PPK
Original archive entry. The text, images and links below are kept as they were written.
Personal Preference Kit. NASA astronauts were limited to taking a Personal Preference Kit (PPK) of no more than twenty items and 700 g mass on a spaceflight. These had to be submitted to NASA for approval weeks before the flight and were locked in a mid-deck shuttle locker. Collectibles such as rolls of coins, stamps, pins, flags, and so on were prohibited to prevent the astronauts from profiting personally from the flight.