This Week in Rocket History: Sputnik 1

by | Oct 7, 2021 | Daily Space, Space History, Spacecraft | 0 comments

This Week in Rocket History: Sputnik 1
IMAGE: Exploded view of Sputnik. CREDIT: Museum of Cosmonautics, Russia

This week in rocket history features an important milestone in space exploration: the 64th anniversary of the Sputnik 1 launch.

In the mid-1950s, both the Americans and the Soviets were developing large rockets capable of delivering nuclear warheads to locations thousands of kilometers away. In 1954, Sergei Korolev, head of the main Soviet rocket development bureau, and Mikhail Tikhonravov, an early pioneer in rocket development, presented a report stating that the launch of an artificial satellite into Earth orbit was an inevitable use of rocket technology and that the Soviets should do this first.

The very next year, 1955, the United States announced that they were going to launch a satellite during the International Geophysical Year in 1957. Less than a week after that announcement, Korolev’s plan was approved by the Soviet government.

With official permission secured, Korolev’s Design Bureau, OKB-1, set to work designing his satellite. What they came up with was astounding. The satellite would weigh 1.4 metric tons – or about the same as a beluga whale. Two hundred kilograms — that’s 100 two-liter soda bottles — of that was just the science instruments. The preliminary design of the satellite was completed in July 1956, with its launch also planned to take place during the International Geophysical Year in 1957.

By the end of 1956, the Soviet scientists realized that this large satellite, officially called Object D, would not be ready for the International Geophysical Year. So they put that work on hold and began designing the simplest satellite possible to launch during the International Geophysical Year.

In February 1957, the new satellite was approved as Object PS, or “Simplest Satellite”. It was a highly polished aluminum sphere 58 centimeters in diameter (about twice the size of a basketball) with four long antennae deployed after separation. It would be only 100 kilograms at most, compared to the over 1,000 kilograms of Object D. The final weight of Object PS was 83.6 kilograms. Instead of carrying hundreds of kilograms of scientific equipment, it would only have a few kilograms of radio transmitters. Basically, its only mission was to beep.

Two military R7 rockets were assigned to launch the Simplest Satellite and a successor. But, before the R7 could launch a satellite, it needed to prove that it could perform its primary mission: delivering warheads. The R7 needed to complete two successful test flights before going to space.

A total of five tests using inert nosecones – not live warheads – were conducted in Kazakhstan at a brand new launch site: the Baikonur Cosmodrome.

The first three R7 launches failed for various reasons, but the fourth and fifth were successful. Well, except for the dummy warhead that burnt up on the fifth launch, but that wasn’t the rocket’s fault. Those successful test flights cleared the way for the first orbital launch attempt.

The R7 rocket with Sputnik 1 launched at 19:28:34 UTC on October 4, 1957. After 295 seconds of burn, the 1.5-stage rocket inserted Sputnik 1 into a 223-by-500-kilometer orbit inclined 65 degrees to the equator.

TASS, the state news agency, did not announce the successful launch until the satellite had completed an orbit to ensure it was transmitting successfully.

IMAGE: Vanguard 1. Dented metallic sphere in two halves with 5 attached bent and damaged rod antennae. Surface of sphere has square windows protruding with dark material and broken glass. CREDIT: National Air and Space Museum

Sputnik 1’s radio transmitter functioned for three weeks, delighting amateur radio operators around the world. The two frequencies it transmitted on were disclosed by the Soviets before launch. It re-entered the atmosphere after three months in January 1958.

The launch took the U.S. by surprise, even though the Soviets had announced plans for a satellite months and years prior to the launch. The Eisenhower administration considered it a stunt, only later taking it seriously. The launch of Sputnik 1 sent a wake-up call to the U.S.; it was proof that the Russians had the capability to nuke the United States with little notice. In reality, the R7 was a very poor tactical missile because it required hours of preparation on the launchpad to load its cryogenic liquid propellant.

The Sputnik Crisis, as it became known, caused an overhaul in the U.S. education system to focus on more math and science. The U.S. passed the National Defense Education Act a year after Sputnik’s launch to increase funding for education at every level and to encourage students to study science and technical fields. A specific curriculum change — that has persisted to this day — introduced hands-on laboratory experience.

The U.S. could have launched a satellite in September 1956 on a Jupiter-C rocket by Werner Von Braun’s team in the U.S. Army; however, because the U.S. wanted the first American satellite to be a civilian satellite and not a military satellite, the final stage was filled with sand instead of rocket fuel to ensure that a military satellite wasn’t “accidentally” launched first.

The civilian program produced the Vanguard rocket, which was developed from a sounding rocket called Viking. Vanguard made its first launch in March 1958 and failed spectacularly on live television. The tiny satellite, Vanguard 1, about 1.5 kilograms, was dubbed “Kaputnik” by the press. Despite its small size, the satellite survived the explosion only mildly dented and is now on display at the National Air and Space Museum.

More Information

Creation of the first artificial earth satellites (Buran)

Korolev and Freedom of Space: February 14, 1955–October 4, 1957 (NASA)

R7 (Astronautix via Internet Archive)

How Sputnik changed U.S. education (The Harvard Gazette)

Jupiter C Fact Sheet (


Leave a Reply

Got Podcast?

A community podcast.

URL * RSS * iTunes

Astronomy Cast LogoTake a facts-based journey.

URL * RSS * iTunes * YouTube

Daily Space LogoSpace & astronomy news.

URL * RSS * iTunes * YouTube

Join the Crew!

URL * RSS * iTunes * YouTube

Un podcast en español de cosmología y astronomía.
Premiering in October!

Become a Patron!
CosmoQuest and all its programs exist thanks the generous donations of people like you! Become a patron & help plan for the future while getting exclusive content.