om Earth's gravity.

Another possibility, of course, is atomic energy about which much has
been said and written. If, as some scientists believe, extensive space
exploration by manned crews will depend on harnessing this great source
of energy--both for booster purposes and for operating spacecraft in the
distant parts of our interplanetary system--this fact alone may assure
that the obstacles to practical nuclear energy are overcome faster and
more completely than would otherwise be the case. It is interesting to
note that the science of controlling nuclear fusion (as opposed to
fission) has come so far in the past several years that 11 private power
companies are pooling their resources to advance this state of the
art.[37]

_New water sources and uses_

A look into the future indicates very strongly that water will become a
major world problem, possibly by the beginning of the 1970's, which is
likely to be another "dry" decade. Present water supplies, coupled with
the increasing population and the many new uses for water, are barely
adequate now. In another 10 years the situation could be critical.

Part of our national space program includes studies on how to use and
reuse water to the best advantage of the human in space. A number of
avenues are being followed, including vaporization of volatiles in
biological wastes.[38]

From research of this kind it is more than possible that knowledge will
evolve which will prove useful in the practical production of fresh
water from other chemical compounds or mixtures, including seawater.
More than that, it could lead to new ways for extracting much needed
materials from the sea. Seawater contains 40 basic elements, 19 in
relatively copious amounts. These elements run from 18,980 parts parts
per million of chlorine to 0,0000002 part per billion of radium. Yet, so
far, we have learned to extract only bromine and magnesium in useful
amounts.[39] Conversely, the study of how marine animals extract rare
elements from the seawater, such as the extraction of copper compounds
by the octopus, could provide astronautic researchers with important
clues for keeping man alive in space.

_Noise and human engineering_

This is a field in which research has been going on seriously for only a
few years. Most of it has developed since World War II. Human
engineering is involved primarily with the reaction of people to their
immediate surroundings and how to arrange those surroundi