are at least four level 3 technologies in TA06 related to space radiation prediction, monitoring, and protection that would benefit from the ability to use the ISS as a testing facility.

Astronauts and machines are inevitably exposed to foreign environments during space exploration. Therefore, there is a continued need for exploration surface environment chambers, consisting of both small and large ground-based facilities that simulate space environments in terms of vacuum, CO2 dust, and solar radiation (but not reduced gravity). Such facilities are vital to the future development of EVA suits, rovers, and habitats.

There are only a few locations where synergistic effects of reduced gravity and high radiation can be studied on biological and physical systems prior to committing to a 500+ day mission to Mars. A centrifuge in high Earth orbit or on the ISS would enable testing at all gravity levels of interest, from 0 to 1 g, but there are no plans to build such facilities, and they would not accommodate human subjects. If NASA human exploration returns to the surface of the Moon, testing on the moon would provide the opportunity to conduct long-term research and testing in 1/6 g. Although such data would not be taken in the microgravity environment experienced during a transit to and from Mars or the 3/8 g experienced on the Mars surface, this data would provide much needed information that is not available from current testing in the microgravity environment of the ISS or the 1-g environment on Earth.

Finding. Facilities. Adequate research and testing facilities are essential to the timely development of many space technologies. In some cases, critical facilities do not exist or no longer exist, but defining facility requirements and then meeting those requirements fall outside the scope of NASA’s Office of the Chief Technologist (and this study).

PROGRAM STABILITY

The productivity and the effectiveness of technology development programs are diminished when the direction, content, and/or funding of those programs abruptly change from year to year. Some redirection of effort based on program progress, results, and new understanding is appropriate, but when substantial changes occur repeatedly and unexpectedly, those changes can be extremely disruptive, especially to university research programs. Reconstituting lost capabilities or recovering from major changes in program direction can take years. Stability is important in the short term to avoid disrupting individual programs and in the long term to ensure that other federal agencies, industry, academia, and foreign organizations recognize NASA as a reliable partner.

Maintaining a stable research and technology development program can be particularly difficult when that program is too closely tied to near-term mission priorities. For example, after the Apollo program, Project Viking and other planetary probes capitalized on the ablative heat shield technologies developed for the Apollo spacecraft. However, in more recent years, the focus has been more on the reusable thermal protection systems used by the space shuttle for return from low Earth orbit. During this era, much momentum was lost in the ablative material development and supply chain, and there is a concern that reusable thermal protection systems (TPS) will suffer the same fate in the coming years. In fact, key materials suppliers are already terminating production, and technology development in this area is faltering (Grantz, 2011).

Disruptions caused by reduced budgets and changing goals of space technology programs within NASA and other federal agencies can cascade from one agency to another. Reduced support by one agency can threaten the viability and the continuation of multiagency efforts. In some cases, the resulting disruptions have led to a loss of experienced technology specialists. These losses impact NASA as well as the national aerospace community (NRC, 2009, 2010). Consequently, the need to restore these capabilities across NASA, industry, and academia and to preserve stability and continuity in a core space technology program has become a national issue.

Program stability has been a long-standing concern to the EDL community. Their concern for maintaining core capabilities, skills, and knowledge raises the issue of the role NASA should play in maintaining knowledge so it is not lost (e.g., losing TPS capabilities after Apollo) between periods of peak demand from major mission programs. Ideally, EDL research projects, technology demonstrations, and interim technology goals in the roadmap would smooth out these peak demands while building on past work to meet future requirements. A successful technology program will preserve test capabilities and advance key technologies at a steady pace that does not



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