Spaceward ho!

On 12 April 1961, the russian cosmonaut yuri gagarin (1934–1968) became the first human to leave the confines of Earth and ascend into space. Almost 480 individuals have followed him and, since 31 October 2000, humans have been in space without interruption. this is an enormous technological and scientific achievement; nevertheless, our species has only scratched the surface of what could be called space travel. So far, just 24 humans (during the US Apollo space programme that took astronauts to the Moon) have ever left direct low-Earth orbit (LEO)—that is, have gone further than approximately 500 km above the surface of the Earth. Despite these successes, it has not been shown yet whether and how humans can really travel and live in space. yet, why would we want to leave the Earth and where would we like to go? In fact, where can we go and what technologies do we need to get there? Here, I try to give some general answers to these questions, based on the present scientific and technological status quo, and on current or planned studies. nonetheless, the further we look into the future, the more speculative this article will inevitably become. In this regard, I can only offer my personal assessment of what might sound, at times, like science fiction.