Technical progress was very fast-pacing in the 20th century and lots of inventions were made, but some consider space exploration to be the greatest one, while others have a different opinion.
To my mind, space exploration really matters. Firstly, it allows us to gain more information about the Universe, other planets and stars. Secondly, a large number of other technologies take their way from space exploration. For example, GPS was firstly invented for this exact purpose. Finally, space exploration projects provide lots of workplaces.
Just imagine how many scientists and engineers work on the development of a new spaceship right now.
However, some people have an opposing opinion. They think that space exploration is not the most important achievement of the 20th century, saying that the Internet can be the greatest one.
Nevertheless, I cannot agree with the opponents. Of course, nowadays the Internet gives us many opportunities, but, anyway, it would not work without satellites floating in the space.
To sum up, though the 20th century became the era of technical progress, I strongly believe that space exploration is the most remarkable achievement of it.