PongSats are high-altitude "near-space" missions that hold a probe or other project that can fit inside a ping-pong (table tennis) ball.
JP Aerospace succeeded in its first launch of PongSat missions, with a balloon-launched rocket (AKA a rockoon), at the West Texas Spaceport near Fort Stockton, in October 2002.
[2] Although many PongSats contain things like food items, simply because schoolchildren are curious about the result, other missions include "multiple sensors and complex mini-computers".
[3] It's been described by its founder as part of "America's Other Space Program," but also as one that relies "primarily on volunteers and helium.
[5] According to founder John Powell, the PongSat launch program is very global, with payloads delivered to JP Aerospace from "Poland, India, Japan, Slovenia, Germany, Belgium, Turkey, China, Australia, Indonesia.