Green Hills And Flying Mountains

Robert Heinlein's Future History, Volume II, The Green Hills Of Earth, is mainly about people living on the Moon although there is also information about Mars, Venus and life back on Earth. Interstellar travel does not begin until Volume IV.

Poul Anderson's Tales Of The Flying Mountains is a single-volume future history about people living on terraformed asteroids thanks to gyrogravitics, a technology not possessed by Heinlein's characters - who do gain control of gravity in one story set on Earth although this technology is not mentioned subsequently and later interstellar craft are spun to simulate gravity. A technology lost during the Interregnum of Volume III?

Interstellar travel has begun at the beginning of Tales Of The Flying Mountains. Indeed, it is the travellers themselves who review their asteroidal history for their own benefit and, of course, for ours.

There, if you want it, is a partial comparison between Heinlein's Future History and one of Anderson's eight future histories before I turn in for the night, looking forward to a morning of gardening. Good night.