I read this novel back on deployment 5 years ago. The cover was red with a polaroid photo of a green army man toy holding what appears to be a flamethrower and he is in background of grass.
A team of soldiers and scientists get stranded on a planet and one of the scientists is the main character. They are their to terraform the planet but end up getting stranded. You come to find out later that the scientist is actually a lot older than he appears, he has been able to transfer his consciousness and has been alive for a very long time. He is also hunted by a friend in the past that wants to take everything he loves. Main character developers a relationship with one of the female soldiers.