These are plans for a playground piece called a Go Round.
This go-round puts kids in orbit! You don't need NASA to put your kids in orbit. They'll really get a blast out of this attachment that adds whiz-around variety to the back and forth motion of a set of swings. \
If your back yard is already graced with a sturdy swingset, you can add the whole pedal-plane unit at a cost of about $14 for materials.
The only power tools you'll need: an electric drill and an arc welder. Don't own the latter? Then you can prepare all pieces for assembly and take them to a welding shop.
If you have a backyard swing set, you can add this flyer to it and give it all the thrills of a big-time amusement park. No swing set? Then hang it from its own freestanding pole. Erect the pedal-plane as a separate unit, taking a bit more care with the "planting" of the pivot pole, and adding prop-type supports.
Either way, you'll be the hero of the local merry-go-round set.