The Principal Investigator (PI) in-a-Box knowledge-based system (KBS) helps astronauts perform science experiments in space. These experiments are typically costly to devise and build, and often difficult to perform. Further, the space laboratory environment is unique, ever-changing, hectic, and therefore stressful. The environment requires quick, correct reactions to events over a wide range of experiments and disciplines, including ones distant from an astronaut’s main science specialty. This suggests the use of advanced techniques for data collection, analysis, and decision-making to maximize the value of the research performed. PI-in-a-Box aids astronauts with "quick look" data collection, reduction and analysis, and also with equipment diagnosis and troubleshooting, procedural reminders, and suggestions for high-value departures from the pre-planned experiment protocol. The astronauts have direct access to the system, which is hosted on a portable computer in the Spacelab module. The system is in use on the ground for mission training, and has been delivered to NASA for in-flight use on the Space Life Sciences (SLS) 2 Shuttle mission scheduled for August, 1993.