studies and analyses. Among them were John O'Keefe of the Army Map Service, Luigi Jacchia of Harvard, Dirk Brouwer of Yale, and their colleagues. For the International Geophysical Year the Smithsonian Astrophysical Observatory had taken the lead in developing and putting into effect plans to use data from the IGY satellite camera network. As an outgrowth of an informal committee organized at the suggestion of R. K. C. Johns, the American Geophysical Union Committee on the Geodetic Applications of Artificial Satellites kept geodesists informed of the possibilities of the new tools. A committee report issued in September 1958 shows that considerable thought had been given to the subject.20

As early as 21 November 1957 the National Advisory Committee for Aeronautics had voted to establish a Special Committee on Space Technology.21 Chaired by H. Guyford Stever, dean of the Massachusetts Institute of Technology, the committee included several members from the Rocket and Satellite Research Panel, such as James A. Van Allen, its chairman; Wernher von Braun, leader of the German missile experts working

for the Army Ballistic Missile Agency in Huntsville, Alabama; and William Pickering, director of the Jet Propulsion Laboratory. The committee, assisted by a number of specialized subcommittees, formulated a space research program. Although the report, completed on 28 October 1958 after NASA was already operating, never was published, NACA people had had the benefit of the thinking of the committee and its various subgroups on a wide variety of subjects, including technology, space applications, the physical and life sciences, and manned spaceflight.22

With respect to manned spaceflight, both NACA and military agencies had been very active. NACA's prospective thinking in February of 1958 had envisioned the travel of man to the moon and nearby planets. During the summer of 1958 the Advanced Research Projects Agency was besieged with requests for support of Air Force and Army manned spaceflight proposals. But shortly after the passage of the NASA Act of 1958, President Eisenhower assigned the new agency the responsibility for manned spaceflight. In mid-September Administrator Glennan and Roy Johnson, head of the Advanced Research Projects Agency, agreed that the two agencies should work together on a man-in-space program, and to coordinate the activity they established a joint Manned Satellite Panel.23 Robert Gilruth, who was to be a key figure in the Mercury, Gemini, and Apollo programs, was chairman. By virtue of this spade work, NASA was ready only one week after its opening to proceed formally with Project Mercury, the nation's first manned spaceflight mission.24

The roots of the space science program went at least as deeply into the past as did those of the manned spaceflight program. Taking over the Vanguard program, assuming responsibility for much of the nation's sounding rocket research, and acquiring the Pioneer deep-space probes from the Air Force, NASA had an ongoing space science program from its first day. Building on these activities and drawing upon their own experiences of the past decade, the rocket research scientists who had come into NASA were able to put together a plan that described in a general way what NASA would be doing in space science for the next two decades. The shape of the emerging program was evident in NASA's first hearings before Congress.25

To trace the evolution of the space science program in the thinking of the NASA planners is interesting. A sheaf of working papers in the NASA files for January 1959 gives an overall summary of the space science program as envisioned at that time.26 The program was described in terms of the different scientific disciplines to which space research could contributefor example: particles and fields, astronomy, atmospheres, and ionospheres. A more formal document, 10 February 1959, elaborated further, listing atmospheres, ionospheres, energetic particles, electric and magnetic fields, and astronomy as areas of research within the NASA space science program.27 Within the larger categories was a detailed breakdown.

Atmospheric research had been a major part of the sounding rocket work of the past decade (chap. 6). It investigated the principal properties of the earth's atmosphere, such as the pressure, temperature, density, and composition of the atmosphere as a function of height and geographic location. Particularly important were the variations of these quantities with time, especially the variations caused by solar influences. With the prospect of sending spacecraft to other planets the comparative study of different planetary atmospheres would be immeasurably aided. Among the important solar influences to study were those causing atmospheric molecules to become ionized forming electrified regions known collectively as the ionosphere. Again, with the possibility of including other planets, the plural ionospheres was used. Energetic particles referred to planetary radiation belts, radiations in the interplanetary medium, and cosmic rays. Electric and magnetic fields in the upper atmosphere and space would be important aspects of relationships between the sun and the earth, and presumably other planets as well. There was considerable interest in studies of gravitational fields in connection with geodesy and the celestial mechanics of the solar system and particularly for investigation of various theories of relativity, for which it was agreed that satellites should be very effective. The areas of astronomy were the familiar ones of sun, moon, planets, and stars. With satellites measurements could be made in ultraviolet, x-ray, and other wavelengths that could not be observed at the ground.

Amplifying the general description of the program were several pages devoted to specific problems ripe for attack. For example, under atmospheres one asked what were the primary sources of energy affecting the high atmosphere, and what was the relationship of the Great Radiation Belt to the heating of the upper atmosphere. A question that was still not answered a decade later concerned the precise relations between the earth's surface meteorology and the upper atmosphere. Of particular importance was the problem of learning in detail exactly how the sun exerted its influence on the atmospheres of the earth and planets. For ionospheric studies it was regarded as important to obtain details on the structure of the highest regions. Of especial interest, one looked forward to the study of other planetary ionospheres. Typical among the problems under energetic particles and magnetic fields were those in pinning down exactly how solar particles behaved in the vicinity of planets and, in particular, how the aurora was generated. Under gravitational fields the first problem was to get a detailed analysis of the earth's field into its various components, since from this would flow the solution of many other problems. Likewise one looked forward to determining the gravity fields of other planets. In astronomy, the first problem was to learn the spectral emissions of the sun, stars, and interstellar medium. This selection of existing problems is only illustrative.

Even more detail could be found in a second document of February 1959 entitled "The United States National Space Sciences Program," which added biosciences to the list of space science areas.28 Of particular interest was the indication that working groups would be established immediately in half a dozen program areas, others later as needed. The evolution of the idea of working groups as a means of drawing outside scientists into the program will be discussed in some detail in chapter 9.

A five-page paper of 30 March 1959 elaborated on plans for a biosciences program, including the establishment of working groups in the area. By mid-April a paper titled "National Space Sciences Program," plainly a derivative from the 4 February document, showed clearly the directions the program was taking.29 Although this was only half a year after NASA began, the agency would follow those directions for the next decade.

This early thinking of NASA was reflected in the report the National Academy of Sciences made to the international Committee on Space Research at its second meeting held at The Hague, 12-14 March 1959. In this report the breakdown of NASA's February working papers was followed.30

Quite properly the planning began with a consideration of the scientific objectives to pursue, a listing of the important areas of research, and an assessment of the significant problems to attack. One can see this approach in the NASA documents of the first half of 1959. But a program-by which is meant a long term, continuing endeavor of rather broad general objectives-must be carried out in discrete steps. In NASA parlance such discrete steps were called projects. Thus, the astronomy program, which was to investigate the universe from above the atmosphere, might be expected to continue as long as space techniques could produce significant new information, and there was no foreseeable end to that. But a satellite project to measure gamma rays from the depths of the galaxy-which most certainly would further the astronomy program by shedding light on energetic processes in the galaxy-would be of limited duration, long enough to prepare, fly, and operate the satellite, and interpret the data obtained.

Even as NASA's program plans were being developed, the agency started numerous projects to conduct investigations ranging over the different areas of space science. In reporting on the program, then, it soon became possible to list ongoing projects in which the nation's scientists were participating. In April 1960 NASA's report on the space science program could go far beyond the generalities of the papers developed in early 1959.31 The various parts of the program were integrated under a few broad objectives; namely, to learn more about sun-earth relationships, the origin of the universe and the solar system, and the origin of life. The specific disciplines supporting the broad objectives were given as aeronomy, ionospheres, energetic particles, magnetic fields, astronomy, gravitational fields, lunar sciences, planetology and interplanetary sciences, and micro

meteorites and cosmic dust. The similarity to the earlier breakdown is evident, although a few new terms appear. Replacing atmospheres was aeronomy, a term coined by Sydney Chapman during the 1950s from the Greek words meaning "laws of the air." The term planetology had been introduced to mean the study of the body of a planet as distinguished from the investigation of its atmosphere and ionosphere. It was felt that dust in space might be an important factor in studying the origin and evolution of planetary systems and in designing spacecraft for interplanetary flight, hence the prominence given to it. Micrometeorites were simply cosmic dust particles that struck another body such as the earth or a spacecraft.

In the April 1960 paper a great deal of detail could be given on projects to support the various programs. Under each of the above disciplinary categories were listed physical parameters to be measured, instruments to be used, experimenters responsible, and sounding rockets, satellites, or space probes to be employed. For example, under aeronomy the 30-meter sphere of thin metallized plastic constructed by William O'Sullivan of Langley Research Center was listed as a sounding rocket experiment to measure upper-atmosphere densities. The sphere would be carried aloft, ejected at altitude, and inflated. Accurate measures of the air drag on the falling sphere would give the desired densities. O'Sullivan's sphere was the forerunner of the Echo passive-communications satellite launched on 1 August 1960, which observers around the world were able to follow with the naked eye.

Under energetic particles the document had a long list of experiments on radiation belts and the magnetosphere, some of them having already been carried out successfully. For the related area of magnetic fields, Pioneer 5 was shown as having been launched into deep space in March 1960. Radio, gamma-ray, solar, and stellar astronomy projects were in the works, and a solar observatory satellite was actually under development. A considerable amount of work was indicated as under way in gravitational fields, relativity, and geodesy. A series of lunar probes was also listed.

From this point on, the space science program evolved pretty much along the lines already established. A continuing effort to keep a spark of life in the planning recast the program objectives in different words from time to time. For example, in March 1961 the principal areas in the space science program were grouped under the headings: the earth as a planet, the earth's atmosphere, solar activity and its influence on the earth, origin and history of the moon and planets, and the nature of the stars and galaxies.32 By the mid-1960s, when NASA made a special effort in its authorization hearings to present the broad perspective of the space science program, the principal categories had been reduced to two: exploration of the solar system. and investigation of the universe. Elaborating on these objectives