If you're spending your holiday weekend here on Earth, how about a couple of space books? (No, not space law books this time. Space fun.)
For you, Space Tourism - Adventures in Earth Orbit and Beyond, by Michel van Pelt (reviewed in Universe Today).
And for your kids, from Buzz Aldrin, who I hear was in my neck of the terrestrial woods yesterday (that's NYC, which, for a boy from New Jersey, must seem as alien as the moon), signing his new children's book, Reaching For The Moon.
Enjoy! (And whatever you do, don't plan your summer vacation using any unpredictable time machines.)