50 Fun Facts About Sputnik 1

On what date was Sputnik 1 launched?

Sputnik 1 lifted off on 4 October 1957 at 19:28 UTC; its beeps were confirmed on the first orbit and the Space Race had begun.

What was Sputnik 1's claim to fame?

Sputnik 1 was the first artificial Earth satellite; its success in October 1957 caught the United States off guard and set off the Space Race.

What does the Russian word 'sputnik' literally mean?

Sputnik means 'fellow-traveller' or travelling companion, built from s- (with) and put' (path); Russians also use it for a spouse, a companion in life.

What shape was Sputnik 1?

The spherical body was deliberately chosen so atmospheric density could be worked out from how its orbit decayed.

How many external radio antennas did Sputnik 1 carry?

Four whip antennas in two pairs, 2.4 and 2.9 metres long, gave an almost spherical radiation pattern so the signal reached the ground whatever way the satellite was pointing.

Roughly how big was Sputnik 1 in diameter?

The polished aluminium-alloy sphere was 58 cm across, about the size of a beach ball, built from two hemispheres sealed with O-rings.

How much did Sputnik 1 weigh?

Sputnik 1 weighed 83.6 kg; more than half of that, 51 kg, was the battery pack, shaped like an octagonal nut with the transmitter sitting in its hole.

For roughly how long did Sputnik 1 transmit its radio signal before the batteries died?

The silver-zinc batteries were expected to last two weeks and ran for about three weeks, the signal falling silent on 26 October 1957.

How long did each of Sputnik 1's orbits take?

Each orbit took 96.2 minutes; at a peak speed of about 8 km/s (18,000 mph) Sputnik circled the Earth roughly 15 times a day.

How many orbits of the Earth had Sputnik 1 completed when it burned up on 4 January 1958?

Sputnik 1 completed 1,440 orbits in its 92 days aloft; its batteries had died after about three weeks, so it circled silently for more than two months.

Who was the chief Soviet rocket scientist who proposed the satellite plan in 1954 and led the programme?

Sergei Korolev, the Soviet chief designer, pushed the satellite idea from 1954 and on launch night waited about 90 minutes to be sure the sphere had completed an orbit.

Which rocket, originally designed as an ICBM, launched Sputnik 1?

The R-7, the world's first intercontinental ballistic missile, was the most powerful rocket of its day; a modified version designated 8K71PS put Sputnik 1 into orbit.

What did the letters "PS" in the project name Object PS stand for?

The simple sphere replaced the heavy, instrument-laden Object D, which was running late and later flew as Sputnik 3.

The heavier, more ambitious Object D that the simple sphere replaced eventually flew under what name?

Object D flew as Sputnik 3 on 15 May 1958, a 1,327 kg orbiting laboratory; in 1957 its instruments were running late, so the simple sphere went first.

What was the launch site, later known as the Baikonur Cosmodrome, called at the time?

The remote proving ground was chosen in 1955 but not completed until 1958.

In which present-day country was Sputnik 1 launched?

The launch site was in the Kazakh Soviet Socialist Republic, at what is now Baikonur.

On which two frequencies did Sputnik 1 transmit?

Sputnik 1 transmitted on 20.005 and 40.002 MHz; its 0.3-second pulses alternated between the two bands, and a change in pulse length would have signalled temperature or pressure trouble.

What gas filled the sealed interior of Sputnik 1?

The sealed sphere held dry nitrogen at 1.3 atmospheres; a barometric switch would have altered the beep pattern if a leak or meteoroid puncture dropped the pressure.

How was Sputnik's internal temperature kept in check?

A dual thermal switch turned the fan off again below 20 °C.

How many R-7 launch attempts failed before the first fully successful flight in August 1957?

The May flight caught fire at liftoff, the June rocket never left the pad, and the July vehicle rolled out of control and crashed 7 km away.

What did the intended orbit's apogee turn out to be compared with the plan?

A fuel regulator failed 16 seconds after launch; the engines ran rich and the core stage cut off a second early, leaving the apogee about 500 km lower than planned.

What did most people who "saw Sputnik" in the night sky actually see?

The tiny polished sphere was only sixth magnitude; the booster trailing behind it was first magnitude and had reflective panels fitted to make tracking easier.

Which British observatory was the only one able to track Sputnik's booster rocket by radar?

Jodrell Bank's 76-metre Mark I telescope, completed only that summer, was the one instrument in the world able to track the booster by radar in 1957.

Which citizen-science project organised teams of visual observers at 150 stations to watch for Sputnik?

Operation Moonwatch, run by the Smithsonian Astrophysical Observatory, had trained volunteer teams with small telescopes to spot satellites at dawn and dusk.

Which university's student radio station was the first to rebroadcast the beeps to the American public?

Columbia University's amateur station W2AEE picked up the signal and students at the campus FM station WKCR taped and rebroadcast it, the first time most Americans heard the beeps.

Which US research agency was created in February 1958 in direct response to Sputnik?

NASA followed later the same year through the National Aeronautics and Space Act.

Which 1958 law, passed after Sputnik, offered low-interest college loans to maths and science majors?

The National Defense Education Act of September 1958 poured federal money into maths, science and language teaching, including low-interest loans for college students.

What was the first successful American satellite, launched on 31 January 1958?

Explorer 1 was built by the Army Ballistic Missile Agency and the Jet Propulsion Laboratory; its Geiger counter data led to the discovery of the Van Allen radiation belts.

Which American launch failed on live television on 6 December 1957, deepening the country's dismay?

Vanguard TV-3 rose about a metre before falling back and exploding on the pad at Cape Canaveral; the press dubbed it 'Flopnik' and 'Kaputnik'.

How had President Eisenhower been forewarned of the R-7's capabilities?

His administration's first response was low-key; he even welcomed the USSR testing the legality of satellite overflights first.

What was the name of the dog carried into orbit by Sputnik 2 on 3 November 1957?

Laika, a stray from the Moscow streets, rode Sputnik 2 on 3 November 1957 and died within hours from overheating; the craft had no way to return.

Which event was the second satellite's launch meant to coincide with?

The Kremlin wanted a second satellite up for the 40th anniversary of the October Revolution on 7 November 1957; Sputnik 2 flew four days early, on 3 November.

Two Johns Hopkins physicists tracked Sputnik by what property of its signal?

William Guier and George Weiffenbach at the Johns Hopkins Applied Physics Laboratory used the Doppler shift of the beeps to work out the satellite's orbit from a single ground station.

Which satellite navigation system, a forerunner of GPS, grew out of tracking Sputnik?

TRANSIT, the Navy's satellite navigation system, first reached orbit in 1960 and let Polaris submarines fix their position; it was the direct forerunner of GPS.

In which US state does a flight-ready backup of Sputnik 1 sit in a museum?

The Cosmosphere in Hutchinson, Kansas, holds a flight-ready backup of Sputnik 1; the other known backup is at the RSC Energia museum near Moscow.

To which organisation did the Soviet Union donate a replica of Sputnik in 1959?

The Soviet Union presented a full-size Sputnik 1 replica to the United Nations in 1959; it is displayed at UN headquarters in New York.

What was the one-third scale, student-built Sputnik replica released from Mir called?

Sputnik 40, built by Russian and French students, was hand-launched from Mir on 3 November 1997 to mark the fortieth anniversary; Sputnik 41 followed a year later.

Which Soviet leader did Korolev telephone once the satellite was confirmed in orbit?

Korolev telephoned Nikita Khrushchev, First Secretary of the Communist Party since 1953, who then pressed for a second satellite within a month.

Which Soviet cosmonaut-to-be calculated Sputnik's trajectory on the Academy of Sciences' mainframe?

Georgi Grechko, later a three-flight cosmonaut, ran the trajectory on the Academy of Sciences' mainframe after earlier work with arithmometers and six-digit trigonometric tables.

Which Soviet design bureau built Sputnik 1?

OKB-1, Korolev's design bureau in Kaliningrad (now Korolyov) near Moscow, built Sputnik 1; its modern descendant is RSC Energia.

What affectionate nickname did Soviet engineers give the R-7 rocket?

Semyorka, 'little seven', was the engineers' pet name for the R-7; the same rocket family was developed into the Soyuz launcher.

What Cold War fear did the Sputnik shock help create in American politics?

The 'missile gap' was the belief that the Soviets led in ICBMs; Democrats such as Stuart Symington and John F. Kennedy pressed it, though satellite reconnaissance later showed it was illusory.

How was Sputnik 1 protected during launch?

The 80 cm fairing came off at the same moment the satellite was ejected from the spent second stage.

How many silver-zinc batteries powered Sputnik 1?

Two ran the transmitter and one the temperature regulation system.

What did the world's amateur radio operators famously hear from Sputnik 1?

The first US recording was made by RCA engineers on Long Island and rushed into Manhattan for NBC.

Sputnik 1 was launched during which worldwide scientific programme of 1957-58?

The International Geophysical Year ran from July 1957 to December 1958; the United States had announced in 1955 that it would orbit a satellite for it, and the Soviets raced to go first.

Sputnik 1's two hemispheres were sealed with O-rings and joined by how many bolts?

The 2 mm shells were covered in a polished 1 mm heat shield of an aluminium-magnesium-titanium alloy called AMG6T.

What was the orbital inclination of Sputnik 1, letting it pass over nearly all inhabited Earth?

Sputnik 1 orbited at 65° inclination, so its ground track reached from 65° north to 65° south, covering nearly every populated region of the Earth.

Roughly how far did Sputnik 1 travel before it burned up?

Sputnik 1 covered about 70 million km in 92 days before aerodynamic drag brought it down on 4 January 1958; the drag itself yielded upper-atmosphere density data.

Which engineer's report, forwarded by Korolev, called a satellite an inevitable step in rocketry?

Mikhail Tikhonravov's 1954 report called an artificial satellite an inevitable step in rocket development; Korolev forwarded it to the Soviet government, and his survey of foreign projects helped win approval.