The Rolling Stones

When the Stone twins made up their minds to leave Lunar City in a secondhand spaceship they hadnt planned on having their whole family accompany them. But the Stones were not your ordinary Lunar family -- no way! -- and their voyage through the solar system sure proved it. What began as a simple business expedition to Mars soon mushroomed into a dangerous situation when Grandma Stone was lost in space. Then just when everything seemed to be getting better a Martian flatcat came aboard and fouled up the works. But the real trouble didnt get underway until the Stones headed for the asteroid belt to take up a mining proposition they somehow couldnt refuse . . .