During the 1940's and 50's rockets were achieving higher and higher attitudes with each test. Thus, the question was raised, where does outer space begin? Answering this question depends upon with whom you are discussing the subject. A doctor would state that outer space begins when the human body can no longer survive in the atmosphere. A propulsion engineer might say that space begins when a jet engine which needs air from the atmosphere to function can no longer operate. An aerodynamic engineer might say that space begins when there is not enough of an atmosphere for an aircraft's control surfaces to operate the craft. A bureaucratic agency might have one definition and an international organization may have another.
Obviously space does not start at the surface of the Earth because that is where our atmosphere pragmatically begins. If we climb to about 3000 meters (m) (10000 feet) we find that the amount of oxygen present and the pressure with which this oxygen enters our bodies is really not enough to keep a human body operating efficiently, although numerous people have adapted to live and work at this level (e.g. LaPaz, Bolivia; Quito, Equador; Katmandu, Nepal). The Federal Aviation Administration has dictated a regulation that whenever pilots fly above 3000 m (10000 feet) they will have supplemental oxygen available for them and their passengers. The United States Air Force goes a little further and states that their pilots will be on oxygen above 10,000 feet cabin pressure altitude. As altitude increases, the need for supplemental oxygen also increases.
At 5309 m (18000 feet) one half of the mass of the atmosphere is below this attitude. At this point a pilot who is at this cabin altitude must be on oxygen or a condition known as hypoxia (lack of oxygen to the blood or circulatory system) will render the aviator unconscious within 30 minutes.
At 16,000 m (16 km or nine miles) the use of supplemental oxygen fails as a sustainer for human life. At this altitude the combined pressure of carbon dioxide and water vapor in the lungs equals the outside atmospheric pressure and supplemental oxygen alone cannot reach the blood without additional pressure. Therefore, an individual must be in a pressurized cabin or wearing a pressure suit.
At 20 km (12 miles) the outside atmospheric pressure equals the vapor pressure of the human body or about 47 millimeters of mercury. In this environment bubbles of water and other gases begin to form in the body. The bodily fluids begin to literally boil. A pressurized cabin or a pressure suit is a requirement to protect an individual at this altitude from this violent condition.
At 24 km (15 miles) an aircraft's pressurization system no longer functions economically. There is so little oxygen and nitrogen at this altitude that it cannot be compressed to protect the pilot, crew, or passengers from the outside elements. Also at this altitude, the ozone layer begins to form in the atmosphere. Even though ozone consists of three atoms of oxygen per molecule, this substance is poisonous to the human body and compressing ozone would poison the cabin and its occupants. At this altitude the cabin or space suit must have its own pressure and oxygen independent of the outside atmosphere. For the human body space begins at this point because above this altitude a human must carry everything in order for the body to survive. This is probably the medical definition of where space begins.
At 32 km (20 miles) turbojets can no longer function. Used today as a means of propulsion for all modern jet aircraft, turbojets intake air and compress it by means of fans to mix with fuel for combustion. At 32 km there is not enough air to compress for mixing with the fuel; above this altitude aircraft must use ramjets. A ramjet operates similar to a turbojet except that a ram jet compresses air using supersonic shockwaves rather than fans. The speed of the air going through the shockwave compresses it much more efficiently than the mechanical turbojet.
At 45 km (28 miles) there is not enough air even for a ramjet to operate. Above this altitude a propulsion system needs to provide its own oxygen, also known as oxidizer, as well as fuel, i.e. a rocket. To a propulsion engineer space begins above this altitude.
At 81 km (50 miles) one government agency, the United States Department of Defense says that space begins because it awards all pilots who fly above this altitude astronaut wings. This group not only includes all the people who have flown the space shuttle and various other craft into space, but also the X-15 pilots who flew above this altitude.
At 100 km (62 miles) aerodynamic forces are no longer effective enough to move the various control surfaces to control an aircraft. The rudder, the aileron, and the elevator are no longer effective because there is not enough atmosphere for either lift or drag the two major aerodynamic forces to be effective. At this altitude the sky is dark; the stars no longer shimmer, but are hard points of light. Other than on-board equipment, there is no sound; no sonic booms, no explosions, or no shockwaves can be heard in space.
International law states that there is no definitive point where the atmosphere ends and space begins. The major space powers accept the following definition: Space begins at " the lowest perigee attained by orbiting space vehicles...", although this will vary with the size and shape of the vehicle. Perigee is the closest approach point to the Earth in an elliptical orbit. A potential challenge to this definition occurred in 1976 when eight equatorial nations issued declarations of sovereignty over the geosynchronous orbit belt which lies 35862 kilometers above the equator. Columbia, Equador, Brazil, People's Republic of the Congo, Zaire, Kenya, Uganda, and Indonesia also stated that they would defend such areas. But in 1980 the United Nations determined that such claims were null and void because Outer Space is international territory.
As the result of a large, dedicated effort by scientific-research institutes and construction bureaus, the world's first artificial satellite of the Earth "Sputnik" (the Russians' word for "traveling companion") was been created on 4 October, 1957. Poems lyricized the event, like "Leap into the Future" and "Scouting the Celestial Deep." An ephemeris, showing the times when the carrier rocket would be visible over cities in the USSR, as well as Detroit and Washington, was printed like a train timetable.
With the development of large Soviet ICBM's, it quickly became obvious that a missile that could lift a 5 ton nuclear warhead across an ocean on a ballistic orbit could lift a small payload into a stable, low-Earth orbit. Work began in early 1956 on object D (or D-1) was so named since it would be the fifth type of payload to be carried on an R-7 rocket. Objects A, B, V, and G were designations for different nuclear warhead containers. The satellite was a complex scientific laboratory, far more sophisticated than any other science proposal from the period. While Soviet engineers depended a great deal on Tikhonravov's early work on satellites, much of the actual design was a journey into uncharted territory. There was little precedent for creating pressurized containers and instrumentation for work in Earth orbit, while long-range communications systems had to be designed without the benefit of prior experience. The engineers were aware of the trajectory tracking and support capabilities for the R-7 missile, and this provided a context for determining the levels of contact with the vehicle. The fact that the object would be out of contact with the ground for long periods of time (unlike sounding rockets) meant that new self-switching automated systems would have to be used. The selection of metals to construct the satellite also presented problems to the engineers, since the effects of continuous exposure to the space environment was still in the realm of conjecture. The experiments and experience from sounding rocket tests provided a database for the final selection.
Technical work on the vehicle officially began on 25 February 1956 with actual construction beginning on 5 March. By 14 June, engineers finalized the necessary changes to the basic version of the R-7 ICBM in order to use it for a satellite launch. The new booster would incorporate a number of major changes including the use of uprated main engines, deletion of the central radio package on the booster, and a new payload fairing replacing the old one used for a nuclear warhead.
By 25 January 1957, the Chief Designer approved the initial design details of the satellite, now officially designated Simple Satellite No. 1 (PS-1). On 15 February, the USSR Council of Ministers formally signed a decree (no. 171-83ss) entitled "On Measures to Carry Out in the International Geophysical Year," approving the new proposal. The two new satellites, PS-1 and PS-2, would weigh approximately 100 kilograms and be launched in April-May 1957 after one or two fully successful R-7 launches. Eisenhower's plan to launch an American satellite during IGY was the deciding factor on a launch date. The Object D launch, meanwhile was pushed back to April 1958.
The first three launches of the R-7 ICBM in May-July 1957 were all failures, completely disrupting the schedule to launch a satellite before the beginning of the IGY. There was severe criticism from higher officials and even talk of curtailing the entire program. Back at the launch range of Tyura-Tam, the fourth R-7 launch on 21 August 1957 was successful. The missile and its payload flew 6,500 kilometers, the warhead finally entering the atmosphere over the target point at Kamchatka.
Work on the 'simple satellite' PS-1 had continued at an uneven pace since development of the object began in January 1957. Between March and August, engineers carried out computations to select and refine the trajectory of the launch vehicle and the satellite during launch. These enormously complicated computations for the R-7 program were initially done by hand using electrical arithrometers and six-digit trigonometric tables. When more complex calculations were required, engineers at the OKB-1 were offered the use of a 'real' computer recently installed at the premises of the Academy of Sciences. The gigantic machine filled up a huge room at the department and may have been the fastest computer in the USSR in the late 1950s: it could perform ten thousand operations per second, a high-end capability for Soviet computing machines of the time.
There were many debates on the shape of the first satellite, with most senior OKB-1 designers preferring a conical form since it fit well with the nose cone of the rocket. At a meeting early in the year, the Chief Designer had a change-of-heart and suggested a metal sphere at least one meter in diameter. There were six major guidelines followed in the construction of PS-1:
The satellite as it eventually emerged was a pressurized sphere, 58 centimeters in diameter made of an aluminum alloy. The sphere was constructed by combining two hemispherical casings together. The pressurized internal volume of the sphere was filled with nitrogen at 1.3 atmospheres which maintained an electro-chemical source of power (three silver-zinc batteries), two D-200 radio-transmitters, a DTK-34 thermo-regulation system, a ventilation system, a communications system, temperature and pressure transmitters, and associated wiring. The two radio transmitters operated at frequencies of 20.005 and 40.002 megacycles at wavelengths of 1.5 and 7.5 meters. The signals on both the frequencies were spurts lasting 0.2 to 0.6 seconds, providing the famous 'beep-beep' sound to the transmissions. The antennae system comprised four rods, two with a length of 2.4 meters each and the remaining two with a length of 2.9 meters each. Tests of this radio system were completed as early as 5 May 1957 using a helicopter and a ground station. The total mass of the satellite was 83.6 kilograms of which 51.0 kilograms was simply the power source.
The R-7 that launched Sputnik 1 was transported and installed on the launch pad in the early morning of 3 October escorted on foot by Korolev, Ryabikov, and other members of the State Commission. Fueling began early the following morning at 0545 hours local time. 51 Korolev, under a great amount of pressure, remained cautious throughout the proceedings. He told his engineers, "Nobody will hurry us. If you have even the tiniest doubt, we will stop the testing and make the corrections on the satellite. There is still time..." Most of the engineers, understandably enough, did not have time to ponder over the historical value or importance of the upcoming event. PS-1's deputy designer Ivanovskiy recalled "...Nobody back then was thinking about the magnitude of what was going on: everyone did his own job, living through its disappointments and joys."
On the night of the 4th, huge flood lights illuminated the launchpad as the engineers in their blockhouse checked off all the systems. In the command bunker accompanying Korolev were some of the senior members of the State Commission. All launch operations for Sputnik were handled by two men, a civilian and a military officer. Representing the civilians was Korolev's deputy Leonid A. Voskresenskiy, one of the most colorful characters in the history of the Soviet space program. A daredevil motorcyclist with a legendary penchant for taking risks, he had been with the program since the early days in 1945 when the Soviets had scoured Germany for the remains of the A-4 missile. Lt.-Col. Aleksandr I. Nosov represented the military. Both men were 44 years old at the time. The actual command for launch was entrusted to the hands of Boris S. Chekunov, a young artillery forces lieutenant. He later recalled the final moments as the clock ticked past midnight local time: "When only a few minutes remained until lift-off, Korolev nodded to his deputy Voskresenskiy. The operators froze, awaiting the final order. Nosov, the chief of the launch control team, stood at the periscope. He could see the whole pad. 'One minute to go!,' he called."
With the exception of the operators, everybody was standing. The launch director began issuing commands. The seconds counted down to zero and the launch director shouted the command for lift-off. Chekunov immediately pressed the lift-off button. At exactly 2228 hours 34 seconds Moscow Time on 4 October, the engines ignited and the 272,830 kilogram booster lifted off the pad in a blaze of light and smoke. The five engines of the R-7 generated about 398 tons of thrust at launch. Although the rocket lifted off gracefully, there were problems. Delays in the firing of several engines almost resulted in a launch abort. Additionally, at T+16 seconds, the System for the Simultaneous Emptying of the Tanks (SOBIS) failed, which resulted in higher than normal kerosene consumption. A turbine failure due to this resulted in main engine cut-off one second prior to the planned moment. Separation from the core stage, however, occurred successfully at T+324.5 seconds, and the 83.6 kilogram PS-1 successfully flew into a free-fall elliptical trajectory. The first human-made object entered orbit around the Earth inaugurating a new era in exploration.
U.S. Orbital Program
People the world over speak of the `Space Age' as beginning with the launching of the Russian Sputnik on 4 October 1957. Yet Americans might well set the date back at least to July 1955 when the White House, through President Eisenhower's press secretary, announced that the United States planned to launch a man-made earth satellite as an American contribution to the International Geophysical Year (1957). If the undertaking seemed bizarre to much of the American public at that time, to astrophysicists and some of the military the government's decision was a source of elation: after years of waiting they had won official support for a project that promised to provide an invaluable tool for basic research in the regions beyond the upper atmosphere. Six weeks later, after a statement came from the Pentagon that the Navy was to take charge of the launching program, most Americans apparently forgot about it. It would not again assume great importance until October 1957.
In the decade before Sputnik, laymen tended to ridicule the idea of putting a man-made object into orbit about the earth. Even if the feat were possible, what purpose would it serve except to show that it could be done? Indeed until communication by means of radio waves had developed far beyond the techniques of the 1930s and early 1940s, the launching of an inanimate body into the heavens could have little appeal for either the scientist or the romantic dreamer. And in mid-century only a handful of men were fully aware of the potentialities of telemetry.
Only a mighty rocket could reach beyond the blanket of the earth's atmosphere; and in the United States only the armed services possessed the means of procuring rockets with sufficient thrust to attain the necessary altitude. At the same time a number of officers wanted to experiment with improving rockets as weapons. Each group followed a somewhat different course during the next few years, but each gave some thought to launching an `earth-circling spaceship,' since, irrespective of ultimate purpose, the requirements for launching and flight control were similar. The character of those tentative early plans bears examination, if only because of the consequences of their rejection.
Project Rand mathematicians and engineers declared technology already equal to the task of launching a spaceship. The ship could be circling the earth, they averred, within five years, namely by mid-1951. They admitted that it could not be used as a carrier for an atomic bomb and would have no direct function as a weapon, but they stressed the advantages that would nevertheless accrue from putting an artificial satellite into orbit: `To visualize the impact on the world, one can imagine the consternation and admiration that would be felt here if the United States were to discover suddenly that some other nation had already put up a successful satellite.'
With the outbreak of the Korean War, the tempo of missile research heightened in the Defense Department. While the Navy was working on a guided missile launchable from shipboard and a group at NRL on radio interferometers for tracking it, rocketeers at Redstone Arsenal in Alabama were engaged in getting the `bugs' out of a North American Aviation engine for a ballistic missile with a 200-mile range, and RAND was carrying on secret studies of a military reconnaissance satellite for the Air Force.
Without attempting to describe the type of launching vehicle that would he needed, the RAND study spelled out the reasons why space exploration would bring rich rewards. Six appendixes, each written by a scientist dealing with his own special field, pointed to existing gaps in knowledge which an instrumented satellite might fill. Ira S. Bowen, director of the Palomar Observatory at Mt. Wilson, explained how the clearer visibility and longer exposure possible in photoelectronic scanning of heavenly phenomena from a body two hundred miles above the earth would assist astronomers. Howard Schaeffer of the Naval School of Aviation Medicine wrote of the benefits of obtaining observations on the effects of the radiation from outer space upon living cells. In communications, John R. Pierce, whose proposal of 1952 gave birth to Telstar a decade later, discussed the utility of a relay for radio and television broadcasts. Data obtainable in the realm of geodesy. according to Major John O'Keefe of the Army Map Service, would throw light on the size and shape of the earth and the intensity of its gravitational fields, information which would be invaluable to navigators and mapmakers. The meteorologist Eugene Bollay of North American Weather Consultants spoke of the predictable gains in accuracy of weather forecasting. Perhaps most illuminating to the nonscientifically trained reader was Homer E. Newell's analysis of the unknowns of the ionosphere which data accumulated over a period of days could clarify.
To summarize, the benefits of satellites:
Confusing and complex happenings in the atmosphere, wrote Newell, were `a manifestation of an influx of energy from outer space. What was the nature and magnitude of that energy? Much of the incoming energy was absorbed in the atmosphere at high altitudes. From data transmitted from a space satellite five hundred miles above the earth, the earth-hound scientist might gauge the nature and intensity of the radiation emanating from the sun, the primary producer of that energy. Cosmic rays. meteors, and micrometeors also brought in energy. Although they probably had little effect on the upper atmosphere, cosmic rays, with their extremely high energies, produced ionization in the lower atmosphere. Low-energy particles from the sun were thought to cause the aurora and to play a significant part in the formation of the ionosphere. Sounding rockets permitted little more than momentary measurements of the various radiations at various heights, but with a satellite circling the earth in a geomagnetic meridian plane it should be possible to study in detail the low-energy end of the cosmic ray spectrum, a region inaccessible to direct observation within the atmosphere and best studied above the geomagnetic poles. Batteries charged by the sun should be able to supply power to relay information for weeks or months.
Contrary to what an indifferent public might have expected from rocket `crackpots,' the document noted that `to create a satellite merely for the purpose of saying it has been done would not justify the cost. Rather, the satellite should serve useful purpose-purposes which can command the respect of the officials who sponsor it, the scientists and engineers who produce it, and the community who pays for it.' The appeal was primarily to the scientific community, but the intelligent layman could comprehend it. and its publication in an engineering journal in February 1955 gave the report a diversified audience.
In 1949, tests began on the new sounding rocket built for NRL by the Glenn L. Martin Company. Named `Neptune' at first and then renamed `Viking,' the first model embodied several important innovations: a gimbaled motor for steering, aluminum as the principal structural material, and intermittent gas jets for stabilizing the vehicle after the main power cut off. Reaction Motors Incorporated supplied the engine, one of the first three large liquid-propelled rocket power plants produced in the United States. Viking No. 1, fired in the spring of 1949, attained a 50-mile altitude; Viking No. 4, launched from shipboard in May 1950, reached 104 miles. Modest compared to the power displayed by the Bumper-Wac, the thrust of the relatively small single-stage Viking nevertheless was noteworthy.
While modifications to each Viking in turn brought improved performance, the Electron Optics Branch at NRL was working out a method of using ion chambers and photon counters for x-ray and ultraviolet wavelengths, equipment which would later supply answers to questions about the nuclear composition of solar radiation. Equally valuable was the development of an electronic tracking device known as a `Single-Axis Phase-Comparison Angle-Tracking Unit,' the antecedent of `Minitrack,' which would permit continuous tracking of a small instrumented body in space. When the next to last Viking, No. 11, rose to an altitude of 158 miles in May 1954, the radio telemetering system transmitted data on cosmic ray emissions, just as the Viking 10, fired about two weeks before, had furnished scientists with the first measurement of positive ion composition at an altitude of 136 miles.
This remarkable series of successes achieved in five years at a total cost of less than $6 million encouraged NRL in 1955 to believe that, with a more powerful engine and the addition of upper stages, here was a vehicle capable of launching an earth satellite.
In 1955 President Eisenhower announced that the United States planned to launch a small unmanned earth orbiting satellite as part of the country's participation in the International Geophysical Year that was to run from mid-1957 to mid-1958. The US Navy's proposal, entitled Vanguard, was selected among those submitted by the three services. The Naval Research Laboratory was given overall responsibility for the project while funding came from the National Science Foundation. The Glenn L. Martin Company, which had built the Navy's Viking rocket, was prime contractor for the launch vehicle and its operation.
The satellite proper was built at the Naval Research Laboratory in Washington. The payload for the Test Vehicle (TV) series consisted of seven mercury cell batteries (in a hermetically sealed container), two tracking radio transmitters, a temperature sensitive crystal, and six clusters of solar cells on the surface of the sphere. The two radio transmitters would allow earth stations to track its flight; this would allow scientists to obtain data on the Earth's shape and variations in its gravitational field.
Six 12-inch antennas projected perpendicularly from the surface of the sphere, with three each disposed symmetrically in each hemisphere prior to launch. Approximately 2-inch square solar cells are attached to the surface of the sphere between each pair of antennae. A container inside the sphere holds mercury batteries and two radio transmitters. Separation from the launch rocket was achieved by a strap and pull-in pin method. An acceleration-activated timing motor released a retaining pin, which began the separation and activated the batteries.
The Vanguard team was still working on a test vehicle (TV-2) designed to test the first stage of the rocket when they learned of the launch of the world's first artificial satellite, Sputnik I, by the USSR on October 4, 1957. On December 2, the Department of Defense announced the imminent launch of TV-3.
The scheduled countdown began shortly after 5 PM on December 5; the first stage was ignited at 11:45 AM on December 6. The rocket rose about four feet into the air and immediately sank back down and exploded. The payload nosecone detached in the process and landed free of the exploding rocket. The satellite, too damaged for further use, was salvaged.
On March 17, 1958, the program successfully launched the Vanguard satellite, TV-4. This satellite was identical to TV-3BU, also in the NASM collection, which was the backup for TV-3. TV-4 achieved a stable orbit with an apogee of 2466 miles and a perigee of 404 miles; it was estimated that it would remain in orbit for 240 years. The radio continued to transmit until 1965. Tracking data obtained with this satellite revealed that the earth is not quite round--it is elevated at the North Pole and flattened at the South Pole. The Vanguard program was transferred to NASA when that agency was created in mid-1958. The program ended with the launch of Vanguard 3 in 1959.
While Project Vanguard had been officially "phased out" by NASA's first anniversary, the project left an invaluable legacy whose influence is still seen to this day. Even before the project's first successful launch, Vanguard's upper stages had been modified for use on the Thor-Able which launched the nation's first Moon probes. By the end of the Vanguard program, plans were already well underway to use these same stages with the Atlas-Able to launch NASA's new series of Pioneer probes to the Moon and beyond. The Thor-Able hardware would later be significantly modified to become the famous Delta launch vehicle whose descendants still fly today. The X-248 rocket motor would also be used in NASA's low-cost Scout solid propellant satellite launcher. The Vanguard satellite hardware itself would also prove to be valuable. Much of the hardware (e.g., telemetry systems, tracking beacons, miniature tape recorders, etc.) developed for the program had already been "borrowed" by other satellite programs and future satellite hardware would be based on this newly proven technology. Vanguard's network of tracking facilities would serve as the basis of NASA's worldwide tracking network. Management techniques developed run the project were also adopted by NASA. The list goes on and on. Although Project Vanguard often gets pushed aside because of its poor flight record of only three successes in 11 attempts, it left a powerful legacy that immeasurably aided America's push into space.
The Vanguard field crew was still struggling at Cape Canaveral to put up TV-2, its third test vehicle-the one designed to test the first stage, when on Friday, 4 October 1957, the news broke that Sputnik I, a 184-pound sphere had been launched about 5:30 p.m. that day by the Soviet Union and was circling the earth. Earlier in the week, on Monday, 30 September, scientists representing the Soviet Union, the United States, and five other nations had assembled at the National Academy of Sciences in Washington, D.C., for a six-day conference on the rocket and satellite activities of the International Geophysical Year. A speaker at the opening session was Sergei M. Poloskov, member of the Soviet delegation. Poloskov's subject was "Sputnik," the Russians' word for "traveling companion" and the name they had chosen for the satellite they were preparing to launch. The U.S.S.R. had long since served notice of its intent to develop a satellite-launching program as one of its contributions to the IGY. Nevertheless, there was a stir among Poloskov's listeners when he used an expression that could be literally translated as "now, on the eve of the first artificial earth satellite."
It was a gracious and dignified beginning to a period of mental turmoil and vocal soul-searching in the United States that can scarcely be described as dignified. In retrospect it is easy to smile at some of the exaggerated alarms and groundless assumptions that filled newspaper columns and trumpeted from public platforms as the significance of the Soviet feat became apparent. The smug chuckle of hindsight, however, cannot efface either the importance of the event or the intensity of the change it wrought in American thinking. Girdling the earth once every 96.17 minutes, the first Russian satellite-later referred to as Sputnik I to distinguish it from its successor-was a sphere approximately twenty-two inches in diameter, made of aluminum alloys and equipped with four spring-loaded whip antennas. The satellite itself would fall from orbit on 4 January 1958. "Sputnik night," as the night of 4-5 October 1957 came to be called, was an historic watershed. Almost immediately two new phrases entered the language-"pre-Sputnik" and "post-Sputnik." In England the London Daily Mirror proclaimed the birth of the "Space Age" in huge headlines, and changed its slogan to claim, not the "biggest daily sale in the world" but the "biggest in the Universe." Gone forever in this country was the myth of American superiority in all things technical and scientific. The Russian success alerted the American public to deficiencies in their school system, to the need for providing their young people with an educational base wide enough to permit them to cope with the multiplying problems of swift technological change.
Within hours after the first Soviet launch, the Senate Preparedness Subcommittee chairmanned by Lyndon B. Johnson initiated a "full, complete, and exhaustive inquiry into the state" of the nation's satellite and missile efforts. On 9 October Hagen and Admiral Bennett went "up the Hill" to tell the Vanguard story to attorney Edwin L. Weisl of New York, the Johnson subcommittee's chief investigator, and his staff. Accompanying them was Brigadier General Austin W. Betts of the Department of the Army, whose task was to answer questions concerning the possibility, then under intensive discussion, of using the Army's Jupiter C, a version of its intermediate-range ballistic missile, as the basis of a backup satellite-launching program for Project Vanguard. Most of the Senate investigators' questions reflected current criticisms of the manner in which the United States had handled its satellite program. Considerable discussion dealt with the President's order that the satellite effort be kept "separate and distinct" from the country's military missile effort. There were rocket men in and out of the Army who viewed this arrangement as an inadvisable "division of the indivisible." In answer to the Senate investigators' queries, Hagen and Bennett explained that "the decision" to separate the two programs arose from the fear that "the military program might be delayed if this were not done." They added that subsequent to the separate-but-highly-unequal decision, it had become "apparent that the Jupiter C missile of the Army" could be "used as a booster for an earth satellite. However, the time required to make the necessary modifications to the Jupiter C would not have resulted in a material saving in time and might have reduced the scientific value of the earth satellite." The investigators concluded the session with a request that the Vanguard managers supply them with a report on the background, status, and plans of the project. During the preceding summer, fortunately, Hagen had directed his aides to prepare a chronological history of the project. Within a reasonably short time, this and other pertinent material were on their way up the Hill, to be digested by the Johnson subcommittee staff in preparation for a projected series of hearings by the subcommittee itself.
What must have been welcome news to many anxious Americans came five days after Sputnik II with an announcement from the Pentagon that the Army Ballistic Missile Agency (ABMA) at Redstone Arsenal in Huntsville, Alabama, a unit commanded by Major General John B. Medaris, had received permission to participate in the American satellite program on a backup basis. "The Secretary of Defense today," the department's 8 November release read in part, "directed the Department of the Army to proceed with launching an earth satellite using a modified Jupiter C. This program will supplement the Vanguard program.... The decision to proceed with the additional program was made to provide a second means of putting into orbit, as part of the IGY program, a satellite which will carry radio transmitters compatible with minitrack ground stations and scientific instruments selected by the National Academy of Sciences."
Some of them had been discussing the feasibility of such a move since the fall of 1955 when the Stewart Committee rejected Project Orbiter, the Army's satellite-launching proposal, in favor of the Navy proposal that had become Project Vanguard. For Project Orbiter the Army-directed rocket team headed by Wernher von Braun had designed a four-stage launching vehicle, to consist of the liquid-fueled Redstone rocket, the Army's short-range tactical missile, and three solid stages made up first of clusters of Loki and later of scaled-down Sergeant rockets. When subsequently the Army rocket experts embarked on a series of tests designed to bring their nosecones safely back into the atmosphere during flight, common sense dictated that they use the four-stage vehicle they had planned for Project Orbiter as the basis for creating a suitable test missile. To this end they had developed what by 1957 was known as the Jupiter C, the "C" standing for "Composite Re-entry Test Vehicle," In this way the Army was able to carry on its vehicle development under military priority, an advantage denied the Vanguard program. Had the Jupiter missile been chosen in the first place as the IGY vehicle, it too might have had to undergo development outside military priority. Created by the Army in collaboration with the Jet Propulsion Laboratory of the California Institute of Technology, the Jupiter C was an elongated Redstone with three solid-fuel upper stages-two of them live, and the top one filled with sand to preserve the balance of the vehicle.
The addition to the American satellite effort of the Army team-the Army Ballistic Missile Agency (ABMA) at Redstone Arsenal in Huntsville, Alabama, and its partner, the Jet Propulsion Laboratory (JPL) of the California Institute of Technology in Pasadena-called for a series of high-level decisions in Washington. Some dealt with the scheduling of launches. This was an involved maneuver since both the Vanguard and Army teams would be using the same Cape Canaveral range. They would also be using much the same tracking, telemetry and orbit-computation systems, namely those that the Vanguard electronics experts had developed for their project, supplemented by microlock, a tracking and telemetry network that the Army had been using with its missiles since 1953. Because of these overlaps, sufficient time had to elapse between shots for AFMTC to prepare the requisite range support and for the units in charge of the electronics services to put their equipment in order. Complex as these arrangements were, most of them had been worked out by the end of 1957. By this time the Department of Defense had authorized the Army team to make two "earnest tries" to orbit a small cylinder-shaped satellite to be known as "Explorer," and the Naval Research Laboratory had transferred to the Army a scientific experiment that it had originally assembled for one of the Vanguard satellites. Scientists at the Jet Propulsion Laboratory were modifying this instrumentation for use in the Army payload, and the Army's four-stage Jupiter C missile had reached Cape Canaveral, where a field crew was readying it for erection on the firing table at launch complex 26A, one of the Redstone pads at AFMTC. In addition, the Army had selected 29 January 1958 for its initial launch attempt, with the understanding that the Vanguard team would try to put up another of its vehicles earlier that month.
Since AFMTC could provide range support for only one shot at a time, this left the Army team with a discouragingly short period-less than a week-in which to make its first launch attempt. Fortunately its preflight preparations at Cape Canaveral were not excessively demanding. The Jupiter C had undergone several flight tests. Moreover, such static tests as the forthcoming attempt necessitated had been taken care of at Redstone Arsenal before the missile moved east. The major activities at the pad consisted of checking out the hazardous solid-propellant upper stages of the vehicle and of making sure that when the tub containing these rockets started to spin on top of the elongated Redstone booster, it would do so smoothly and without destructive vibration. Well in advance of the scheduled launch date, these procedures had been concluded, and preparations for the flight test itself were moving at a satisfactory rate.
Advance publicity was restrained and the launch date was withheld from the press until twenty-four hours prior to the anticipated firing. This policy reflected the determination of General Medaris, the ABMA commander, to protect the Army team as much as possible from the misleadingly optimistic type of attention that the press had heaped on Project Vanguard prior to the TV-3 explosion. Summoned to Washington in late 1957 and again in early 1958 to testify at the Johnson Senate subcommittee hearings on American missile and satellite programs, the general ducked the questions of reporters looking for more specific information. The Senate subcommittee itself gave him no problems on this score. When the matter of the Army's launch schedule came up, Cyrus Vance of the investigating staff informed Medaris that "I am not going to ask you about the date." Medaris' reply was "I am thankful for that, Sir." Appearing before the subcommittee on three occasions, the striking-looking ABMA chief was a colorful and articulate witness and both the senators and their staff handled him with a gentleness that must have made John Hagen, the beleaguered Vanguard director, sigh with envy.
On 29 January, launch day, the Explorer vehicle, its satellite and its field crew were ready, but disturbing reports were coming in from the AFMTC meteorologists. On the surface the weather was fine. Instrumented-balloon soundings, however, had revealed the presence high above the Cape of a jet stream, a swiftly-moving river of air, almost certain to destroy the missile. Heeding a teletyped advisory from his structural analysis engineers at Redstone Arsenal, Medaris decided to play it safe. Next mornings weather reading was slightly more encouraging. At noon he authorized the crew to begin an eight-hour countdown, only to call it off a few hours later following a report that the jet stream was again menacing.
At this point-Thursday evening, 30 January-time was running out for the Army team. Project Vanguard's next flight test of TV-3BU was still tentatively set for 3 February, and word from ICY headquarters in Washington was that the electronics units would need three days of preparation for it. The Army must either put up its vehicle on the following day-31 January-or hold off until the Vanguard team had completed its scheduled attempt. Medaris and his crew could only wait and hope. Next mornings 7 o'clock weather reading, as interpreted by the structural analysis engineers, was just favorable enough. "Things look good," it read. "The jet stream has moved off to the north, and by evening should be down to 100 knots." To Medaris that "still sounded like a lot of wind, but it meant the difference between a strain that we knew the missile could stand and one that was dangerous." In a now-or-never spirit, the ABMA commander set in motion another eight-hour countdown, prayerfully heading, as on the day before, for a firing at 10:30 that evening.
Beginning at 1:30 p.m., the countdown encountered no serious hitches. Late in the afternoon there was a half-hour hold to complete a number of operations that had fallen behind schedule, seemingly because crew members were still suffering from exhaustion after the exertions of the day before. Later they made up for the lost time. At 9:45 p.m., with the countdown exactly on schedule, there was a second hold when someone spotted a hydrogen-peroxide leakage in the tail of the missile. Workmen drained the line and stopped the leak. When at 10 p.m. the countdown resumed, it was only 15 minutes behind. At T-12 seconds-X-12, in Army terminology-the motors started to spin the top stages of the vehicle, technicians in the control room of the Redstone blockhouse transferred power from the ground power supplies to onboard sources, and at 10:48 p.m. the Jupiter C lifted off. It rose smoothly from its firing stand. A complex rocket, however, can fail even after a perfect start. There were jittery moments for the crew members while they awaited assurance that the upper stages had fired. For its later satellite-bearing missiles, ABMA would contrive an onboard system capable of igniting the upper stages automatically. No such system flew with the first Explorer missile because the ABMA scientists and engineers had not yet contrived a dependable one. Instead they had developed a method for ground-command firing the second stage at almost the precise second the missile reached its absolute apex following liftoff. This was done from the Redstone hangar. There, at an exactly and swiftly calculated moment, approximately 404 seconds after launch, a scientist pushed a button to fire the second stage. A simple timer then controlled the ignition of the third and fourth stages, operating so as to allow the full thrust of each to be applied before the next one fired.
Word that the upper stages had fired in response to ground command marked the start of still another period of nervous waiting and wondering. Was the satellite in orbit? Tracking stations on the West Coast would have to answer that. One or more of them would be the first to pick up the radio signal showing that the payload had circled the globe. General Medaris has described with understandable feeling the moment when "someone came up and shoved a piece of paper in my hands on which were these magic words: Goldstone has the bird." This meant that at 12:51 a.m., 1 February 1958-one hour and fifty-three minutes after liftoff-a newly installed tracking station in California had picked up the satellite "on its first trip back around over the United States." The big headlines in that mornings newspapers invoked an all but audible sigh of relief across the country. The challenge of the Russian Sputniks had been met. America's first artificial satellite, Explorer I, was orbiting the earth.
The science instruments on Explorer I consisted of a cosmic ray detector, internal and external temperature sensors, a micrometeorite impact detector, and instruments to determine micrometeorite erosion. The cosmic ray detector was designed to measure the radiation environment in Earth orbit. Once in space this experiment, provided by Dr. James Van Allen of the State University of Iowa, revealed a much lower cosmic ray count than expected. Van Allen theorized that the instrument may have been saturated by very strong radiation from a belt of charged particles trapped in space by Earth's magnetic field. The existence of these radiation belts was confirmed by another U.S. satellite launched two months later, and they became known as the Van Allen Belts in honor of their discoverer.
Explorer 1 revolved around Earth in a looping orbit that took it as close as 354 kilometers (220 miles) to Earth and as far as 2,515 kilometers (1,563 miles). It made one orbit every 114.8 minutes, or a total of 12.54 orbits per day. The satellite itself was 203 centimeters (80 inches) long and 15.9 centimeters (6.25 inches) in diameter. Explorer 1 made its final transmission on May 23, 1958. It entered Earth's atmosphere and burned up on March 31, 1970, after more than 58,000 orbits. The satellite weighed 14 kilograms (30.8 pounds).
Sputnik 2 and 3
The foremost practical outcome of their cooperative labors was that the American tracking teams were ready when on 3 November 1957 the Russians sent their second satellite, Sputnik II, into orbit.
Unlike its predecessor, the second Soviet moon was not a special device, orbiting apart from its carrier. It was the last stage of the launching vehicle. Circling the world once every 103.7 minutes, Sputnik II had an apogee of 1,038 miles, a perigee of 140 miles. It remained in space 162 days, falling into the earth's atmosphere on 14 April 1958. Weighing at least 1,120 pounds, it carried the 11-pound test dog, Laika (barker in Russian), in a sealed compartment, along with instrumentation for measuring cosmic rays, solar ultraviolet and x-radiation, temperature, and pressures. Although its transmitters functioned only seven days, they supplied the world scientific community with disclosures concerning the biomedical effect of space travel on animal life, solar influence on upper atmosphere densities, and the shape of the earth.
This time the satellite weighed 508.3 kilograms. Biological data was returned for approximately a week (the first data of its kind). The data showed scientists how Laika was adapting to space -- information important to the manned missions already being planned. There was no safe re-entry possible at the time, so Laika was put to sleep. The satellite itself remained in orbit 162 days.
The third Sputnik satellite was launched on April 27, 1958, but it failed to reach orbit. It was destroyed 88 seconds after launch. It was not given a numeric designation.
Sputnik 3 was launched on May 15, 1958. It was designed to be a geophysical laboratory, performing experiments on the Earth's magnetic field, radiation belt, and ionosphere. It weighed 1,327 kilograms. The data was used as part of the International Geophysical Year efforts. The satellite orbited Earth and transmitted data until April 6, 1960. However, its tape recorder failed rendering it unable to map the Van Allen belts.