What is the future for the space travel?
Taking a lift to the space stationspace travel
Forecasts are difficult to make,In 1960s,after the Apollo Moon flights,plans for a permanent,manned Moon base were already being made,and flights to the entire solar system seemed to be within the reach of astronauts.But then the Apollo program was cancelled,and for many decades manned space travel was limited to flights into Earth’s orbit. In the 1970s,many believed that the space shuttle ushered in the era of reusable spacecraft.
However,the shuttles have proved to be too complicated and too dangerous,and NASA is now returning to an approach that makes use of expendible rockets. Neverthless,if current plans are carried through,astronauts will return to the Moon by the end of the next decade, and if all goes well,the first manned flights to Mars may follow in about 20 years.
Who was the first human in space?
Four years after the ‘Sputnik shock’ of 1957,the USA had to accept another humiliating defeat in the space race. In April 1961,the Soviet Union sent the first human being into space abroad the Vostock 1 rocket. The cosmonaut Yuri Gagarin and his space capsule circumnavigated Earth only once, and after a flight lasting 1 hour and 48 minutes he landed safely back on Earth in southern Russia.The flight was entirely remote controlled and Gagarin would only have needed to intervene in the event of an emergency. It was’t until February 1962, after two successful sub-orbit flights , that the USA succeeded in sending their own astronaut John Glenn into orbit.
Why are the astronauts in space weightless?
Weightlessness does not mean that there is no gravity,only that the gravity is not perceptible.In fact,the gravity in an orbit close to Earth is not much less than it is on Earth’s surface. If we were able to construct a tower tall enough to reach that height, a person standing on the top of the tower would not be weightless.We feel our weight because the ground pushes up on us.,balancing the force of gravity. However, there is no ground for an astronaut floating in space,and so he or she does not feel the force. This is also true if the astronaut is in a satellite,since this doe