The Jet Propulsion Laboratory is holding its annual open house this Saturday and Sunday, starting at 9 am. If you are in the area, you can get in free. JPL is at 4800 Oak Grove Drive in Pasadena, California (the extreme Northwest corner of Pasadena). You will see displays and representatives from nearly two dozen missions into outer space, plus a number of special technology displays and exotic facilities, such as the Spacecraft Assembly Facility, the JPL 'Robo-Dome', and the Mars Rover test facility. Wear good hiking shoes and comfortable clothes. JPL is big.