Humanity’s leap into space was one of the greatest scientific achievements of the twentieth century. However, one of the ironies of history is that this great scientific and engineering achievement was largely facilitated by the Cold War between the two superpowers, the United States and the Soviet Union.
In the late 1950s, the United States held a significant advantage over the Soviet Union in number of nuclear warheads and capability to eliminate the most important strategic facilities on its enemy’s territory. Although the Soviet Union already had nuclear weapons, it did not have second-strike capability because it did not have any delivery vehicles capable of delivering warheads to U.S. territory. The senior political leadership of the Soviet Union assigned its missile science and industry a task of ”special governmental importance’-development of a ballistic missile that could render the United States vulnerable.
The early experimental intercontinental ballistic missiles developed by Soviet scientists and engineers were used to place the first artificial Earth satellites into orbit. Thus, the history behind the development and launching of the first satellite into orbit is primarily the story of a missile that became a launch vehicle for a satellite rather than a missile carrying a weapon of mass destruction.
As long ago as February 1953, a government decree assigned NII-88, the lead institute for missile technology, the task of performing ”theoretical and experimental research related to developing a two-stage ballistic missile and studying the future applications for a missile with a range of 7000-8000 km.” This task wasled by Sergei Korolev, who at that time was the Chief Designer of OKB-1 (at that time part of NII-88). Korolev, for his part, was head of the Chief Designer’s Council, which included the following Chief Designers: Valentin Glushko for rocket motors, Nikolai Pilyugin for trajectory control systems, Vladimir Barmin for ground launch systems, Mikhail Ryazanskii for radio systems, and Viktor Kuznetsov for gyro control devices. The preliminary design for the missile called for developing a 170-metric-ton, two-stage missile with a 3000-kg detachable nose cone. The nose cone was designed to hold a nuclear warhead weighing up to 1000 kg and having an 80-kiloton maximum yield.
However, in 1953, the Soviet Union successfully tested a thermonuclear warhead—the ”hydrogen bomb,” with a yield a few dozen times that of a nuclear warhead. In late 1953, Korolev was ordered to change the design and increase the throw weight to 3000 kg. This required an increase in the total payload mass to 5500 kg. Major revisions in the missile design were required to maintain the desired range specifications.
The basic changes implied by the increased throw weight requirement were as follows:
1. change launch configuration that used the upper load-bearing members of the side-mounted engines as supporting points for the four launch trusses and removed as the missile begins to climb;
2. switch to a high-thrust, four-chamber propulsion system;
3. use movable steering engines in place of exhaust vanes;
4. increase fuel capacity;
5. increase of 38 metric tons in the thrust of each propulsion system;
6. addition of backup gyro control devices;
7. addition of systems to monitor drainage of tanks and synchronization of fuel consumption by the side-mounted engines;
8. development of a fundamentally new launch system that reduced the load on the missile structure, thereby substantially reducing the weight of the missile.
The Government decree ordering development of the R-7 two-stage ballistic missile was approved on 20 May 1954. A subsequent decree provided a schedule and list of deliverables. Flight testing was scheduled for February 1957. Development and fabrication of all systems and the first few missiles took place during 1955-1956.
The missile design represented a fundamental improvement in structure, frame configuration, dimensions and mass, propulsion-system thrust, control actuators, a new dynamic launch system configuration, and new inertial and radio navigation techniques. The missile itself consisted of four side-mounted, first-stage engine assemblies mounted around the central engine assembly of the second stage. The internal design of the side-mounted engine assemblies and central engine assembly were similar to the single-stage designs then in use. The engines used kerosene and liquid oxygen as propellants. All five engine assemblies operated from the ground up and were started almost simultaneously. The side-mounted engines were turned off upon stage separation, and the second stage remained active.
Each engine assembly was based on a standard four-chamber engine with sea-level thrust greater than or equal to 80 metric tons. This package arrangement required a synchronized tank drainage system and an engine-thrust control system. This missile marked the first use of special steering chambers that moved by electrohydraulic actuators in response to commands issued by the control system.
The development process for this missile included extensive experimental testing of individual systems, in addition to experimental testing of the overall design. Final testing of the control system was performed on special M5RD test missiles based on the R-5 missile. Flight testing of 10 M5RD missiles using the new control-system equipment enabled verification of the apparent-speed-control system, the tank drainage system, and a new telemetry system, including the sensor instrumentation (in particular, a vibrational sensor system).
The R-5R test missiles were used for flight testing telemetry-based missile velocity measurements, using a centimeter-wavelength pulsed radio system, radio-wave attenuation in engine jets, and correctness of the underlying design principles for the radio direction finder. Flight testing three R-5R missiles provided a large amount of experimental material that enabled substantial modifications to the instrumentation fabricated for initial flight/design testing of the R-7 missile.
Almost all of the sensor equipment for the onboard instrument system was developed from scratch. In all, seven sets of recording sensors were installed on board the missile. In addition, special ground-based recording equipment was used to monitor the missile launch and the behavior of launch systems. More than 600 in-flight parameters were measured using a total of 2800 kg of onboard instrumentation. Unlike all previously developed single-stage missiles, the R-7 missile and launch fixtures formed a single dynamic system. The launch ground system included more than 30 individual systems and assemblies.
The interfaces between ground systems and missile and the interfaces between individual ground systems were tested using special missile mockups interfaced to the ground systems at the launch facility. However, before this, appropriate system testing of the launch system and missile was performed at the Leningrad Machinery Plant. The missile-lift procedure was simulated using high-capacity lifting cranes and a missile filled with water in place of fuel. It was essential to ensure that the gantries retracted simultaneously and that the missile frame would mechanically mate with the launch system. The complete ground system at the launch site was tested using a simulated R-7 missile, which was repeatedly placed on the launch stand and repeatedly fueled.
The Scientific Research Institute for Firing Tests (NII-229) built several high-capacity rocket test stands for testing the propulsion systems in combination with the missile frame. From August 1956 to March 1957, NII-229 performed five firing tests of the side-mounted engine units, three tests of the central engine unit, and two tests of the complete package of five engine units. The first R-7 missile for flight testing arrived at the Tyuratam support facility (Scientific Test Site NIP-5, the future Baikonur) in March 1957. The horizontal testing performed at the NIP-5 support facility included electrical and pneumatic testing of each engine unit, postshipment verification of engine-unit alignment, assembly of the engine units into a single package, and integration testing of all electrical and pneumatic systems (”horizontal system testing”).
The first meeting of the State Flight Test Committee occurred on 10 April 1957. The Committee was chaired by M.V. Ryabikov, Chairman of the Military Industrial Complex, and had the following members: Chief Marshal of Artillery M.N. Nedelin (Deputy Chairman); Chief Designer S.P. Korolev (Engineering Manager); Chief Designers V.P. Glushko, N.A. Pilyugin, V.P. Barmin, M.S. Ryazanskii, V.I. Kuznetsov, S.M. Vladimirskii (Deputy Chairman, State Committee for Radio Electronics), A.I. Nesterenko (Manager, Scientific Test Site 5), G.N. Pashkov (State Planning Committee [Gosplan]), I.T. Peresypkin (USSR Ministry of Communications), and G.R. Udarov (Deputy Chairman, State Committee for Military Equipment).
The missile was first launched on 15 May 1957. The flight appeared to proceed normally for the first 60 seconds, at which time a fire broke out in the tail compartment. Reduction of the telemetry data revealed that one of the side-mounted engines fell off 98 seconds into the flight, when the missile became unstable. The root cause of the accident turned out to be a leak in a fuel line. Nevertheless, this launch did confirm that the control-system parameters for the first-stage segment were correct and gave us confidence in the launch dynamics.
The second scheduled launch attempt on 11 June 1957 was unsuccessful because the disc on the main oxygen valve for side-mounted unit C froze and an error had been made during installation of the nitrogen blow down valve on the oxidant line for the central engine unit. The missile was returned to the Support Facility.
The third launch was on 12 July 1957. Thirty-three seconds into the flight, the missile became unstable. The root cause of the accident turned out to be a short circuit between the control-signal circuits and the housing in the angular-velocity integrator for the roll channel. The fourth launch on 21 August 1957 was successful, and the missile, for the first time, hit a target on Kamchatka Peninsula. A TASS statement announcing the launch of a long-range, multistage intercontinental ballistic missile was carried by the USSR mass media on 27 August.
The fifth launch of the R-7 missile on 7 September 1957 confirmed the results of the previous launch. However, although the missile components and systems operated normally during the active portion of the flight, the warhead reentry vehicle (RV) broke up upon reentry into the lower atmosphere. A significant amount of time was required for research and development work related to, and fabrication of, new warhead RVs capable of withstanding the high temperatures and large gas-dynamic loads that occurred during the reentry portion of the flight. With the consent of the Government and the State Commission, it was decided to use two of the original twelve R-7 missiles built for development testing as launch vehicles for the first artificial Earth satellites. These launches provided a practical opportunity to accumulate additional experimental data on all missile systems except for the forward compartment containing the nuclear warhead. Thus, these early satellite launches were an integral part and outgrowth of development testing for early intercontinental ballistic missiles.
A fortunate convergence of historical fates in the early 1950s led to the renewal of creative contacts between Sergei Korolev and Mikhail Tikhonravov, his former colleague in development of early perwar unguided missiles during the 1930s. In the late 1940s, Tikhonravov led a group of enthusiasts from the highly classified Scientific Research Institute 4 [NII-4] who were studying designs for space launch vehicles, as well as a variety of issues related to subsequent manned spaceflight. Tikhonravov and his group were the first professional people in the Ministry of Defense system who dared to say that the R-7 intercontinental ballistic missile developed under Korolev’s direction could, with slight modifications, be used as a satellite launch vehicle.
With slight changes to the flight plan, the missile could place a satellite weighing up to 1500 kg into orbit instead of delivering a 5.5-metric-ton nuclear warhead at a range of 8000 km. The Ministry of Defense generals did not support Tikhonravov’s initiative, but Korolev quickly grasped the possibilities for practical implementation of his long-held dream of human spaceflight, and was able to arrange for Tikhonravov’s transfer from NII-4 to OKB-1 (Korolev’s design bureau). In May 1954, Korolev had presented a proposal to the Minister of Armaments (Dmitrii Ustinov), the Council of Ministers, and the USSR Academy of Sciences to develop the world’s first artificial Earth satellite and launch it with the R-7 missile for research purposes. The basic idea contained in Korolev and Tikhonravov’s report was that ”the artificial Earth satellite is an inevitable phase in the development of space hardware, following which interplanetary missions will become possible.”
In August 1954, the USSR Council of Ministers approved a proposal to study the scientific and engineering issues involved in a spaceflight. Korolev had support from the following senior government officials, as well as the Academy of Sciences: Deputy Chairman of the Council of Ministers V.M. Malyshev, D.F. Ustinov, and Ministers B.L. Vannikov, M.V. Khrunichev, and K.N. Rudnev. Despite the military’s fears that development of a spacecraft would be a distraction from the primary tasks involved in developing the R-7 missile, on 30 January 1956, the Council of Ministers approved the development of an unstabilized spacecraft (”Object D”) weighing 1100-1400 kg and carrying 200-300 kg of scientific research instrumentation. The Government gave the USSR Academy of Sciences responsibility for developing the scientific research equipment. The required task orders were issued as directives to the Ministry of Defense Technology (the lead ministry) and all other ministries and organizations involved in missile development and production.
OKB-1 and its subcontractor organizations completed their design work in 1956 and then moved on to fabricate Object D, which was to become the first artificial Earth satellite. Object D was to be used for scientific research in the following areas: density and ionic composition of the high-altitude atmosphere, solar particles, magnetic fields, cosmic rays, temperature conditions within the spacecraft itself, braking of the spacecraft in the upper atmosphere, and the accuracy of spacecraft position and orbit determination. The scientific instrumentation and spacecraft onboard systems were to have been powered by solar panels and storage batteries, and the spacecraft would have had an automatic temperature control system. This spacecraft was also to have been the first recipient of an onboard control system with a special programmable timer. In-flight control of the scientific research program was to have been performed via a radio command link from the ground. A special radio telemetry system was to have transmitted the research results to the ground. An extensive network of ground stations, forming a unified command and telemetry system controlled from a single center at NII-4, was to have been constructed.
By late 1956, it was clear that the schedules for fabricating the scientific instrumentation had slipped, and it became uncertain whether the spacecraft could even be launched during the U.N.-sponsored International Geophysical Year. Because press reports indicated that the United States was also preparing to launch a spacecraft early in the International Geophysical Year, Korolev proposed postponing the launch of Object D and launching a very simple spacecraft, the PS, carrying no scientific instrumentation instead.
On 15 February 1957, the Government accepted the proposal by Korolev and the Academy of Sciences to launch an extremely simple unstabilized Earth satellite (Object PS) to verify that the PS could be observed in orbit and that signals transmitted by the PS could be received, as well as to ensure worldwide priority in the space race. The Government would permit the spacecraft launch to occur only after one or two successful launches of the R-7 missile. The extremely simple satellite (the PS) was designed, fabricated, and prepared for launch using the missile in only 8 months. The launch was scheduled for 6 October. However, intelligence reports from overseas indicated that the Americans were preparing their own satellite for launch in early October, so Korolev sped up the preparations, and the PS was launched on 4 October. The first artificial Earth satellite was launched into space on the fifth launch of the first intercontinental missile. Two of the preceding four launches had been unsuccessful because the problems encountered by the developers of the first intercontinental missile were new.
The goal of this launch was to place an extremely simple satellite into orbit and also to obtain additional experimental data on the dynamics of the missile launch and propulsion systems, the control and guidance systems, the stage separation system, the onboard sensors, the operation of equipment on the ground, and the command and telemetry system on the ground. During the round-the-clock effort to prepare the rocket for launch, several problems were identified and eliminated right on the launch pad. In response to one problem report during rocket fueling, one of the fuel tanks for the side-mounted engines was drained and refilled to test the ”tank full” alarm system.
The guidance system was adjusted to place the missile into an orbit with the following parameters:
perigee: 223 km; apogee: 1450 km; period: 101.5 min.
These orbital parameters could be achieved using half of the guaranteed fuel supply, provided that the guidance systems and all engine systems operated properly. Trajectory measurements indicated that the rocket performed normally during the active portion of the flight. However, the second-stage engine ran out of fuel before it was scheduled to be turned off by the guidance system.
The world’s first artificial Earth satellite was launched into space on 4 October 1957 at 22:28 Moscow time. It ended up in an orbit with the following parameters: perigee; 228 Km: apogee; 947 Km: inclination; 65.1°: and period: 96.17 min. Reduction of the telemetry data enabled collecting a large amount of experimental data concerning operation of the missile, various individual missile systems, and the ground launch systems. The spacecraft weighed 83.6 kg; the body of the spacecraft consisted of a sphere 580 mm in diameter with four collapsible-whip antennas (2.4 m and 2.9 m long). The body of the first artificial Earth satellite consisted of two aluminum alloy hemispheres filled with dry nitrogen (pressure 0.13 MPa); the joint between the two hemispheres was sealed using a rectangular-cross-section, vacuum-grade O-ring. The pressurized enclosure held an electrochemical power source and two radio transmitters that continuously transmitted on 20.005 and 40.002 MHz (wavelength 17 and 7.5 m, respectively). The transmitter signals consisted of alternating telegraph and ”spaces,” each 0.3 s long. The radio transmitter system had a total mass of 3.5 kg, and each transmitter had an output of about 1W. The telemetry data (temperature and interior pressure) were transmitted to the ground by modulating the frequency of the ”space” signals. Each transmitter had two collapsible-whip antennas (approximately 70° apart). Each pair of antennas had a nearly spherical antenna pattern.
The temperature control system had a radiator with a fan-driven, sealed-loop, forced-gas heat exchange system designed to maintain a stable interior temperature in the face of variable external thermal fluxes. The temperature control system used a bimetallic thermal relay as the sensor element. Whenever the temperature increased above 36 °C, the fan came on, and nitrogen circulated through the system to transfer heat away from the hemisphere that was acting as a radiating surface (emission coefficient 0.35-0.4, solar absorption coefficient 0.23-0.4). The fan was turned off whenever the temperature fell below 20°C.
The intended purpose of the automated onboard electrical system was to turn on the electrical power to the instruments, once the spacecraft reached orbit (i.e., upon separation from the launch vehicle). During the launch phase, the spacecraft was placed under a nose cone for protection against aerodynamic and thermal effects; the nose cone was jettisoned when the second-stage engine shut down. The spacecraft carried three silver-zinc batteries weighing 51 kg. The batteries could support operation of the instruments for 3 weeks. The first satellite lasted 92 days, and completed ~ 1400 orbits around Earth. On 4 January 1958, it reentered Earth’s atmosphere and burned up.
The orbital parameters of the first Soviet artificial Earth satellite were such that it was visible from all continents across a wide range of latitudes. Observations of the spacecraft’s motion, reduction of the observations, and prediction of the future motion of the spacecraft based on these results served as an early practical exercise in using ground-based spacecraft control systems and equipment for measuring spacecraft parameters. The first satellite was observed using radio equipment, as well as optical instruments at astronomical observatories. The news that the first artificial Earth satellite had been launched aroused extremely broad interest among radio amateurs and amateur astronomers around the world. In the Soviet Union, 66 optical observing stations and 26 clubs with extensive collections of radio observing gear regularly observed the spacecraft. In addition, thousands of radio amateurs attempted radio observations of the spacecraft. State scientific radio monitoring stations also observed with radar and radio range finder systems. This was the first rich set of statistical data concerning the transmission of meter-wavelength radio waves through the ionosphere and also represented the first opportunity to receive radio signals at two different frequencies from regions of the ionosphere that had heretofore been inaccessible, that is, above the ionization peak or even above the entire ionosphere.
Extremely valuable data were also obtained on radio-wave absorption in previously unstudied layers of the ionosphere, as well as new data on the structure of these regions and the ion concentration at various altitudes and times of day. These systematic measurements showed that the altitude of the main peak in the ionosphere and the peak electron concentration vary from day to night, north to south, and east to west. Radio propagation measurements at the frequencies emitted by the spacecraft at various altitudes provided a new avenue for ionospheric research. These observations led to the discovery that the decrease in electron concentration in the upper ionosphere (above the main peak) with altitude is five to six times slower than the increase with altitude below the peak. For example, when the observations were made (in October), the electron concentration increased by approximately a factor of 10 from 100-300 km altitude, whereas it decreased only by a factor of 2 from 300-500 km in altitude. The initial indications that micrometeoroids were not hazardous to spacecraft was an extremely important result.
The radio methods used included radio ranging and Doppler observations of the radio signal from the spacecraft. These early experiments indicated that the Doppler effect could be used successfully to determine spacecraft orbital parameters. It became obvious that the accuracy of orbit determination could be quite high if the transmitter frequency were increased and if automated frequency measurement equipment were used. Early, high-sensitivity photographic techniques were developed for observing this spacecraft. Image-converter tubes turned out to be especially promising in this regard.
The news that the Soviet Union had launched the world’s first artificial Earth satellite turned out to be quite an unexpected sensation for the entire human community. The flight of the first satellite around Earth caused a stunning resonance around the world. Virtually the entire world press carried front-page banner headlines reporting the news, thereby underlining that Soviet science had taken the lead. The American government was shocked, along with American scientists confident of their superiority. The senior leadership of the Soviet Union was surprised by this enthusiastic reaction from their people and people around the world. Therefore, to consolidate the political success that had been so unexpectedly achieved in the Cold War, the General Secretary of the CPSU Central Committee, Nikita Khrushchev, proposed that Korolev launch a new satellite in honor of the 43rd anniversary of the October Revolution. The first, extremely simple satellite was still operating in orbit, and there was no sense in launching another, similar satellite.
A second spacecraft was readied in less than a month and launched on 3 November 1957. The dog Laika, who later became famous, was the first experimental animal to orbit Earth. The second spacecraft did not separate from the second stage of the rocket, and, for the first time, data on the behavior of a dog in space was transmitted to the ground via a multichannel telemetry link.
Object D, which was to have been the first spacecraft, was not launched until 15 May 1958. It was the third Soviet spacecraft and the first that could truly be called a space laboratory based on the amount of scientific instrumentation on board.
The successful launch of the first artificial Earth satellite marked the beginning of humanity’s journey into space. Many extremely urgent scientific problems required direct experiments at altitudes of hundreds or thousands of kilometers above Earth’s surface. Although the significance of artificial Earth satellites had long been understood, launching them had remained an insoluble problem. The main difficulty had been developing a rocket that could give a spacecraft a velocity of the order of 8000 m/s. Only after the Soviet Union had developed an intercontinental ballistic missile did it become possible for the first time in history to launch an artificial Earth satellite. The superior design of this missile enabled placing a spacecraft with the required weight of scientific instrumentation into orbit. Further improvements of the R-7 missile—in particular, the addition of a third and then a fourth stage led to manned space programs, communications satellites, and the first automated interplanetary spacecraft for studying the Moon, Venus, and Mars. Modernized versions of the R-7 missile are currently used for manned and cargo spacecraft to support the International Space Station.
