Sci/Fi series with aliens, spaceships, mercenaries, "Lucky," and a robot android

[Sarge54963]

There is a book series that I started reading a few years ago. I can’t remember the title or the author.
The book was based on a veteran human (possibly named Jason) who finds his way onto a spaceship on earth and ends up becoming the leader of a group of outcast mercenaries that do their best to help people.
it is set in a modern earth that does not know about other species or other worlds.
I know there is a robot android that the main character names lucky. There are a few others but I can’t remember any names.
Any help would be great. Thanks!

 

[Orcadian]

Don't know this book, I'm afraid, but this link might be helpful? List of fictional robots and androids - Wikipedia