Apollo 15 postal covers incident in the moon landings, the public's fascination with items flown in space increased, as did their value. Although it was not publicly known until September 1972, 15 of the men who entered space as Apollo Program astronauts, before Apollo 15, had agreed with a West German named Horst Eiermann to autograph 500 philatelic items (postcards and blocks of stamps) in exchange for $2,500. This included a member of each mission between Apollo 7 (1968) and Apollo 13 (1970). These items were not taken into space. Covers were prepared by the crews and flown on Apollo 11, Apollo 13 and Apollo
Apollo program mated to their launch vehicles. The Apollo spacecraft could be tested in two vacuum chambers capable of simulating atmospheric pressure at altitudes up to , which is nearly a vacuum. Administrator Webb realized that in order to keep Apollo costs under control, he had to develop greater project management skills in his organization, so he recruited Dr. George E. Mueller for a high management job. Mueller accepted, on the condition that he have a say in NASA reorganization necessary to effectively administer Apollo. Webb then worked with Associate Administrator (later Deputy Administrator) Seamans to reorganize the Office of Manned Space