50 Fun Facts About Sputnik 1

On what date was Sputnik 1 launched?

It went up during the International Geophysical Year from the Tyuratam range, now the Baikonur Cosmodrome.

What was Sputnik 1's claim to fame?

Its success caught the United States off guard and set off the Space Race.

The Russian word 'sputnik', from s- and putnik, literally means what?

It matches the Latin root satelles, meaning guard or companion, which gave English the word satellite; its everyday meanings include spouse.

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?

They came in two pairs of whip-like rods, 2.4 and 2.9 metres long, giving an almost spherical radiation pattern.

Roughly how big was Sputnik 1 in diameter?

Two hemispheres of aluminium alloy were sealed with O-rings and 36 bolts.

How much did Sputnik 1 weigh?

More than half of that, 51 kg, was the battery pack, shaped like an octagonal nut with the transmitter in the 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 managed 22 days, falling silent on 26 October 1957.

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

It hit a peak speed of about 8 km/s, or 18,000 mph.

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

It had travelled roughly 70 million kilometres; the batteries had died after just 326 orbits.

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

After launch he waited about 90 minutes to be sure the satellite had made one orbit before phoning Khrushchev.

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

It was the most powerful rocket in the world, built with excess thrust because nobody yet knew how heavy a hydrogen bomb would be.

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 was to weigh up to 1,400 kg with 300 kg of instruments, but the R-7 engines underperformed and the instruments were late.

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?

The 0.3-second beeps alternated between the two, and their duration encoded temperature and pressure inside the sphere.

What gas filled the sealed interior of Sputnik 1?

A barometric switch would have altered the beep pattern if the pressure dropped, signalling a leak or meteor puncture.

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 burned rich, and the core stage cut off a second early.

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?

The Lovell Telescope had only just been completed in 1957.

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

Amateur radio operators were also asked by the USSR to tape record the satellite's signal.

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

The signal was picked up by ham station W2AEE and taped by students at the FM station WKCR.

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?

A poll after the launch found 26% of Americans thought Soviet science was superior; a year later that had fallen to 10%.

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

It was built by the Army Ballistic Missile Agency with the Jet Propulsion Laboratory after the televised failure of Vanguard TV-3.

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

The Navy's Vanguard project had been chosen as America's civilian satellite entry for the International Geophysical Year.

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?

Khrushchev had pressed Korolev to launch a second satellite in time for the 40th anniversary of the October Revolution.

Which event did Khrushchev want the launch of the second satellite to coincide with?

The date was 7 November 1957; the second satellite went up four days early.

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

Their work led to the Navy's TRANSIT system, a forerunner of GPS.

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

The Navy needed it to fix the positions of submarines carrying the new Polaris missile.

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

The Cosmosphere in Hutchinson also has an engineering model of Sputnik 2; the other backup is at Energia's museum near Moscow.

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

Other full-size replicas are on show at the Science Museum in London and outside the Russian embassy in Spain.

What was the one-third scale student-built replica released from Mir in November 1997 called?

It marked the fortieth anniversary of the launch; Sputnik 41 and Sputnik 99 followed.

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

The team waited about 90 minutes at a mobile radio station to be certain of a full orbit first.

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

Earlier calculations had been done with arithmometers and six-digit trigonometric tables.

Which Soviet design bureau built Sputnik 1?

Its modern descendant, Energia, keeps one of the backup satellites in a museum near Moscow.

What did the American press call the surge of public and government interest in space after the launch?

One popular book listed seven areas of "impact", from missile production to democratic culture.

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

Democratic politicians portrayed the United States as woefully behind, inflaming the anxiety.

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?

Eisenhower had already promised an American satellite for the same programme, which is why OKB-1 rushed to launch before July 1957.

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?

Its initial orbit ran from 223 km to 950 km, with the apogee about 500 km lower than planned.

Roughly how far did Sputnik 1 travel before burning up after 1,440 orbits?

Aerodynamic drag brought it down on 4 January 1958 after three months aloft; the drag itself yielded data on upper-atmosphere density.

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

His overview of foreign satellite projects helped persuade the leadership to back the programme.