A J Merak: 5 books

The Colony on Rigel IV had been founded seven hundred years earlier but for the past six centuries, they had been forced to exist on the bottoms of the great oceans of the planet, kept there by the tremendously potent weapons of the alien star-race which had swept down out of space and wiped them...

Earth was threatened with attach from the huge space-fleets of the Hundred Suns of Andromeda - an attack that the Terran Fleet could not hope to defeat. Only one chance remained to prevent Earth's destruction, and that was the chance that a skilled and experienced saboteur might just have time...

All the known planets had been conquered and colonized. Pluto was the last - as far as man could go into space. Beyond the frozen planet lay an immeasurable gulf of light years which no man could cross in a single lifetime. But one man kept trying to find the answer.

Planet Earth was finished, its surface seared by nuclear heat, its great cities obliterated, its billions of inhabitants dying or dead. Only a few pockets of survivors remained. For all but a few it was only a matter of time. Then into the poisoned atmosphere of Earth there flashed a mysterious craft...

The logical outcome of the space race, and the preliminary step towards the Moo, was the manned satellite, the Big Wheel moving in a stable orbit about the Earth, integrating the data necessary for a landing on the Moon, and eventually acting as a fuelling station for the Lunar rockets. After...