Effect of weightlessness on mineral metabolism; Metabolic studies on skylab orbital space flights

After eight years of preparation, which took place before and during the Apollo-Moon space-flight series, the National Aeronautics and Space Administration in May 1973 launched into orbit a cylinder 22 feet in diameter and 48 feet in length called the Skylab Orbital Workshop. The living quarters and storage area of this cylinder contained nearly all of the life support and scientific experimentation equipment and supplies for three separately launched three-man astronaut crews. The first crew remained in orbit for 28 days, the second for 60 days, and the last crew for 84 days.