The Outward Urge

Blurb

The Outward Urge is a science fiction novel by John Wyndham. It was originally published with four chapters in 1959. A fifth chapter was included in later versions, which was originally published in 1961 as a separate short story The Emptiness of Space.
The novel's stated authorship has a peculiar history. It was published as co-written by John Wyndham and Lucas Parkes, but they were different pen-names for the same writer. He had used the pen-name Lucas Parkes earlier in his career. Unlike most of his novels, The Outward Urge was conventional hard science fiction and his publishers decided that they wanted to use the Wyndham and Parkes byline because it was "not your usual Wyndham style".