This is book 1 of the "Subspace" series.

This note contains spoilers for the book.

From the July 1960 edition of Astouding Science Fact and Fiction magazine, this later formed the first part of Subspace Explorers (#7). I read it courtesy of Project Gutenberg.

There is considerably more to the story than to the version included in the novel. Bobby Warner does acrobatics in zero g to prove she could, for one thing, and is embarrassed when people think she's showing off (and approve of her doing so).