Space Race: Sputnik, Gagarin, Apollo 11 and the ISS

The rocket equation

A rocket stands on the pad, and a line shows its exhaust streaming down. In 1903 the Russian teacher Konstantin Tsiolkovsky published the equation that governs every rocket: the gain in speed equals the exhaust speed times the natural logarithm of the starting mass divided by the final mass, or Δv = vₑ · ln(m₀/m₁). Most of a rocket is fuel, and the more it burns, the less each extra kilogram adds. That is why real rockets drop empty stages. Reaching low orbit needs a speed of about 7.8 kilometres per second, and with drag and gravity losses the rocket must gain about 9.4. The equation is maths, tested by every launch.

A beep from orbit

A bright dot circles Earth, and a thin signal beeps. On 4 October 1957 the Soviet Union launched Sputnik 1, the first artificial satellite: a polished sphere 58 centimetres wide, weighing about 84 kilograms, that went round Earth in roughly 96 minutes. Radio amateurs everywhere tuned in to its beeps. In the Cold War rivalry between the USSR and the United States, the launch caused alarm in America, which created NASA in 1958 and invested in science teaching. The flight showed that a rocket developed as a missile could also lift a satellite, and the same technology served both purposes.

The first human in orbit

A tiny capsule loops round a blue globe. On 12 April 1961 Yuri Gagarin, a 27-year-old Soviet pilot, launched aboard Vostok 1 and made a single orbit lasting 108 minutes. He ejected from the capsule at about seven kilometres’ height, as planned, and landed by parachute. On 5 May Alan Shepard became the first American in space, on a short flight that did not reach orbit. We know the details from flight records and later Soviet disclosures. Gagarin’s flight proved that a person could survive weightlessness, and the race to go farther began.

To the Moon

A tower taller than a skyscraper begins to rise on a column of fire. The Saturn V, about 110 metres tall, was the most powerful rocket of its day. Apollo 11 left Florida on 16 July 1969 with Neil Armstrong, Buzz Aldrin and Michael Collins. The effort was driven by President Kennedy’s 1961 goal of landing a person on the Moon within the decade, and by Cold War rivalry. About 400,000 people worked on the programme. The Soviet N1 rocket, built for the same goal, failed in all four of its launch attempts.

One small step

Two figures in white suits move slowly over grey dust under a black sky. On 20 July 1969 the lunar module Eagle landed in the Sea of Tranquility, and Armstrong and Aldrin walked on the Moon for about two and a half hours while Collins orbited above in Columbia. They planted a flag, set up experiments and gathered about 21 kilograms of rock and soil. An estimated 600 million people watched on television. The crew splashed down safely on 24 July. Moon rocks still help scientists study the early Solar System, and observers in other countries tracked the mission.

Living in orbit

A long frame of white panels glides over the night side of Earth. The International Space Station, built by space agencies from the United States, Russia, Europe, Japan and Canada, has had people aboard continuously since November 2000. It circles Earth about every 90 minutes at roughly 400 kilometres up, and it works as a laboratory for medicine, materials and the study of long stays in weightlessness. Meanwhile robots explore other worlds. Rovers have rolled over Mars since Sojourner in 1997, followed by Spirit, Opportunity, Curiosity and Perseverance, searching for signs that water once made the planet habitable. The next chapter of this story is still being written.

The Space Race