Mutant youth return to Earth

This was a novel from late 80s or early 90s. Type of story where space-faring humans return to explore damaged Earth. I don’t remember if they were trying to revive the Earth, ran into hostile survivors, or just dealt with harsh conditions.

But in this case the crew of young adults are mutants (maybe from space radiation in their habitats) and have exotic appearances. One guy was tall and rock-like. They might have had psionic powers. So like The 100, but with mutants.