This a collection of three short novels by Edmond Hamilton. It's pure adventure scifi, little merit in creativity, but man is it engaging reading. It's clear why this stuff sells. The physical writing is horrible, absolutely horrible, bad grammar, lots of excess words. Often I put the page down for a second I'm so annoyed. However, the characters are riveting, and you never know how the space mercenaries are going to get out of their current mess. If you want a plot structure for pulp scifi adventure stories, this book is perfect. It knows where to start and where to end.
I believe it's currently out of print though. I got this book from my brother, so it might be hard to find.