One afternoon in 1936 CalTech grad student Alfred Malina recruited five friends to help out with some rocket experiments in the arroyo seco. The dry lakebed seemed like a safer place than the CalTech campus. These smart fellows would go on to form the Jet Propulsion Laboratory, America’s premiere spaceship factory. The space secrets are heavily guarded, but once a year the lab throws open its doors for a public open house. The free event starts Saturday at 9a.m. and includes tours of the clean rooms, space exhibits and Q&A’s with real live rocket scientists. Last year there was a chance for kids to lie on the ground and have the Mars rover drive over them. I wonder if the founders could have imagined such wonders 75 years ago?