S k y l a b

America's first experimental space station, Skylab, was designed for long durations.

Skylab program objectives were twofold: To prove that humans could live and work in space for extended periods, and to expand our knowledge of solar astronomy well beyond Earth-based observations. The program was successful in all respects despite early mechanical difficulties.

Skylab was launched into Earth orbit by a Saturn V rocket on May 14, 1973. Through the use of a "dry" third stage of the Saturn V rocket, the station was completely outfitted as a workshop area before launch. Crews visited Skylab and returned to Earth in Apollo spacecraft.

Three, three-man crews occupied the Skylab workshop for a total of 171 days and 13 hours. It was the site of nearly 300 scientific and technical experiments, including medical experiments on humans' adaptability to zero gravity, solar experiments and detailed Earth resources experiments.

The empty Skylab spacecraft returned to Earth on July 11, 1979, scattering debris over the Indian Ocean and the sparsely settled region of Western Australia.

Ontology- defined.

Ontology (from onto-, from the Greek ὤν, ὄντος "being; that which is", present participle of the verb εἰμί "be", and -λογία, -logia: science, study, theory) is the philosophical study of the nature of being, existence or reality as such, as well as the basic categories of being and their relations. Traditionally listed as a part of the major branch of philosophy known as metaphysics, ontology deals with questions concerning what entities exist or can be said to exist, and how such entities can be grouped, related within a hierarchy, and subdivided according to similarities and differences.