Before the mid-20th century, most people felt travelling into space was an impossible dream. However, some scientists were d    1     to help humans realise their dream to explore space. After many experiments, they succeeded in making r    2    that could escape Earth’s gravity. On 4 October 1957, the Sputnik 1 satellite was l    3    by the USSR and successfully orbited around Earth. Afterwards, the USSR focused on sending people into space, and on 12 April 1961, Yuri Gagarin became the f    4    person in the world to go into space. Over eight years later, on 20 July1969, American astronaut Neil Armstrong stepped onto the moon, famously s    5    , “That’s one small step for [a] man, one giant leap for m    6    .” Following this, many more goals were achieved. For example, America’s NASA space-agency launched Voyager 1 on 5 September 1977 to study deep space, and it still t    7    data today.

Although scientists try to make sure nothing goes wrong, accidents can still happen. All the astronauts on the USSR’s Soyuz 11 and America’s Challenge died during their missions. These disasters made everyone sad and disappointed, but the desire to explore the universe never died. This is because people believe in the importance of c    8    on space exploration d    9     the huge risks. An example of this ongoing work is the International Space Station. It orbits Earth and has astronauts from different countries on b    10    , providing a continuous human presence in space.