Jay Manifold has a sobering coda to my Wrightathon.

On this anniversary, half a million people will be in the air in this country alone at any given moment.

For comparison, on the fortieth anniversary (12 April 2001) of the first manned space flight — a period of breakneck technological and economic advances — there were exactly three human beings in space, the Expedition Two crew of Usachyov, Voss and Helms aboard the International Space Station.