What Will Still Remain Unknown, and What Risk Does This Represent?

The benefits gained from pursuing these strategies will be not only a reduction by a factor of 2 or more in the uncertainty in estimates of the risk of late effects for crew members exposed to radiation in space, but also greater understanding of CNS and other effects about which little is currently known. These benefits will result in a narrowing of the scope of the types and designs of shielding that need to be considered for crew protection, and thus should result in a significant cost savings. The liability of following these strategies is that the time required to complete them may delay a decision on shielding design and consideration of any near-term (within 25 years) launch dates if suitable resources are not made available to complete the research expeditiously.

Since these research strategies are narrowly focused and based entirely on current understanding of space radiation issues, there is also no guarantee that this approach will necessarily address all of the significant radiation hazards for crews of deep-space missions. Utilizing a wider range of radiation and biological models could lead to recognition of previously unappreciated hazards for those crews and reveal useful new avenues of research.

References

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8. Parshad, R., Price, F.M., Pirollo, K.F., Chang, E.H., and Sanford, K.K. 1993. Cytogenetic response to G2-phase X-irradiation in relation to DNA repair and radiosensitivity in a cancer-prone family with Li-Fraumeni syndrome. Radiat. Res. 136: 236–240.

9. Bender, M.A., Viola, M.V., Riore, J., Thompson, M.H., and Leonard, R.C. 1988. Normal G2 chromosomal radiosensitivity and cell survival in the cancer family syndrome. Cancer Res. 48: 2579–2584.

10. Scott, D., Spreadborough, A.R., Jones, L.A., Robert, S.A., and Moor, C.J. 1996. Chromosomal radiosensitivity in G2-phase lymphocytes as an indicator of cancer predisposition. Radiat. Res. 145:3–16.

11. Scott, D., Spreadborough, A., Levine, E., and Roberts, S.A. 1994. Genetic predisposition in breast cancer. Lancet 344: 1444.

12. Kranert, T., Schneider, E., and Kiefer, J. 1990. Mutation induction in V79 Chinese hamster cells by very heavy ions. Int. J. Radiat. Biol. 58: 975–987.

13. Belli, M., et al. 1993. Inactivation and mutation induction in V79 cells by low energy protons: Re-evaluation of the results at the LNL facility. Int. J. Radiat. Biol. 63: 331–337.

14. Stoll, U., Schmidt, A., Schneider, E., and Kiefer, J. 1995. Killing and mutation of Chinese hamster V79 cells exposed to accelerated oxygen and neon ions. Radiat. Res. 142: 288–294.



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