[johndallman]

Cosmos 1999 is the French title of Space: 1999.

The distance and speeds in the source series don't make any sense. The Moon is supposedly travelling at speeds that let them have an encounter with an Earthlike solar system every few months for the characters, implying hundreds of times the speed of light. Nonetheless, the Eagle shuttles, built for use on the Moon, are apparently able to slow down, land on bodies in those systems, and then catch up with the Moon, without any sense of time pressure.

Spaceships is far too hard-science for a campaign in this setting. Don't try to use it, you'll just be making life hard for yourself.