Twenty-Five-Foot Space Simulator

The Twenty-Five-Foot Space Simulator is a large testing chamber at the Jet Propulsion Laboratory in Pasadena that recreates the conditions of space. The facility contains a steel cylinder with aluminum components and a system designed to produce extreme cold, heat, and near-perfect vacuum.

The chamber was built in 1961 at JPL to test spacecraft before launch. It was designated a National Historic Landmark in 1985 for its importance to early American space missions.

The facility played a central role in preparing American spacecraft for their missions by simulating the harsh conditions they would face in space. Today, visitors can understand how engineers used this technology to push the boundaries of space exploration.

The chamber is part of the JPL campus and can be viewed from outside, though interior tours require special permission. Visitors should inquire ahead since access is limited and most likely available on weekdays.

Inside, 37 xenon arc lamps produce an artificial solar beam that mimics actual sunlight in space. This system was essential for testing the thermal conditions that spacecraft would face during their journeys.