Humans have always dreamed about reaching for the stars. In the second half of the 20th century, space exploration become a reality when scientists developed rockets that were powerful enough to overcome the force of gravity. On Oct. 4, 1957, Russians launched the first artificial satellite, Sputnik 1, into space. In 1961, Yuri Gagarin became the first human to orbit Earth. His flight lasted 108 minutes, and Gagarin reached an altitude of 327 kilometers.
The first U.S. satellite, Explorer 1, went into orbit on Jan. 31, 1958. In 1961, Alan Shepard became the first American to fly into space. Landing a man on the moon and returning him safely to Earth within a decade was a national goal set by President John F. Kennedy in 1961. During the 1960s, unmanned spacecraft photographed and probed the moon before astronauts were sent there. On July 20, 1969, Apollo 11 landed on the moon and astronaut Neil Armstrong famously described this achievement as ‘a giant leap for mankind’.
By the early 1970s, navigation satellites were in everyday use, and the Mariner spacecraft was orbiting and mapping the surface of Mars. By the end of the decade, the Voyager spacecraft had sent back detailed images of Jupiter and Saturn, their rings, and their moons. Skylab was America’s first space station. In the 1980s, satellite communications expanded to carry television programs and people were able to pick up the satellite signals on their home dish antennas. Sally Ride became the first American woman to go into space when she flew on the space shuttle Challenger on June 18, 1983.
As space exploration continued, twenty-four successful shuttle launches took place, until January 28,1986, when just 73 seconds after liftoff, the space shuttle Challenger exploded. The crew of seven was killed. The Columbia disaster was the second shuttle tragedy. On Feb. 1, 2003, the shuttle broke apart while reentering the Earth’s atmosphere, killing all seven crew members.
The tragedies made it clear, what kind of dangers were involved in human attempts to reach for the stars. However, they did not prevent scientists and governments from continuing their efforts. Mars is focal point of modern space exploration, and manned Mars exploration is a long-term goal of the United States. NASA is on a journey to Mars, with a goal of sending humans to the Red Planet in the 2030s. NASA and its partners have sent orbiters, landers, and rovers, increasing our knowledge about the planet. The Curiosity Rover has gathered radiation data to protect astronauts, and the MARS 2020 Rover will study the availability of oxygen and other Martian resources.