Well, Jon got me off on a tangent again. Worked up the Viking Lander (Orbiter still in progress) to fill a request for a school project. I can't very well refuse, as that is my excuse - sorry, reason - for enjoying this hobby.
Did Math 'til mid-night for a class of fifth graders yesterday - Viking Lander prototype has a home, as do the Soyuz "Kinder-Rockets" we constructed (available at Lower Hudson Valley Challenger Center for download). I had them work in teams to speed things up - one page per student. We rolled cylinders and cones, scored, cut and folded, and taped and glued. Seemed to work out - note for future: it takes a full hour to get the rocket built, even working in teams of two; take more round-things to roll cylinders with and get them a tiny bit undersize (little hands don't roll paper very tightly).
Since the topic was math and not just Aero-gami; we passed around the Earth and talked about the relative sizes of the Moon and Mars - double the "size" and you get four times the area and eight times the volume/mass.
Next time (they and the teacher/parents seemed happy so there might be a next time) we build little gliders!