Review of NASA Plans for the International Space Station (2006)

NASA currently defines the mission objectives for the ISS in support of extended crewed exploration of space as follows:

• Develop and test technologies for exploration spacecraft systems,

• Develop techniques to maintain crew health and performance on missions beyond low Earth orbit, and

• Gain operational experience that can be applied to exploration missions.

The panel agrees that these are appropriate and necessary roles for the ISS, although it has concerns (discussed below) about the areas omitted from this list. Although it seems unlikely that the ISS will have to play a critical research role in support of lunar sorties (because of their short duration and capability for rapid return), the panel concluded that the ISS provides an essential platform for research and technology testing in support of long-term human exploration, including lunar outpost missions and, most especially, the human exploration of Mars. Indeed, it is not certain that the risks involved in sending humans on long-range exploration can be mitigated to acceptable levels without precursor experimentation and testing aboard the ISS. Understanding the risks of radiation exposure and interactions, cumulative biological effects in long-term microgravity environments, and effects on human behavior and performance, as well as long-term verification of hardware and biological countermeasures and life-cycle testing, will all require the ISS as the only available capability for tended experiments in a free-fall environment for periods of time that approximate a Mars outpost mission.

As noted previously, the panel lacked both the time and the necessary data to attempt a comprehensive assessment of the diverse research issues that have to be addressed to enable NASA’s human exploration plans. A number of broad areas important to exploration were identified in past studies, and this report discusses several of them to show the kinds of research and testing that are needed and could be performed on the ISS. However, a successful exploration program will require a much better understanding of the improved technologies and capabilities needed to support a reliable and affordable exploration program, and the research and operations demonstrations needed to support their development, than NASA has at present or appears to be in the process of developing.^a

Recommendation: NASA should give priority to full use of ISS capabilities for research, technology, and countermeasure testing and operations demonstrations in preparation for human exploration of the Moon, Mars, and beyond.

Recommendation: NASA would benefit from, and should consider, a comprehensive study that would rigorously review the wide range of biomedical and technological issues relevant to exploration, identify

specific research projects and testbed experiments needed to support biomedical countermeasures and exploration technology development, and prioritize these in terms of such factors as mission importance, range of use, timelines, and probability of success.

The panel noted with special concern the potential long-term impact of recent decisions to eliminate delivery of certain ISS research facilities, specifically the centrifuge accommodation module and the planned animal habitats and holding racks and the life sciences glove box, and to eliminate or severely downgrade fundamental research in previously funded areas of physical and life sciences. Previous reports have emphasized the importance of areas of fundamental biological and microgravity research in the development of new technologies and the mitigation of space-induced risks to human health and performance both during and after long-term spaceflight.^1-3 Chapters 4 and 5 of the present report summarize several priority areas of fundamental biomedical and physical science research that are crucial to achieving acceptable levels of risk in spaceflight beyond low Earth orbit. The panel fears that loss of these programs may limit or impede development of such technologies and biological countermeasures and it notes that, once lost, neither the necessary research infrastructures nor the necessary communities of scientific investigators can survive or be easily replaced.

Recommendation: NASA should reconsider the role of the ISS in fundamental research in microgravity and biological sciences and the facilities essential for this research, with the aim of acquiring new knowledge critical to mitigating the multiple risks of long-term spaceflight beyond low Earth orbit.

As discussed in earlier reports, neither sufficient time for research and testing nor a sufficient number of volunteers for human experimentation can be afforded by a three-person crew,^4-8 much less the current reduced number of two. Completion of ISS research and testing essential for human missions to Mars and beyond will require a full six-person crew to enable astronauts to give adequate time and effort to these activities.

Recommendation: NASA should give top priority to restoring the crew size of the ISS to at least six members at the earliest possible time, preferably by 2008.

1. Institute of Medicine (IOM). 2001. Safe Passage: Astronaut Care for Exploration Missions. National Academy Press, Washington, D.C.

2. National Research Council (NRC). 1998. A Strategy for Research in Space Biology and Medicine in the New Century. National Academy Press, Washington, D.C.

3. NRC. 2003. Assessment of Directions in Microgravity and Physical Sciences Research at NASA. The National Academies Press, Washington, D.C.

4. NRC. 2003. Factors Affecting the Utilization of the International Space Station for Research in the Biological and Physical Sciences. The National Academies Press, Washington, D.C.

5. NRC. 1998. A Strategy for Research in Space Biology and Medicine in the New Century.

6. NRC. 2000. Review of NASA’s Biomedical Research Program. National Academy Press, Washington, D.C.

7. IOM. 2001. Safe Passage: Astronaut Care for Exploration Missions.

8. IOM and NRC. 2006. A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap. The National Academies Press, Washington, D.C.