the selection of facilities and their capabilities continue to evolve. Readers are referred to NASA websites for the most current information on facilities and equipment for research.†
The major intended purpose of the ISS is to provide an Earth-orbiting research facility that houses experiment payloads, distributes resource utilities, and supports permanent human habitation for conducting science and research experiments in a microgravity environment. It is expected to serve as a world-class orbiting national and international laboratory for conducting high-value scientific research and providing access to microgravity resources for major areas of science and technology development. The ISS sustains a habitable living and working environment in space for extended periods of time, and astronauts become not only the operators of experiments but also the subjects of space research. NASA has partnered with four other space agencies on the ISS Program: the Russian Federal Space Agency (Roscosmos), the Canadian Space Agency (CSA), the Japanese Aerospace Exploration Agency (JAXA), and the European Space Agency (ESA).
Based on international barters, the United States owns 50 percent of all science/experiment racks located in the ESA and JAXA laboratory modules. The U.S. principal investigators working with NASA have access to these facilities but not necessarily to facilities owned and operated exclusively by ISS partners. Exclusively owned Russian facilities are a good example of the latter.
The ISS can support a variety of fundamental and applied research for the United States and international partners. It provides a unique, continuously operating environment in which to test countermeasures for long-term human space travel hazards, to develop and test technologies and engineering solutions in support of exploration, and to provide ongoing practical experience living and working in space. However, with the retirement of the space shuttle fleet, there will be no U.S. government space transportation system available to carry astronauts or payloads to the ISS.
The main advantages for conducting life and physical sciences research on the ISS are the access to the microgravity environment, long-duration time periods for research, and the extended flexibility the crew and principal investigators will have to perform the experiments onboard. The ISS also provides the opportunity to repeat or modify experiments in real time when necessary. In addition, the human aspect of crew participation, as both experimenter and subject, is invaluable in human life sciences research. Finally, the ISS provides an analog environment for simulating long-term deep-space human exploration, which allows NASA the opportunity to prepare humans, machines, and organizational and mission planning for the rigors of the next chapter in human space exploration.
Science payload operations on the ISS are supported by a wide variety of programs, equipment, and laboratory modules. The following are significant payload components:
• U.S. Laboratory,
• Facility-Class Payloads,
• Attached External Payloads,
• Centrifuge Accommodation Module (this program was canceled),‡
• Japanese Experiment Module,
• Columbus Orbital Facility, and
• Russian Research Modules.
The U.S. Laboratory, also known as Destiny, is the major U.S. contribution of scientific capacity to the ISS. It provides equipment for research and technology development and houses all the necessary systems to support a controlled-environment laboratory. Destiny provides a year-round, shirtsleeve atmosphere for research in areas such as life sciences, physical sciences, Earth science, and space science research. This pressurized module is
‡ Utilization of this major component for onboard experiments was to commence in 2008, and was included because it has been cited in past NRC reports as a critical capability for space life sciences research.