Top 10 Greatest Triumphs in Space Exploration

Script written by Sean Harris.

Some of the most amazing space exploration achievements have happened in recent memory. Whether it’s the Mars Exploration Rover or NASA’s New Horizons space probe doing a flyby of Pluto, these are important space travel successes – as are things like the Hubble Space Telescope and the start of the space shuttle era. WatchMojo counts down ten of the greatest moments in space exploration history.

Special thanks to our users Mancannon55K, jackhammer and Cameron Halas for suggesting this idea! Check out the voting page at WatchMojo.comsuggest/Top%20Ten%20Space%20Exploration%20Achievements


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Script written by Sean Harris.

Top 10 Greatest Triumphs in Space Exploration

The Universe is a very big place, and these are the best efforts humankind has made to explore it so far. Welcome to and today we’re counting down our picks for the top 10 space exploration achievements!

For this list, we’re looking at the greatest achievements in the history of space travel and the moments that have most advanced scientific research and our understanding of space to date.

#10: Sputnik 1
October 4, 1957

The successful launch of Sputnik 1 by the Soviet Union was the first major move in the twentieth century space race between the USSR and the USA. As the first artificial Earth satellite, the now-iconic spherical design of Sputnik 1 caught global attention as a Soviet-made ‘star’ in the sky. It was a symbol of hope and scientific endeavor for many, but it also prompted Cold War concerns in America. The 184-lb spacecraft orbited Earth once every hour and 36 minutes, travelling at 18,000 mph, for 92 days. When it eventually burned up re-entering Earth’s atmosphere on January 4th 1958, it had travelled more than 40 million miles.

#9: The First Space Station
April 19, 1971

After America’s history-making Apollo 11 mission, the Soviet Union changed direction with its space program and focused on the creation of the first space station. Salyut 1 was launched in April 1971, more than two years before USA could launch their own SkyLab program. An unforeseen design issue meant that the first mission sending cosmonauts to the station was aborted, but success came on the second attempt with the 3-man Soyuz 11 crew able to complete docking and stay on Salyut for 23 days. The mission ended in tragedy however, when a faulty valve led to the depressurization of the Soyuz capsule upon re-entry into the Earth’s atmosphere, killing all three crewmen.

#8: New Horizons’ Flyby of Pluto
July 14, 2015

NASA’s New Horizons space probe has certainly lived up to its name. As the first mission launched in the New Frontiers program, in July 2015 it became the first ever spacecraft to flyby Pluto, getting as close as 7,750 miles and collecting never before seen images and data. Pluto was always the primary target for the mission, but New Horizons’ journey to the outer edges of our Solar System has seen other major successes as well. In 2006 alone it passed the orbit of Mars, tracked a small asteroid for two days and photographed Jupiter. And the journey didn’t stop at Pluto; during the summer of 2016, NASA announced plans to extend the mission into the Kuiper Belt.

#7: The Start of the Space Shuttle Era
April 12, 1981

For 30 years, the Space Shuttle program was America’s ticket to the stars. The five shuttle fleet of Columbia, Challenger, Discovery, Atlantis and Endeavour flew a combined 135 missions, beginning with Columbia’s inaugural launch in April 1981. As the first reusable spaceship, the shuttles of the Space Transportation System flew over 542 million miles, made over 21,000 Earth orbits and carried over 350 people into space. They played a role in building the International Space Station and the triumph of the Hubble Telescope. The vast majority of shuttle missions were a success, but there were two tragic events: a combined 14 astronauts were killed during the Challenger and Columbia disasters. When the Atlantis landed for the last time in July 2011, it was the end of an era.

#6: The Voyager Programs
August 20, 1977 & September 5, 1977

The Voyager program started with two crafts built to last five years, sent to explore Jupiter and Saturn. Today, roughly four decades since launch, Voyager 1 and 2 are still out in space, exploring more of the great unknown than anything has ever done before. The probes have visited all of the outer planets of our Solar System plus 48 moons, and both are now far beyond Pluto. Voyager 1 created history when it entered interstellar space in August 2012, and it’s now hurtling to the outermost edges of the Sun’s influence. The probes are even prepared for the eventuality that they come into contact with alien lifeforms – both contain images and audio - via the Voyager Golden Records - showing life and culture on Earth.

#5: The Hubble Space Telescope
April 24, 1990

When the space shuttle Discovery set the Hubble Telescope into orbit around the Earth, it initiated perhaps the most significant advance in astronomy since Galileo crafted his telescope in the early 1600s. Since its 1990 launch, Hubble has journeyed more than 3 billion miles and taken more than 1.2 million observations. Data collected from the HST has helped refine estimates on the age of our universe – to around 13.7 billion years old. It has also been used to further our knowledge of black holes and broaden our understanding of how big the universe actually is. In March 2016, Hubble was used for the discovery of GN-z11, the farthest known galaxy to humankind – so far.

#4: The Mars Exploration Rover
June 10, 2003 & July 7, 2003

Since their 2003 launch, the twin rovers Spirit and Opportunity have exceeded their targets for the Red Planet, and have spearheaded NASA’s twenty-first century Mars ambitions. The rovers are designed to analyze soil and rock samples to determine whether there is, was or ever could be life on Mars. Although contact with Spirit was lost in 2010 and its mission ended in 2011, both rovers have also exceeded their planned mission times. Opportunity continues to explore a planet it now shares with 2012’s Curiosity rover. The images and data sent back by Opportunity have proven vital in humankind’s quest to learn more about Martian history, and have further boosted future hopes for manned missions to visit our neighbor.

#3: First Man in Space
April 12, 1961

Having already earned a lead in the space race with Sputnik 1, the Soviet Union further stretched the boundaries of human possibility in 1961, when Yuri Gagarin became the first man in space. America had been striving to launch an astronaut of its own, but was narrowly beaten by its rival once again. Gagarin took to the skies in Vostok 1 and circled Earth once during a flight that lasted 108 minutes. He became a national hero and the most talked about person on the planet. A global tour followed, as crowds gathered to catch a glimpse of him. The cosmonaut proved quite the public speaker too, and was said to have a smile that “lit up the Cold War.” Two years later, Valentina Tereshkova would be the first woman to fly in space via the Volstok 6.

#2: First Space Walk
March 18, 1965

Having put the first ever satellite, man and woman into space, the Soviet Union is also responsible for the first ever spacewalk. Alexey Leonov left the Voskhod 2 spacecraft in March 1965 to float above our planet with only a 16 foot cord keeping him from certain death. While the mission was a success in the end, there were endless problems. During the walk, Leonov’s spacesuit inflated, causing massive difficulties when he tried to return to the ship. After the walk, a rise in oxygen levels meant Voskhod 2 became highly flammable. And problems during re-entry stranded Leonov and his partner, Pavel Belyayev, in Siberia. So, not only was the mission a feat of science, but it also proved a problem-solving masterclass.

Before we unveil our top pick, here are a few honorable mentions.
- Expedition 1 – First Long-Duration Stay of a Crew on the ISS
November 2, 2000

- SpaceShipOne – First Manned Private Spaceflight
June 21, 2004

- Alan Shepard – First American to Travel Into Space
May 5, 1961

#1: First Human on the Moon
July 20, 1969

NASA’s Apollo program made many a mark on the history of space travel. The Apollo 8 moon orbit might’ve made today’s top spot, but Apollo 11 is humankind’s most momentous moment in space. If Sputnik 1 started the space race, then Neil Armstrong, Buzz Aldrin and Michael Collins ended it on July 20th, 1969. Armstrong’s first steps onto the Lunar surface and his immortal words made for one of the most iconic moments in modern times. Aldrin and Armstrong collected soil and rock samples and planted the American flag, before leaving various mementos, including an Apollo 1 mission patch and a Soviet medal commemorating Yuri Gagarin. “One giant leap for mankind,” Apollo 11 still sets the benchmark for space exploration.

Do you agree with our list? Which galactic achievement most impresses you? For more out of this world top 10s published daily, be sure to subscribe to

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