Sputnik 1. The first in orbit.
I begin my blog about the history of astronomy and space exploration with a post about Sputnik, the first artificial satellite.
Credit: Smithsonian National Air and Space Museum
In 1948, Mikhail Tikhonravov (1900–1974), then a deputy chief of a secret Soviet NII-4 research institute, started to make proposals for the construction of multistage rockets for long-range missiles and satellites. The reactions for his reports were initially skeptical, but they piqued the interest of Sergei Korolev (1907–1966), the future chief designer of the Soviet space program at Design Bureau No. 1 (OKB-1). In January 1954, NII-4 officially initiated project to create an artificial Earth satellite. In May 1954 the project received approval from the Presidium of the Academy of Sciences and Korolev submitted a proposal "On the artificial satellite of the Earth" to the Minister of the Defense Industry, Dimitri Ustinov (1908–1984).
On July 29, 1955, U.S. President Dwight Eisenhower (1890–1969) announced the intention of the United States to launch a satellite during International Geophysical Year (July 1957 – December 1958). In response, on August 8, the Presidium of the Central Committee of the Communist Party of the Soviet Union approved the proposal "On the creation of the Earth's artificial satellite".
On January 30, 1956, the Council of Ministers approved the development of a satellite code-named Object D, with a mass of 1,000 to 1,400 kg and carrying 200 to 300 kg of scientific instruments to study geophysical phenomena. The launch was scheduled for 1957. The project proved to be overly ambitious due to problems with the development of scientific instruments. Object D was later launched as Sputnik 3 in May 1958.
Fearing the U.S. would launch a satellite before the USSR, OKB-1 suggested in November 1956 the creation and launch of a simple satellite in April–May 1957, before the International Geophysical Year began. The proposal is attributed to Tikhonravov. The new satellite would be simple, light (about 100 kg), and easy to construct, forgoing the complex, heavy scientific equipment in favour of a simple radio transmitter. On February 15 (or February 7), 1957, the Council of Ministers of the USSR approved this simple satellite, designated 'Object PS', PS meaning "prosteishiy sputnik", or "the simplest satellite". The satellite was designed by a team of Mikhail Khomyakov (chief designer), Maksim Khramov (chief designer of the satellite bus) and Oleg Ivanovskiy (pre-flight testing). Its final integration started in August 1957.
Sputnik 1 (PS-1, Russian: Спутник 1 or
Простейший Спутник-1), the world’s first artificial
satellite, was launched from Tyuratam (now the Baikonur
Cosmodrome) Site 1/5 in Kazakh S.S.R. at 19:28:34 UTC on
October 4, 1957, aboard a two-stage Sputnik 8K71PS (no.
M1-PS) rocket, a variant of the R-7 intercontinental
ballistic missile. Compared to the military R-7 test
vehicles, the mass of 8K71PS was reduced from 280 to 272.8
tonnes.
A fuel regulator in the booster failed around
16 seconds into launch, which resulted in excessive kerosene
fuel consumption and the engine thrust being four percent
above nominal. Core stage cutoff was intended for T+296
seconds, but the premature propellant depletion caused
thrust termination to occur one second earlier when a sensor
detected overspeed of the empty turbopump. The satellite
separated 314.5 seconds after the launch. The fairing
separated from both Sputnik and the spent R-7 core stage at
the same time as the satellite was ejected.
The rocket with the satellite was programmed to
enter a 223 km × 1,450-kilometer orbit. As a result of the
premature engine shutdown, the satellite entered an
elliptical orbit below the nominal one, circling Earth every
96.2 minutes, with a perigee 228 km, an apogee 947 km, and
an inclination 65.10° (according to other sources 223 km ×
950 km or 215 km × 939 km).
The satellite was a 58.0 cm-diameter
aluminum sphere with a thickness of 2 millimeters that
carried four whip-like antennas that were 2.4-2.9 m long. It
was filled with dry nitrogen, pressurised to 1.3 atm. The
spacecraft obtained data pertaining to the density of the
upper layers of the atmosphere and the propagation of radio
signals in the ionosphere. The instruments and electric
power sources were housed in a sealed capsule and included
transmitters operated at 20.005 and 40.002 MHz (about 15 and
7.5 m in wavelength), the emissions taking place in
alternating groups of 0.3 s in duration. The downlink
telemetry included data on temperatures inside and on the
surface of the sphere. The energy was supplied by three
silver-zinc batteries with a mass of 51 kg. The launch mass
of the satellite was 83.6 kg.
Sputnik 1 transmitted temperature data for 22
days before its batteries ran out on October 26, 1957. The
spacecraft’s orbit decayed during the following weeks, and
it was destroyed during reentry into the Earth's atmosphere
on January 4, 1958, after 92 days in space and 1,440 orbits.
The Sputnik 1 rocket booster — the core stage
of the R-7 rocket — also reached Earth orbit and was visible
from the ground at night as a first magnitude object, while
the small but highly polished sphere, barely visible at
sixth magnitude, was more difficult to follow optically. The
stage made 882 orbits and reentered on December 2, 1957.
Sputnik 1 was not immediately used for Soviet propaganda. During Sputnik's first orbit, the official Soviet news agency TASS announced: "As result of great, intense work of scientific research institutes and design bureaus the first artificial Earth satellite was created". Soviet newspapers underplayed the achievement, at first, keeping the satellite out of the headlines and reporting its launch in a brief, matter-of-fact account. Only after seeing the American and international reaction the Soviet media sought to press this propaganda advantage. The headline “World’s First Artificial Satellite of Earth Created in Soviet Nation” was splashed across the front of the Soviet Communist Party’s official newspaper Pravda on October 6, 1957. They emphasized pride in the achievement of Soviet technology, arguing that it demonstrated the Soviets' superiority over the West. Soviet media also detailed the frequencies and wavelengths on which Sputnik was emitting regular beeps, saying its transmitters were powerful enough for amateur radio operators to be able to receive them.
President Eisenhower was not surprised by Sputnik 1. He had been forewarned of the R-7's capabilities by information derived from U-2 spy plane overflight photos, as well as signals and telemetry intercepts. The Eisenhower administration was even pleased that the Soviets had established a precedent for freely orbiting over other nations before the planned launch of America's secret spy satellites.
The launch of Sputnik 1 surprised however the American public and challenged the belief that their country was technologically ahead of the Soviet Union. This led to a "Space Race" between the two countries. Public reaction to the perceived threat to national security and technological superiority (known as the "Sputnik Crisis") prompted America to take action in the "Space Race". In February 1958, the Advanced Research Projects Agency (ARPA, later DARPA) was established to regain technological superiority, and in July 1958, the National Aeronautics and Space Administration (NASA) was established. U.S. government spending on scientific research and education was also increased under the National Defense Education Act.
References:
Andrew LePage. Sputnik: The Launch of the Space Age. Drew Ex Machina, October 4, 2017
NASA. NSSDCA: Sputnik 1
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