In AUTUMN 1955, while the Naval Research Laboratory and the Martin Company were starting work on specifications for the vehicle, the United States National Committee for the IGY had organized a Technical Panel on the Earth Satellite Program (TPESP) to watch over the purely scientific phases of the project, to select the experiments to install in the birds, and, subject to USNC and Executive Committee approval, to fix the policies and procedures in regard to financial commitments, institutional relationships, and educational releases to the public. In assessing the work of the National Committee, the technical panels, and the working group-under the National Academy of Sciences (NAS) -it is essential to realize that, with the exception of the seven to eight men who composed the USNC's secretariat and the handful of scientists whose government jobs extended to participation in IGY planning and action, all members gave their services without compensation. Academy funds, derived from the National Science Foundation, paid travel expenses and in some instances a modest per diem to cover living costs during protracted committee and panel sessions. But most of the men who spent days, sometimes weeks, in directing IGY programs volunteered their time, despite demanding professional obligations on university campuses or in industry. In the earth satellite project, moreover, panel and working group members also risked their future standing in the scientific world, for the success of the venture was far from assured and failure could end in the men responsible for the scientific aspects of the undertaking being labeled incompetent.

The Technical Panel on the Earth Satellite Program consisted of the chairman, Richard Porter, who was also a member of the Stewart Committee, Joseph E. Kaplan and Hugh Odishaw, USNC chairman and secretary respectively, Homer E. Newell, Jr., of NRL, William H. Pickering of the Jet Propulsion Laboratory at the California Institute of Technology, Athelstan Spilhaus of the University of Minnesota, Lyman Spitzer, Jr., of Princeton University, James A. Van Allen of the State University of Iowa, and Fred Whipple of the Smithsonian Astrophysical Laboratory. After Spitzer resigned in 1956, Gerald Clemence of the Naval Observatory and Michael Ference, Jr., of the Ford Motor Company brought the number to ten, and in the months after Sputnik the addition of Alan Shapley of the National Bureau of Standards and W. W. Kellogg of the RAND Corporation further enlarged the membership. By invitation, a few guests and observers always attended the meetings to contribute information or represent such agencies as the National Science Foundation, the DoD Comptroller's Office, and the office of the Assistant Secretary of Defense for Research and Development.¹

The most urgent task of the panel when it first met was' the drafting of a budget, since if the USNC was to get adequate supplemental funds in fiscal year 1956, the request had to reach the Science Foundation in the near future and go thence to the Bureau of the Budget and Congress. The panel's main quandary was what to expect from the Department of Defense in keeping with the Department's pledge "to furnish logistic support for the NAS-USNC Satellite Program within reasonable limits." What were reasonable limits? The commitment as it stood encompassed plans for "six earnest tries" at a satellite launching, but the Academy's goal was twelve, since scientists, doubtful of being able to locate in space and track every bird put into orbit, feared that fewer than twelve attempts would imperil acquisition of the scientific data at which the program was aimed. Irrespective of how many of the six shots authorized to date were successful, would the Defense Department share the cost of an extended program? The panel decided to divide its budget estimates into two phases, one covering from April 1956 through March 1958, during which time the six tries already approved would presumably be completed, and Phase II running for another one and a quarter years; assuming continued DoD participation, Phase II should permit another six launchings. The panel appointed a three-man working group to prepare this double set of estimates.²

When the working group tendered its suggested budget in November, the report set $8.337 million as the sum needed to cover National Academy expenses for instrumentation for the six operation vehicles, ground stations, and "certain scientific personnel" during Phase I; a "guesstimate" put Defense Department costs at about $19.1 million, Optimistically a staff member of the USNC secretariat explained that while "areas of overlap of responsibilities" between the Academy and the military would doubtless occur, "it is expected that mutual understanding will prevent difficulties." Inasmuch as the Defense Department had not yet agreed to support Phase II, figures for extension of the program through June 1959 were more tentative, but an additional $20 million appeared to be enough. Of that amount about $7.1 would be Defense money; IGY funds, if need be, could logically meet the $6 million cost of procuring six additional vehicles. All told, NAS-NSF expenditures for Phase II would come to approximately $10.87 million, a figure that would keep Academy expenditures for three and a quarter years well below the $20 million ceiling set by the National Committee for the satellite program. "With the understanding that some latitude would be given for minor adjustments," the panel approved the estimates.³ The tabulation of costs to he financed by the Science Foundation are shown in the table.⁴

In view of the stress the Stewart Committee's original report had laid upon the advantages of the Minitrack system, the nearly $3 million allotted in the IGY budget for optical tracking may seem surprising. Years later John Hagen remarked that, as things turned out, the program would have lost little from omitting provision for optical tracking. But in 1955, and indeed long afterward, most of the IGY committee and satellite panel believed tracking by cameras, telescopes, and theodolites vitally important. Not only would it be more accurate, but it might well be a more dependable, albeit a more restricted, method than a still untried electronic system. "One should act," ran the panel minutes, "as though there were only a 50-50 chance of the Minitrack's operating successfully (although actually the Minitrack engineers estimate that on any one firing the chance of successful operation should be better than 95%)." Athelstan Spilhaus furthermore contended that many people would have little faith in information relayed by telemetry, that form of occult magic; they would put stock in a man-made moon only if they could see it with the help of simple instruments as it passed overhead. Consequently plans for optical tracking received careful attention. To begin with, a Working Croup on Optical Observations and Tracking consisting of Fred Whipple and Lyman Spitzer presented a scheme of enlisting the help of professional astronomers, training teams of amateur observers, and setting up central administrative, computing, and analysis facilities. The panel promptly voted to ask the USNC to obtain from the Science Foundation a grant of $50,000 for the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, to oversee the establishment of twelve observation stations, arrange for procurement of special equipment, secure the collaboration of governmental and other professional scientific groups, and recruit amateurs for what later came to be called "Moonwatch." The plan of operation appeared in the diagrammatic form shown on page 101.⁵

Although formal action on the plan had to wait upon passage of a supplemental appropriation for the IGY, Whipple at once set about organizing SAO's optical tracking scheme.

The enthusiasm of amateur star-gazers over the opportunity to have a part in an important scientific venture early impressed the USNC's Executive Committee. Here evidently was a simple way of widening public interest in the IGY both at home and abroad. In response to the committee's suggestions that the men in charge of other phases of the IGY open the doors to amateur participation, in early 1956 the technical panel authorized "Moonbeam" for ham radio operators; the Naval Research Laboratory accepted responsibility for indoctrinating licensed applicants in the essential do's and don't's, chiefly by means of a descriptive and technical manual to be prepared by John Hagen. At the same time Whipple agreed to draft instructions for Moonwatch teams.⁶

When hearings on the IGY supplemental budget began on the Hill in March 1956, spokesmen for the Science Foundation and the National Academy had some difficulty in justifying the request for $19.262 million for the satellite program, by far the largest single item in the $28 million budget. Patiently they explained that the undertaking had assumed new dimensions since the White House announcement of July 1955, that more nations, notably the U.S.S.R., were now participating, and that American universities would bear much of the expense of interpreting the scientific data picked up from the satellites. Congressional questions hammered away at why the Academy planned to share its findings with other nations and yet was asking the United States government to spend millions of taxpayers' money to acquire the information. Would anything useful, congressmen asked, come out of the program? To a question posed by a senator, "How do you propose to get results from devices in the satellite?" Joseph Kaplan replied-

We literally talk to the satellite, using radio waves, which is a technique

known as telemetering…

In conventional rocket research, the techniques of recovering equipment by means of parachutes has been well worked out…But in the satellite nothing but the radio signals will be recovered at first.⁷

Richard Porter defended the request for money enough to expand the number of launchings from six to twelve: twelve, in the judgment of the Academy's technical panel, represented "a realistic program." Although Congress in the end pared $l million from the Foundation's IGY budget and NSF and the USNC then reduced the total for the satellite program to $18.364 million, the panel believed that it could still manage to finance the twelve shots. Kaplan's summary of events ran: "Berkner sold the program to the Academy; Waterman sold it to the White House; I sold it to Congress." He did not add that nobody sold it to Secretary of Defense Wilson or that Congress, though granting funds to the Science Foundation for it, never appropriated a cent to the Navy for the vehicle.⁸

Meanwhile the TPESP had set in motion a plan for obtaining proposals for scientific apparatus to put into the instrumented satellites, Recognizing that selection of the most rewarding experiments would be simplified by full discussion of possibilities among geophysicists, the TPESP decided to organize a symposium on "The Scientific Aspects of Earth Satellites." By briefing participants on the limitations which the vehicle would impose on satellite instrumentation, the panel should avoid exposure to a flood of impractical ideas and find the choice among useful proposals easier. The originators of the approved experiments would then receive grants from the Science Foundation to assist them in developing the implementing instruments. Publication of abstracts of the papers presented, furthermore, would serve the purpose of informing foreign scientists about the scope of the American program. Van Allen and Odishaw to whom the panel entrusted the task of arranging the symposium concluded that the tenth anniversary meeting of the Upper Atmosphere Rocket Research Panel scheduled for late January 1956 would be the most suitable occasion, for it would bring together men already familiar with high atmospheric research.

Van Allen's letter to members of the rocket group explained that the symposium was to be kept to not more than fifty persons, a number that would embrace most American scientists qualified by training and experience to contribute to a meaningful discussion in this little known field. The papers to be read should be "specific, critically considered, and pertinent to the present state of technology and the reasonable projection of this technology into the next few years." Plans for physical experiments and observations, theoretical and interpretative matters, and techniques and components of a novel nature would all be acceptable topics, but not space medicine, or the legal and political aspects of the satellite program, or essays dealing with vehicle propulsion and guidance.⁹

Although the scientists who presented papers two months later at the Ann Arbor symposium generally adhered to the rules Van Allen had laid down, the problem of appraising the relative value of their propositions led the panel to ask Van Allen to head a Working Group on Internal Instrumentation to screen out the best ideas for later panel consideration, unobtrusively to elicit proposals in neglected fields, and to recommend priorities for "on-board" experiments to be flown in the first satellites.¹⁰ To help the panel reach decisions on other complicated technical problems, in March the TPESP created also a Working Group on Tracking and Computation chaired by Pickering. Inasmuch as the panel had to review working group recommendations carefully and, where they involved IGY finances and international relationships, had to submit them to the USNC and its Executive Committee for final endorsement, the arrangement meant a good deal of thrashing over the same ground. But no other method of handling IGY business was feasible. Academic scientists, upon whose knowledge the usefulness of the IGY depended, had to parcel out their IGY chores among each other and rely upon reports to keep themselves abreast of what their fellows were doing. That the system worked at all was due chiefly to Richard Porter's contributions of time and thought and to the efficiency of Hugh Odishaw and his assistants on the USNC secretariat.

During the spring of 1956 the panel discussed a variety of questions: how, for example, to evaluate the chances of a successful Russian satellite launching before the year was over, how to explain to the public the goals of the American program effectively, and how to obtain from the Naval Research Laboratory greater flexibility in satellite design and the telemetry and tracking systems to be employed. Discreet inquiries through the ruling international body for the IGY, CSAGI, appeared to be the best way to verify or put to rest the vague rumors of an early Russian satellite launching. Speakers at international scientific gatherings scheduled for the summer and autumn and at meetings of American societies should be able to disseminate accurate information about the Vanguard project. Publication in May of the abstracts of the papers read at Ann Arbor offered an impressive summary of what the program might accomplish. NRL, however, stood by its contention that all experiments installed in the birds should rely on the Minitrack and the types of telemetry NRL had already chosen. As for the satellite, Homer Newell reported that the Laboratory was going to produce at first some 6.4-inch as well as 20-inch spheres and thereafter would try other configurations, including perhaps the cylinder-shape that Van Allen advocated. Heavy instrumentation to check the performance of each stage of the launcher had to go into the test vehicles, but the Vanguard staff concluded that every test vehicle containing three live stages could carry also a small, lightweight satellite. If the 6.4-inch, 4-pound bird got into orbit, that success would not only testify to the adequacy of the launcher but permit later flights, unburdened with the test instrumentation, to carry the bigger spheres and more scientific paraphernalia." All these problems, however, faded into the background when the panel discovered that a budgetary crisis was putting the entire satellite program in jeopardy.

Paul A. Smith of the Department of the Navy had warned the satellite panel in March that then estimates pointed to a possible $20 million deficit in DoD funding for Vanguard. But panel members had not been seriously alarmed. Academy scientists, the Vanguard comptroller at NRL ruefully observed, looked upon the DoD as a "fat cat" that could afford anything it wanted. Surely the Department would find some way of honoring its commitments even though they were greater than originally expected. And, with over $18 million appropriated to the Academy for the satellite program, the USNC could pay for the second six vehicles and thus carry out Phase II. In April 1956 Newell and Ross Peavy of the USNC secretariat figured that the distribution of expenditures between the Academy and the Defense Department would be approximately as follows:¹²

A blow awaited the scientists when they met in June. A statement from the Pentagon informed them that since the preceding October the estimated costs to the military of providing six launching vehicles, building tracking stations and furnishing logistic support had nearly trebled and now ran to some $63 million. Only $21 million had been authorized. Secretary of Defense Wilson had consequently outlined to President Eisenhower four possible courses of action: (l) proceeding with the full NAS proposal of six pilot launchers and then six more; (2) proceeding with the six launchings already approved; (3) proceeding to the extent of available funds; or (4) canceling the program. Upon the advice of the Defense Department and the National Security Council, the President had chosen course 2 and was requesting the Bureau of the Budget to find additional funds for it. Worse followed: the emergency fund on which the Naval Research Laboratory had been drawing to pay contractors' fees was virtually exhausted, and the Defense Department, knowing that the congressional appropriation for the IGY included $10.728 million for a second six satellite launchings, now asked the Science Foundation and the Academy to turn over to the Navy $6 million immediately to prevent work stoppages on the test vehicles.

Feeling that the pistol had been put to its head, the TPESP reluctantly admitted that it had little choice. It would have to acquiesce in the transfer of the $5.8 million that would he surplus in the IGY budget if only six firings were to occur. The President had decreed only six earnest tries. But panel members insisted that a letter to the Science Foundation make clear that they would accept the reduction in the program and the sacrifice of IGY money only under duress and not by free will. They would continue to seek means of restoring the number of launchings to twelve, since half that number would probably mean at best getting not more than two satellites into orbit. They drew some consolation from a message from Alan Waterman "describing his understanding that `the need for and feasibility of constructing and launching six additional satellites will be a subject of review on the part of DoD.'" With that bit of reassurance in mind, the scientists stipulated that release of their surplus funds to the Defense Department "should not preclude the ultimate availability of equivalent funds if the expanded program should be deemed again feasible." The USNC and the Executive Committee agreed to the transfer of $5.8 million a week later.¹³

The indignation of the IGY group subsided somewhat during the summer. That the threatened work stoppage on Vanguard did not occur lightened the earlier tensions considerably. Over dinner at the Cosmos Club in mid-July Porter, Waterman, Admiral Rawson Bennett, Director of ONR, and Clifford Furnas, who had succeeded Quarles as assistant Secretary of Defense for Research and Development, had "a very useful and constructive discussion," as Porter described it. Over the division of responsibilities between the Academy and the military services, a differentiation supposedly clearly defined in 1955, confusion had risen in the intervening months. The four distinguished men, each speaking for his own organization, reached a general understanding that, in Porter's view, ironed out many difficulties. In a letter to Kaplan, Porter summarized the results:

l. The Earth-satellite program should be thought of as an IGY project in which the Department of Defense is cooperating, rather than as a D.O.D. project.

2. The D.O.D. has accepted the responsibility for development, procurement, and launching of the vehicles, and for demonstrating that the vehicles have or have not successfully been placed in orbit, and for providing certain other technical and logistic support.

3. The National Academy of Sciences retains the over-all responsibility for all phases of the scientific utilization of the satellite vehicles including precise determination of orbit and other measurements which may be made on…the vehicles for scientific purposes. Funds for this work have been appropriated by the Congress to the National Science Foundation, and the Foundation must properly account for these funds.

Later paragraphs underscored the Academy's delegation of authority to NRL to develop, procure, and operate high-precision radio tracking and telemetry stations, perform the analysis and computations of data, and devise and construct "certain instrumented experiments" to be carried on board the satellite. For those phases of the program, Porter's interpretation thus made the Laboratory an agent of the Academy. The Laboratory was to report its fiscal estimates and commitments in these areas regularly to the Academy and the Foundation. Publicity releases must obtain security clearance from the DoD and "policy" clearance from the IGY committee after consultation with the State Department. The USNC and the Defense Department would issue an official "Policies and Responsibilities document" as soon as both bodies had agreed upon the exact wording.¹⁴

The TPESP rested easier upon learning that Furnas, Bennett, and Waterman recognized the satellite program as an Academy project, in no sense a military venture. To the USNC, with its responsibilities to the international scientific community, it was important to have all doubts on that score removed. The verbal agreement, committed to paper only in Porter's personal letter to the USNC chairman, could not, however, change the sober realities of the situation. The major tasks of the satellite undertaking still fell to NRL, to the men who had originated the Vanguard design and its tracking and telemetry systems, and to those responsible for getting the satellite into orbit. The Vanguard team at the Laboratory had too much respect for the stature of the scientists on the IGY panel to dismiss their ideas lightly, but the men sweating over the job of producing a reliable launcher and dependable tracking and radio communication did not welcome gratuitous advice on how to do it.¹⁵ Although labeled an Academy program, in actuality its execution was divided into two unequal parts, the most costly and technically difficult of which was under Defense Department aegis. It was the problems arising out of this division of responsibility that later brought the National Aeronautics and Space Administration into the picture.

If few people as yet fully perceived the handicaps of split control, in December 1956-when, at the USNC's request, an ad hoc group consisting of Porter, Van Allen, Lyman Spitzer, William W. Kellogg of RAND, Newell, and Milton Rosen of NRL drafted a statement of the fields of research that a long-term, post-IGY satellite program should encompass-the group volunteered its comments on organization:

for an extended scientific program of national scope,… it is important that clear civilian authority (as by the National Science Foundation) be established for the planning and execution…In particular, it seems important to establish at the very beginning…a single comprehensive budget which will include all expenditures in connection with the program, including those to be made by organizations within the military establishments.¹⁶ Italics added.]

Before the autumn of 1958, the Department of Defense was accountable for expenditures for the satellite vehicles and radio tracking, the Science Foundation for the rest. Theoretically everyone understood these compelling facts. The TPESP, without relinquishing its plans for twelve launchings, had to acquiesce not only in the transfer of $5.8 million to the Navy in summer 1956 but also in the release of another $5.5 million of IGY money in October. The result was to perpetuate strains in the relations between the Science Foundation and the Academy and to encourage the panel to watch the Laboratory's performance with an increasingly critical eye. Homer Newell fortunately was usually able to explain to his panel members why engineering considerations obliged NRL to adopt features for the satellite that were unwelcome to the scientists and why delays occurred in the test program. Yet at times administrators of the Science Foundation felt impelled to intervene to keep relations between the Academy and the DoD on an even keel. Waterman, who had served as chief scientist at the Office of Naval Research before he became director of the Foundation, was a close friend of Admiral Bennett and at the same time understood the point of view of the gifted men attached to the Academy. Quiet and unassuming himself, he was an indispensable go-between in what was often a trying situation. His role was made harder, however, by the fact that most members of the TPESP and its working groups could allot only part of their time to the satellite program. They were only intermittently in Washington, and correspondence was a poor substitute for direct contact with day-to-day developments.¹⁷ Anxiety over progress on the launch vehicle crept into panel discussions increasingly often.

Relatively little controversy arose over NRL's plans for tracking, orbital computations, and data reduction. While the panel inclined to think Army estimates for constructing and operating the Minitrack stations excessively high, the TPESP swallowed its protests, inasmuch as Defense money was to pay the costs. The Working Group on Tracking and Computation, which scrutinized every feature of NRL's Minitrack and projected computing system, questioned every detail but generally endorsed the Laboratory's arrangements. A NRL contract with International Business Machines was especially satisfactory, partly because of the free services the company offered the government. Despite this generous arrangement, the prospective costs of data reduction were beginning to rise alarmingly." A contract with Radiation, Inc., of Melbourne, Florida, fixed a price of $458,000 solely for equipment and services for data reduction in connection with the telemetry to be used in launching the vehicle.

By comparison, the Smithsonian's optical tracking scheme looked cheap and easy, although scientists eager to obtain continuously recorded and telemetered data from instrumented satellites may well have regarded it as an extravagance at any price. The establishment and operation of twelve observing stations would cost nearly $2.371 million, but other expenses would be fairly light. IBM had offered free access to the 704 computer at the Massachusetts Institute of Technology for an hour a day through June 1959 and supporting services elsewhere for orbit calculations. The Army Signal Corps was willing to release a number of elbow telescopes for amateur use at military installations and the Air Force Aeronautical Chart and Information Center was ready to supply without charge some manpower and equipment for optical observation stations on islands in the Pacific. The panel, however, felt obliged to stipulate that all operators at these stations must be civilians to quiet fears of other nations that the United States was using the IGY for military ends. Yet the proffer of free services notwithstanding, as matters stood in the fall of 1956, panel chairman Porter envisaged a deficit of $1 million for the scientific phases of the satellite program.¹⁹

International cooperation was a basic element in the conception of the IGY, but whether other countries could or would contribute much to the American satellite undertaking long looked doubtful, Although scientists attending a western hemisphere regional conference of CSAGI in Rio de Janiero in July 1956 listened attentively to lectures given by John Hagen and William Pickering on the technical aspects of the American project, Gilman Reid of the USNC's secretariat reported: "Apparently very little information on the satellite had reached the South Americans and they regarded the program as exclusively a United States effort. In the Working Group Session…there was small attendance and an apparent lack of interest on how there might be participation in the program." This apathy was disconcerting, since several tracking stations along the north. south "fence" were to be located in South America. The International Committee, CSAGI, promptly urged that every National Committee appoint a "satellite reporter" to facilitate the channeling of information.²⁰ Lloyd Berkner, American representative on CSAGI, already was functioning in that capacity for the United States. CSAGI made further constructive recommendations at the meetings in Barcelona in September: every National Committee should report on its capacity to set up amateur observation stations, and standardization should everywhere obtain in radio tracking and telemetry systems so as to correspond to those announced by the United States. Members of the American delegation pushed the theme of collaboration with "strong invitations" to other countries to participate; the United States National Committee would issue a technical manual to assist them.

At this point the Soviet National Committee formally announced to the international gathering that the U.S.S.R. also had inaugurated a satellite program, "by means of which measurements of atmospheric pressure and temperature, as well as observations of cosmic rays, micrometeorites, the geomagnetic field, and solar radiation will be conducted. The preparations for launching the satellite are presently being made." Although by no means certain about how much technical information the Soviets would release, Americans were relieved to have Soviet intentions brought into the open. Hugh Odishaw suggested to the panel that autumn that here might be the means of inducing the White House to restore the Academy's twelve-vehicle program. An inquiry sent a month later from the USNC to the Russians asked advice on where the United States should set up observation stations to track future U.S.S.R. satellites. As half expected, no explicit answer was forthcoming.²¹

Publicizing of satellite plans at the CSAGI sessions nevertheless benefited the American program. Australian scientists opened negotiations for a Minitrack station at Woomera which they would maintain and operate. England, France, and Italy expressed readiness to contribute various services. And the World Meteorological Organization was considering offering its network for the transmission of data.²² Whipple reported that prospects were good for recruiting Moonwatch teams in Australia, Japan, South Africa, and possibly India, and that, provided the United States supplied the cameras, Australia, Spain, Ethiopia, Iran, and Japan wanted to establish optical tracking units. All told, by late autumn 1956, months before Lloyd Berkner and members of the secretariat completed the 415-page handbook entitled Rockets and Satellites the response of the international scientific community was gratifying. It would not pay the bills, but it should inspire the White House and the American Congress to support the venture on a generous scale.

In any case the Academy must keep other nations informed about American plans and progress. The satellite manual went out in draft form to all national committees in August 1957, an amended version in November after the first Sputnik flight. Every National Committee, the TPESP agreed, should receive advance notice of launching schedules, the predicted orbit of each bird, what telemetry signals to watch for in tracking, the nature of each onboard experiment, and the method of coding data, Within five months of a successful launching, standard astronomy periodicals with an international circulation should carry detailed reports on orbital observations, and the results of scientific experiments should be released within eight months "in reduced, corrected and calibrated form," together with pertinent interpretations.

The panel's chief worry as 1957 approached was the steadily rising cost of every phase of the scientific program, particularly the Baker-Nunn tracking cameras, orbital computation and data analysis, and the sums needed to supplement the grants to scientists preparing apparatus for onboard experiments. Porter and Van Allen argued that if expenses must be cut sharply, it would he better to drop one or more tracking stations rather than to reduce the funds for experiments. Meanwhile the TPESP must make a final decision about which experiments were to be flown in the first satellites.²³ Postponed until Van Allen and his Working Group on Internal Instrumentation had analyzed the pros and cons of every proposal, the selection could not be put off further.