Space Warrior Baldios (1980)

The series starts in the futuristic world of S-1. Long-term environmental damage due to warfare has forced the survivors to live underground. A the team of scientists finds a way to restore the planet's ecosystem. But at that point the militant leader Zeo Gattler stages a bloody coup d'état. The planet's emperor is assassinated. The head scientist's laboratory is destroyed along with its staff and their research. Gattler loads the entire civilian population into a space fortress which then leaves the planet. They are searching for a new planet to conquer. Marin Reigan, the head scientist's son, is caught in the fortress' warp drive and time travels to Earth in the year 2100. He has to defend the planet against Gattler's invasion force.