Attention, space enthusiasts! Although NASA isn't going to take anybody to Mars any time soon, you can send your name to Mars, and collect frequent flyer points. I tried it out and now have 297,805,305 miles, though they are for the InSight mission which hasn't gone anywhere yet.
It's easy to do - all ages can participate. But the deadline for registration is September 8, 2015 (11:59 p.m. ET). Over 440,000 people have signed up so far. Here's the link:
Mars Frequent Flyer Club Geeks and kids might enjoy it.