Time to Travel Again in Space

It's been 225 years since the survivors of the extinction-level ice age that occurred on Earth-I have been brought to Earth-II. The six individuals who brought the survivors on Earth-II have been living on Earth-II with the descendants of the original settlers from the past twenty-five years. However, these six individuals are now becoming restless and want to go into space again. Even though they all are in their seventies, their life expectancies are such that they could live another fifty years. They increased the size of the spaceship they used to bring the survivors to Earth-II so they can increase the number of individuals who can travel with them. They leave Earth-II to revisit some of the planets they had visited previously as well as the edge of the known universe. They find life on several planets all of which has the same generic materials as humans. This book continues the adventure the space travelers have and the knowledge they obtain from traveling through space.