Spacelab-3, Space Shuttle Program, NASA

The primary purpose of the Spacelab-3 mission was to conduct materials science experiments in a stable low-gravity environment. In addition, the crew performed research in life sciences, fluid mechanics, atmospheric science, and astronomy. Spacelab-3 was equipped with several new minilabs, special facilities that would be used repeatedly on future flights. Two elaborate crystal growth furnaces, a life support and housing facility for small animals, and two types of apparatus for the study of fluids were evaluated on their inaugural flight. In this photograph, astronaut Don Lind observes the mercuric iodide growth experiment through a microscope at the vapor crystal growth furnace. The goals of this investigation were to grow near-perfect single crystals of mercuric iodide and to gain improved understanding of crystal growth by a vapor process. Mercuric iodide crystals have practical use as sensitive x-ray and gamma-ray detectors, and in portable detector devices for nuclear power plant monitoring, natural resource prospecting, biomedical applications in diagnosis and therapy, and in astronomical instruments. Managed by the Marshall Space Flight Center, Spacelab-3 (STS-51B) was launched aboard the Space Shuttle Orbiter Challenger on April 29, 1985.