Mission of Gravity is a science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 novel

Novel

A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....

 by Hal Clement

Hal Clement

Harry Clement Stubbs better known by the pen name Hal Clement, was an American science fiction writer and a leader of the hard science fiction subgenre.-Biography:...

. The novel was serialized in Astounding Science Fiction magazine in April–July 1953. Its first hardcover book publication was in 1954, and it was first published as a paperback book in 1958. Along with the novel itself, many editions (and most recent editions) of the book also include "Whirligig World", an essay by Clement on creating the planet Mesklin

Mesklin

Mesklin is the name of a fictional supergiant planet created by Hal Clement and used in a number of his hard science fiction stories.It is distinctive for the interaction of its strong gravity with the centrifugal force due to its fast rotation, originating, according to Clement's original...

 that was first published in the June 1953 Astounding.

Clement published two sequels to Mission of Gravity, a 1970 novel called Star Light

Star Light

Star Light is a science fiction novel by Hal Clement. It is the sequel to one of Clement's earlier books, Mission of Gravity. The novel was serialized in four parts in Analog Science Fiction/Science Fact Magazine from June to September 1970...

, and a 1973 short story called "Lecture Demonstration".