Cosmic Ray Detectors

Walking past a childcare center near the University of Chicago Hospitals, you may catch a glimpse of a battered white object marked “NASA” sitting in an alley next to an equally battered white sphere and a yellow storage container.

The storage container holds the remains of the “Chicago Egg,” a 2.5-ton, 12-foot tall cosmic ray detector that flew on the Space Shuttle Challenger in 1985 as part of the Spacelab 2 (STS-51F) mission. It was among the largest pieces of scientific equipment ever to fly on a NASA space shuttle.

While the site of the first self-sustaining nuclear reaction (two blocks away) enjoys national landmark status, University of Chicago astrophysicists’ work on cosmic rays is less well-recognized. The objects in this alley are the legacy of this pioneering work. (Also on this mission were specially designed Coca-Cola and Pepsi cans intended to deliver soda to astronauts in the weightlessness of space. The cans apparently did not work as well as expected and were removed from the menu on future shuttle flights, but the cosmic ray detector worked better than expected and provided a treasure trove of data.)

After the tragic Challenger explosion the following year and the subsequent grounding of the shuttle fleet, researchers switched to high-altitude balloons to bring their cosmic ray detectors to the edge of space. The two battered white objects are from these later balloon-borne missions.

Apart from museums, this is quite possibly the closest you can get in the Chicago area to an object that has been in space.