Apollo 15 Postage Stamp Incident

The crew of Apollo 15 took 398 commemorative postage stamp covers with them on their trip to the Moon (400 were printed, but two were damaged and destroyed prior to being packaged), with the understanding that, when they returned, 100 of the covers were to be sold to the German stamp dealer who provided them. Those 100 covers are known today by philatelists as the "Sieger covers", named such after the dealer, Hermann Sieger. The remaining 298 covers were to be kept by the crew members as souvenirs but were later confiscated by NASA when the public sale of Sieger's covers was discovered soon after the mission. The crew's 298 covers were not returned until 1983, after the astronauts filed suit against the government for their return, citing NASA's partnership with the U.S. Postal Service to sell covers flown on the Space Shuttle.

Although taking souvenirs into space was not illegal nor prohibited by NASA at the time—the Apollo 15 crew had 243 authorized covers on board in addition to the 398 unauthorized covers—the discovery of the Sieger covers' sale caused Congress to take notice and led to NASA taking disciplinary action against several Apollo astronauts, including Apollo 15 commander David Scott, who admitted to carrying the stamps, and Jack Swigert, who was not involved in the incident directly but was less than forthcoming when asked to provide information to investigators about the practice of carrying souvenirs aboard spacecraft. Scott was already working on the docking system for the upcoming Apollo-Soyuz Test Project. Apollo 15 crewmember Alfred Worden was reassigned to a non-flight role within NASA and crewmember James Irwin resigned to pursue a Christian ministry in Colorado Springs, Colorado. Congressional questioning of NASA officials over the affair was a further source of embarrassment for the agency.

Al Worden recounted his participation in the "flown covers" controversy in his 2011 autobiography: Falling to Earth: An Apollo 15 Astronaut’s Journey to the Moon; he also detailed how this incident forced him out of the astronaut program, and how he later successfully sued the U.S. government in retrieving the covers after they had been surrendered pending a congressional investigation.

The market value of these postal covers has climbed steadily over the years, given their rarity and broad appeal to both space and stamp collectors. An example sold at the January 2008 Novaspace auction for US$15,000.