Fred Hoyle - Element 79

The first landing didn’t do much more than that. Down onto the deck, a judicious peek outside, then quickly back to the lunar-orbit rendezvous. Although it had cost the best part of one hundred billion bucks, hardly anybody now doubted that it had been well worthwhile. There was the usual bitching, it was true, from the high-energy physicists, who were having difficulty in acquiring a single lone billion, but once high-energy physics moved under the control of NASA that particular moan soon died away. Getting all funds for science under a single agency began to seem more and more like a good idea. It kept things in perspective and in proportion. It was tidy. The N.S.F. was also moved over.

Since glamour was now off the gingerbread, the second lunar mission had perforce to make up in effectiveness what it lacked in sensationalism. It went to the Moon to work, to survey, to dig, and to probe. The crew on this occasion included both a scientist-astronaut and a scientist-passenger. Ironically enough, the second landing turned out far more sensationally than the first. The disaster was noticed by the men in the rendezvous vehicle. Everything was quite normal for the first two days, they said, then suddenly the landing station was gone. In its place a new crater had appeared about three hundred yards in diameter. The precise mechanism of the disaster was unclear at the time, for it must have happened while the rendezvous vehicle was orbiting on the far side of the Moon. Later research showed, however, that the second landing party had been the unfortunate victims of what came to be known as a “soda squirt.”

For a while there was discussion of cutting back the whole space program. But at length it was decided to press ahead with still greater vigor, in tribute to the space heroes, blown to perdition in some still-unexplained fashion.

Later missions very naturally proceeded with all due caution. It was discovered that ice lay below the dust and mud of the immediate surface of the Moon. There were huge glaciers shielded from space by the thin skin of dust. Wherever the skin was scraped away, the ice melted off into space very quickly. The temperature of the ice was found to increase with depth, which was natural, of course. This meant there must be liquid water low enough down. The water must be under pressure, a pressure generated by the weight of the overlying ice. Given any crack or hole in the solid glacier and, bingo, the water would stream explosively upward like an oil gusher. This was exactly what happened at places where the ice became exposed. More and more of the ice evaporated into space, until what remained became too thin to withstand the pressure of the liquid water below. So up came the water in a huge soda squirt. The water didn’t settle back, it simply fizzed off into space.

These events were watched by the later expeditions from a safe distance. The precaution was necessary, for the rush of the water was extremely violent. Usually it shot out at a speed of about one mile per second, over three thousand miles per hour, sufficient to blow a small crater. It was now easily understood how the hitherto mysterious chains of small craters had been formed; they were strung along the courses of underground rivers, they were the places where the water had managed to punch through to the surface. In the gaunt, gray world of the Moon, the emergence of billions of tons of water was a fantastic and wonderful event, not at all like a terrestrial geyser. It was the colors you were aware of, a blaze of color that filled the whole sky.

The next step was to use the Moon for developing the techniques needed in the conquest of Mars. A permanent lunar laboratory was established. The essence of the business was to achieve self-sufficiency with the aid of regenerative life-support systems. For energy in its grosser forms, an interesting multistage method was used. For a start, a compact nuclear reactor was transported from Earth. This was used to power small diameter boreholes through the ice. So long as the water was allowed up only in small quantities, through a carefully constructed pipe, the flow could be kept under control. The critical thing was pressure at the surface. Instead of the water being permitted to spurt out freely into a vacuum, the pressure was taken down in several stages, in each of which the speed of the water was adjusted to match a set of turbines. Getting everything right in the beginning was very tricky indeed. However, once the difficulties were past, abundant energy was available in practically a permanent supply. Technically it was hydroelectric power, but on the Moon the water flowed uphill, not downhill, as on the Earth.

Oxygen came in ample quantities from the dissociation of water. Ultraviolet light from the Sun produced the dissociation, yielding nearly a kilogram of oxygen per day per square meter of exposed area. Ten square meters gave sufficient oxygen for a man. Nitrogen and carbon were problems, particularly nitrogen. The water from below had a lot of carbon dioxide dissolved in it, however. Really, it was soda. Less nitrogen, but enough, also came up with the water. Photosynthesis was quick and efficient, enabling a subsistence diet to become established. Trace elements, vitamins, and so on, were still imported from Earth. Even this dependence could have been overcome in time, but the time available for research on the Moon was now running out. As a NASA spokesman succinctly put it, the nation had acquired a Martian-wise capability.

it had come as a shock many years earlier to discover how very similar the Martian surface is to the Moon. This should really have been obvious from the beginning. It should have been obvious that the general dappled appearance of Mars is the same phenomenon as the “Man in the Moon” pattern of the lunar surface. The pattern comes from an overlapping of circular patches, like the “seas” or maria of the Moon, themselves produced by the large-scale impacts of huge meteorites, craters on the biggest scale of all. The canals that many observers thought they had seen turned out to be mere chains of craters. The human eye always tends to connect together a number of dots along a line, to see them as a complete line. This became obvious from the first fly-by pictures. Mars was simply a larger-scale version of the Moon.

This was why the lunar laboratory was so important. Much the same conditions could be expected on Mars, the same glaciers, the same water problems. Apart from the sheer dynamics of reaching Mars, demanding much more powerful boosters, apart from the length of the voyage—several months instead of days—most local problems should be less difficult on Mars. There would be somewhat stronger gravity, which was an advantage. The Martian atmosphere would remove the solar X-rays against which all lunar scientist-explorers had to be endlessly shrouded. There was some oxygen in the Martian atmosphere. Compressors would therefore give an adequate oxygen supply. The Martian atmosphere would reduce electrostatic effects so that dust would not be quite such a bad problem. The Martian atmosphere seemed to be an advantage in every way.

Both the atmosphere and the white polar caps of Mars were well understood now. With water coming up occasionally from below, exactly as on the Moon, thin polar caps of hoarfrost were just what one would expect. Martian gravity is intermediate between Earth and Moon. Terrestrial gravity is strong enough for the Earth to have retained most of the water squeezed from its interior throughout the eons. At the opposite extreme, the very weak lunar gravity of the Moon permits it to retain no surface water. Mars lies between. Mars holds water, but not for long. There is always a little water on the surface, water recently come from below which has not yet had time enough to escape away into space. The oxygen comes, of course, from dissociation of the water by sunlight, and carbon dioxide and nitrogen also come up with the water. The clouds observed from time to time by early astronomers were simply occasional squirts, released by an impacting meteorite from without. Mars was more subject to bombardment than the Moon, being nearer the asteroidal belt. Protecting spacecraft from impact was a serious difficulty, one that it didn’t pay to think about too closely.