Glow sticks glow when hydrogen peroxide mixes with phenyl oxalate ester and a fluorescent dye.
This orange glow stick is from the supply that the closeout crew uses to tuck into the upper arm shoulder pockets of astronaut crew members before they board the orbiter. Like the color of the Advanced Crew Escape Suits (ACES), the glow sticks are intended to give the astronauts a means of signaling rescuers in the event of an emergency landing in darkness.
