14 CFR 1214.604 - Personal Preference Kit (PPK).
(a) Purpose. The PPK enables persons accompanying Space Shuttle flights to carry personal items for use as mementos. Only those individuals actually accompanying such flights (astronaut crew members, payload specialists, and space flight participants) may request authorization to carry personal items as mementos. These items must be carried in individually assigned PPK's.
(b) Limitations. The contents of a PPK must be limited to 20 separate items, with a total weight of 0.682 kilograms (1.5 pounds). Each item is allocated for a different recipient and distributed accordingly. The volume of a PPK must be contained in a 12.82 centimeters × 20.51 centimeters × 5.13 centimeters (5″×8″×2″) bag provided by NASA. Increases in these limitations will be authorized only by the Associate Administrator for Space Flight.
(c) Approval of Contents. At least 60 days before the scheduled launch of a Space Shuttle flight, each person assigned to the flight who desires to carry items in a PPK must submit a proposed list of items and their recipients to the Associate Director, Johnson Space Center. The Associate Director will review the requests for compliance with this subpart and submit the crew members' PPK lists through supervisory channels to the Associate Administrator for Space Flight for approval. A signed copy of the Associate Administrator for Space Flight's approval will be returned to the Director, Johnson Space Center, for appropriate distribution.