbit. The orbiting instruments then would yield a far broader coverage of surface characteristics than could be obtained from manned landings alone.
Attainment of the goals we have described will still leave several exciting frontiers for lunar exploration. They include visits to Mare Orientale, the polar region and the far side of the moon. Such visits will require the development of a new technology.
Long-Term Goals
Mare Orientale, the huge "bull's-eye" feature discovered in Lunar Orbiter photographs, is on the far western edge of the moon as viewed from the earth. It is a splendidly preserved, concentrically layered feature probably formed by the impact of a giant meteorite. The feature offers an unparalleled challenge for exploration, but it also presents large operational difficulties for a landing. The Cordillera Mountains, which ring the Orientale basin to form a circular outer scarp some 960 kilometers in diameter, are among the most massive on the moon, rising some 18,000 feet above the adjacent terrain. Perhaps this site, of all the possible ones on the moon, offers the best opportunity for studying the evolution and history of the moon.
A polar landing is a particularly fascinating prospect. Areas near the poles are in permanent shade, so that one might hope to find frozen ammonia, carbon dioxide, water and similar volatiles that otherwise would have escaped from the moon long ago.
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5 Comments
Add CommentThe Apollo missions were truly 50 years ahead of their time. 50 years societally & technologically. We ought still to look back at what our ancestors achieved, with the resources at hand, and the will in mind, in awe.
Reply | Report Abuse | Link to thisI disagree hotblack, the Apollo missions were 7-10 behind the times. If Wernher von Braun was given the opportunity earlier, we would have gotten to the moon by 1959-62. The German scientist was way beyond his time. In one word "Brilliant". Why doesn't Nasa have any of these guys around?
Reply | Report Abuse | Link to thisPerhaps technology. But Werner Von Braun as a Nazi was societally 1000s of years behind. Better to not have achieved the moon landing and other technological goals than be a Nazi
Reply | Report Abuse | Link to thisdoron, surely you must be aware that Von Braun was a reluctant Nazi. He earned the enmity of his superiors on several occasions because of his outspoken vision of rocket-enabled space travel and exploration, rather than rocket-enabled world domination. Von Braun was not enthusiastic about the Nazis or the war. This characteristic almost cost him his life. Viewing the past through the lense of the present affords many opportunities to wax morally superior to one's ancestors. The moon landings were a culmination of Von Braun's inspired vision of human progress, and had nothing to do with the Nazi Party. Perhaps you had better get your own house in order, doron - before you ask the entire human race to discard any dreams of reaching beyond, for fear of disturbing a tree or a slumbering faun.
Reply | Report Abuse | Link to thishotblack - Do you know how much I despise those who state that "so-and-so was ahead of their time" simply because the ball got dropped later on? Apollo was firmly of its time. The moon mission could have been completed earlier than 1969 had it not been for delays. Saying that Apollo was 50 years ahead of its time is the same as saying its OK that we're currently doing nothing of consequence in space. I vehemently disagree with this state of affairs. I will add, hotblack, that using your logic, Apollo wasn't just 50 years ahead of its time. If the Chinese make it to the moon by 2020, Apollo will be officially 61 years ahead of its time. If you ignore the Chinese and just count NASA, well... you might have to wait a pretty long time to find out. They'll probably not go their again. We entered our long decline a while back.
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