Morelos-B was the second in a series of communications satellites for Mexico. It was designed to provide telephone, television and wire services to Mexico through a total of 22 transponders. The first Morelos spacecraft was deployed from the orbiter Discovery in June 1985.
The Aussat spacecraft provided domestic communications to Australia's population of 15 million. The system was also used to improve both maritime and air traffic control communications, relay digital data for business purposes, provide standard telephone communications and direct satellite-to-home television broadcasts to major cities, as well as to the bush country.
RCA Satcom K-2 was the second of three planned communications satellites, operating in the Ku-band part of the spectrum, launched for RCA American Communications, Inc. The spacecraft was designed to provide entertainment and educational television programming coverage for the 48 continental United States.
Life sciences experiments performed during the STS-61B mission were those classified as Detailed Supplementary Objectives (DSOs). A DSO is a NASA-sponsored investigation performed by Space Shuttle crewmembers, who serve as the test subjects. These studies are designed to require minimal crew time, power and stowage. Biomedical DSOs focus on operational concerns, including space motion sickness, cardiovascular deconditioning, muscle loss, changes in coordination and balance strategies, radiation exposure, pharmacokinetics and changes in the body's biochemistry.
Working in the payload bay, astronauts assembled two structures, Experimental Assembly of Structures in Extravehicular Activity (EASE) and Assembly Concept for Construction of Erectable Space Structures (ACCESS), during two extravehicular activities (EVAs). The first EVA was devoted to experiments studying human performance of construction tasks in space. The second was dedicated to supplementary experiments that explore alternative construction techniques and practice Space Station maintenance scenarios.
Other payloads were Diffusive Mixing of Organic Solutions, Telesat of Canada, Protein Crystal Growth Experiment, Continuous Flow Electrophoresis Experiment and the IMAX cargo bay camera. Several experiments sponsored by Mexico were flown, including Effects of Sapctial Environment on the Reproduction and Growing of Bacteria, Transportation of Nutrients in a Weightless Environment, Electropuncture and Biocybernetics in Space, Effects of Weightlessness and Light on Seed Germination, and Photography of Mexico.
Atlantis landed after a successful mission at Edwards Air Force Base in California on December 3, 1985.