Exploring the Unknown - NASA's History Office

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OBSERVING THE EARTH FROM SPACE
uncertain terms proposals that meteorological satellites be commercialized. The debate
about turning Earth resource satellites over to private industry has been long and controversial,
and by the time privatization occurred, the U.S. system had fallen behind the state
of the art in important aspects. This debate also contributed to the slow development of
commercial remote-sensing satellite systems. (The “value-added” business for data from
meteorological and land remote-sensing satellites has been more commercially successful.)
Meteorological Satellites
Today’s widespread familiarity with satellite images used by television weather forecasters
encourages the assumption that meteorological satellites were an eagerly awaited
breakthrough in the technology underpinning weather forecasts. In fact, at the start of the
space age, meteorologists were not certain satellite data would prove useful. One of the
pioneers of meteorological satellites, Harry Wexler, wrote in 1954:
To predict the future of the atmosphere, the meteorologist must know its present state—as
defined by the three-dimensional distribution of pressure, temperature, wind, humidity. . . .
Knowing the present state of the atmosphere and past motions of the storms enables a prediction
to be made by extrapolation and other techniques. 3
Wexler pointed out that a satellite could provide only a “bird’s eye” view, not the threedimensional
data meteorologists needed. Therefore, a satellite would “serve principally as
a ‘storm patrol.’” 4 [II-1] A warning of a severe storm obviously would be of great practical
value, but most of the practice of meteorology addressed more routine situations. A meteorologist’s
desire for three-dimensional measurements of many variables was one of the
arguments for developing more sophisticated weather satellites in the 1960s and 1970s.
Because the value of gathering weather data from satellites was not immediately obvious
to civilian meteorologists, early meteorological satellite proposals emphasized military
uses. Ground stations and hurricane patrol airplanes provided acceptable storm warnings
for the continental United States and nearby waters, but the Navy needed storm warnings
in whatever remote areas ships might be operating, and the Air Force had similar needs
for worldwide forecasts.
Planning for a U.S. space program began with a 1946 Project RAND report titled
“Preliminary Design of an Experimental World-Circling Spaceship.” 5 This report emphasized
various military applications of a satellite; it noted that “perhaps the two most important
classes of observation which can be made from such a satellite are the spotting of the
points of impacts of bombs launched by us, and the observation of weather conditions
over enemy territory.” 6 In the section of the report discussing the scientific uses of a satellite,
the authors commented that observations of cloud patterns “should be of extreme
value in connection with short-range weather forecasting, and tabulation of such data over
a period of time might prove extremely valuable to long-range weather forecasting.” 7
Later RAND studies sought to tackle the problem of whether cloud images alone
3. Dr. Harry Wexler, “Observing the Weather from a Satellite Vehicle,” Journal of the British Interplanetary
Society 7 (September 1954) 269–76; see Document II-1.
4. Ibid.
5. For the history of Rand’s role in early space planning, see Merton E. Davies and William R. Harris,
RAND’s Role in the Evolution of Balloon and Satellite Observation Systems and Related U.S. Space Technology (Santa
Monica, CA: The RAND Corporation, 1988).
6. Douglas Aircraft Company, Inc., “Preliminary Design of an Experimental World-Circling
Spaceship,” Report No. SM-11827, May 2, 1946, p. 11, Space Policy Institute Documentary History Collection,
Washington, DC.
7. Ibid., p. 13.