Forever free
From back cover Ace paperback November 2000:

A veteran of The Forever War, William Mandella lives on the snow-covered planet set aside for his kind, supporting his family by ice-fishing and teaching physics.  But now Mandella's life has become obsolete.

The denizens of Earth have evolved into a group consciousness and taken control of his new home -- keeping its independent human inhabitants alive for the sake of their diverse gene pool.  But that's not how Mandella and his fellow soldiers want to exist.  So, in desperation, he rallies the humans to hijack a spaceship and take to the stars, to begin humanity anew...

Then something goes wrong.  The crew is forced to abandon ship -- and return home in suspended animation twenty-five years later.  But the planet has aged centuries during their voyage -- and the crew wonders what new world awaits their arrival...
Time travel, Fiction, Fiction, science fiction, hard science fiction, Mandella, william (fictitious character), fiction, Fiction, war & military
Joe Haldeman, Andre Martin Kostner
Joe William Haldeman (born June 9, 1943) is an American science fiction author. He is best known for his novel The Forever War (1974). That novel and other works, including The Hemingway Hoax (1991) and Forever Peace (1997), have won science fiction awards, including the Hugo Award and Nebula Award. He was awarded the SFWA Grand Master for career achievements. In 2012 he was inducted as a member of the Science Fiction Hall of Fame. Many of Haldeman's works, including his debut novel War Year and his second novel The Forever War, were inspired by his experiences in the Vietnam War. Wounded in combat, he struggled to adjust to civilian life after returning home. From 1983–2014, he was a professor teaching writing at the Massachusetts Institute of Technology (MIT).