NASA’s Jet Propulsion Laboratory is turning 90 this year, and to celebrate, it’s doing something truly generous: letting the public visit its campus at the base of the San Gabriel Mountains in Southern California. The open-house event, called Explore JPL, runs Oct. 10 and 11 from 9:30 a.m. to 4 p.m. PDT, and promises to let visitors poke around iconic facilities and themed areas like “Missions That Changed the World,” “Moon to Mars,” “In Flight,” and “Makerspace.”

Tickets are free, which is nice, but they’re also “very limited” and historically vanish faster than a Mars rover’s signal during a dust storm. They go live on the Explore JPL webpage at 9 a.m. PDT Sunday, Aug. 29, on a first-come, first-served basis, with a maximum of five per requestor. Order more than five, and JPL may cancel your whole lot - so no, you can’t outfit your entire neighborhood. Tickets are assigned to specific time slots and named individuals, so don’t plan on sneaking in before your designated hour.

JPL, a division of Caltech in Pasadena, started as a rocket-propulsion project in 1936. By 1958, it had built and helped launch America’s first satellite, Explorer 1 - the same year Congress created NASA, which promptly adopted JPL. Since then, the lab has managed such hits as Voyager, Galileo, Cassini, the Mars Exploration Rover program, the Perseverance Mars rover, Europa Clipper, and many more. Basically, if it’s gone to another planet, JPL probably had a hand in it.

Attendees must bring their tickets and, if 18 or over, government-issued ID. Tickets are non-transferable and cannot be sold. Children under 2 don’t need tickets, though the event isn’t really designed for toddlers who might confuse a Mars rover with a shiny toy. Prohibited items include weapons, explosives, incendiary devices, glass containers, alcohol, cannabis, illegal drugs, pets (except certified service animals), banners, signs, flags, boom boxes, air horns, musical instruments, and professional camera equipment with detachable telephoto lenses. Laser pointers and whistles are also banned. No bags, backpacks, or hard-sided coolers are allowed - only small purses and diaper bags. Drones are forbidden from flying over JPL under any circumstances. Skates, skateboards, scooters, Segways, and bicycles are not permitted inside the event, because pedestrians are apparently a thing. Vehicles entering JPL property are subject to inspection. Parking is free, which is probably the best news you’ll get all day.

Voyager 1 and its twin Voyager 2 are the only spacecraft ever to operate outside the heliosphere, the protective bubble… NASA’s Mars Perseverance rover seeks signs of ancient life and collects samples of rock and regolith for possible Earth return.