Most of us are well aware of the Apollo 11 spacecraft for its famous ‘Lunar Landing’ – but how much do you know about the historical journey of space missions?

While Neil Armstrong will forever be remembered as the first man on the moon, did you know that more than 500 people have been to space to date? Have you heard about Albert the monkey and a dog named Laika, who experienced the thrill of space travel long before we could think about space tourism?  

Elon Musk’s SpaceX might make multi-planetary living a reality in the not-so-distant future. But if we are ever able to dine out at a pizza outlet on Mars someday (he’s promised it!), we definitely owe credit to the earliest scientists, astronomers, and astronauts who led the way in space exploration.

So, come, let’s travel back in time and take a look at some of the most important missions in the history of space travel.

Sputnik I

Sputnik I, also known as the Elementary Satellite I, holds the title for being the first man-made object to enter space. It was a 23-inch wide aluminum-based polished sphere with four external antennas for radio broadcast. This artificial Earth satellite was launched into space by the Soviet Union on October 4, 1957 (artificial satellite is the term used for all man-made satellites to distinguish them from natural satellites such as the moon).

The launch of this spacecraft was certainly what marked the beginning of the Space Age.

Sputnik I orbited the earth 1,440 times during a total of 21 days before it lost its signal due to weak batteries. However, it remained in orbit for almost two more months until it fell back into the earth’s atmosphere on January 4, 1958. Although the satellite burned upon reentering our atmosphere, it triggered the start of the Space Race as public fear and anxiety rose in America due to the perceived technological gap between the two countries in the midst of the Cold War era.

Sputnik II

Sputnik II was the second Soviet satellite launched shortly after the success of Sputnik I. It entered the orbit on November 3, 1957, carrying the first living being – a dog named Laika – into outer space. Unfortunately, Laika died within hours after the launch when the central sustainer failed to separate from the payload, causing her chamber to overheat.

This 13 feet high, cone-shaped satellite featured several high-powered radio transmitters that sent biological and space data such as the intensity of solar radiations back to earth. It was also equipped with a camera that provided live images of the dog as it zapped into outer space.

Explorer I

This mission officially marked the start of the Space Race as it was the first satellite launched by the U.S.

Explorer I entered the orbit on January 31, 1958, and collected valuable space data for almost four months before its batteries died. However, the satellite remained in orbit for more than 12 years, completing over 58,000 orbits as opposed to the Sputnik I that burned up after 1,440 revolutions only. This missile-shaped spacecraft was followed by the launch of over 90 more as part of the long-running Explorer series.

The note-worthy achievement of the Explorer I mission was that it helped scientists detect the Van Ellen radiation belt using the special cosmic ray detector housed in the spacecraft.

Explorer 6

Explorer 6, also known as S-2, was an unmanned satellite launched by the U.S. in August 1959. It was a small spherical spacecraft surrounded by four large solar panels designed to gain insight into the scientific mysteries lurking in space.

The Explorer 6 satellite allowed scientists to study geomagnetism, galactic cosmic rays, and the propagation of radio waves in the upper atmosphere of the earth. But what this satellite is really famous for is capturing the first picture of our beloved planet as viewed from outer space. The picture was taken from almost 17,000 miles above Mexico – though it was anything but the blue-green ball that we see today. Rather, it was more like a distorted stroke of white paint over a black background, which actually denoted cloud cover over a sunlit area in the Central Pacific Ocean.

The information collected through the success of this space mission played an important role in the mission to the moon.

Pioneer 5

Important Space Missions

Pioneer 5, nick-named the Paddle-Wheel satellite, was designed to study the interplanetary space between the Earth and Venus. It went into space in March 1960 and transmitted data for 50 days before the signals were lost. Scientists maintained contact for over 50 days more until it disappeared in the outer world.

This spacecraft investigated the solar flare particles and revolutionized space communication via its digital telemetry system, called Telebit.


Mercury-Redstone 2, commonly abbreviated to MR-2, was a space booster vehicle in NASA’s Project Mercury. With a chimpanzee named Ham on board, it took the penultimate flight before America’s first manned space mission.

The MR-2 propelled into space in January 1961 from the Cape Canaveral Space Wing in Florida. The flight took less than 17 minutes before landing into the Atlantic Ocean. Ham, hence, became the first animal to successfully complete a suborbital space journey.

Vostok I

Vostok I is one of the most important missions in space history because it was the first crewed spaceflight. It was part of the Russian Vostok Space Program that aimed to put Soviet citizens into low earth orbit and return them back safely.

The Vostok I capsule was launched on April 12, 1961, with a Soviet cosmonaut named Yuri Gagarin on board, thus, making him the first man to go into outer space. The flight took 108 minutes to reach the upper atmosphere and then travel back to earth. With 7 km to hit the earth’s surface, Gagarin ejected himself from the capsule and landed safely via a parachute as planned.

Prior to the execution of this space mission, the U.S.S.R. did a test flight with a dog and a human-size dummy on board a prototype of the Vostok I spacecraft.

Freedom 7

When we talk about the historical journey of space missions, this is a big one. This was U.S.A.’s first human-piloted space flight. Also known as MR-3, Freedom 7 was dispatched on May 5, 1961, with the same objectives as Russia’s Vostok I space mission.

It was a major breakthrough in space travel as the pilot, Alan Bartlett Shephard, tested the capsule’s technical systems and demonstrated humans’ ability to withstand the tremendously strong g-forces during launch and upon impact with the earth’s atmosphere during the return.

Other Prominent Events in the Historical Journey of Space Missions

The ISS Is An Important Achievement

March 7, 1962 – OSO-1, an orbiting solar observatory, was launched by NASA, allowing scientists to study the sun using the space telescope

April 26, 1962 – Ranger 4 became the first spacecraft to reach the moon. However, it crash-landed on the lunar surface without transmitting any useful data due to system failure

December 14, 1962 – Mariner 2 space probe successfully completed a flyby mission to Venus

June 16, 1963 – Soviet spaceship Vostok 6 carried the first woman to outer space

August 1966 – Lunar Orbiter 1, a robotic space probe not only orbited the moon but also photographed the lunar surface to determine safe landing sides for the upcoming Apollo missions

July 20, 1969 – Apollo 11 took the first man on the moon. In the words of the renowned astronaut, it was a ‘one small step for man; one giant leap for mankind’

April 24, 1990 – NASA deployed the Hubble Space Telescope that continues operating to date

November 20, 1998 – The International Space Station (ISS) was launched as a joint project by five participating space agencies from the U.S.A., Russia, Japan, Europe, and Canada. The ISS, about the size of a rugby field, is the largest satellite ever built and hence, the biggest man-made object orbiting in space

End Note

The historical journey of space missions shows the remarkable efforts that scientists have made for exploring the depths of the cosmos.  While most of these space missions quite literally took mankind way ahead of its time, others resulted in not-so-glorious events as spacecrafts were destroyed and lives lost against the sheer force of nature. Nonetheless, though we continue striving to travel to infinity and beyond, the contributions of every team involved in the earlier space missions will definitely be remembered forever.