Abandon Galaxy! is the second of two "Commander Craig Galactic Adventures" by "Bart Somers," one of the countless pseudonyms used by the prolific Gardner F. Fox.
Although published in the late Sixties, the "Commander Craig" books (the first tome is called Beyond The Black Enigma) harken back to 30's-styled space opera pulp, and are outrageously plotted. Great fun. I'm not certain who the cover artist is, but it's been suggested to me that it might be the work of Jack Gaughn.