L. Chen, E.A. Selimovic, M. Daunis, T.A. Bayers T, L.J. Vargas, I.T. O’Brien, C.B. McEnroe, A.E. Kozerski, A.C. Vanhoover, W.D. Gray and J.F. Caruso
countermeasures that sought to abate musculoskeletal losses (Kramer et al., 2017; Trappe et al., 2007). Those countermeasures included flywheel-based resistive exercise (Trappe et al., 2007) and high-intensity jump training (Kramer et al., 2017). Results showed that concurrent exercise reduced muscle mass and strength losses in those who received the experimental treatment as compared to bed-rested controls, yet neither countermeasure addressed bone losses, which is an important in- and postflight concern (Kramer et al, 2017; Trappe et al., 2007). However, a recent study with
There is a large body of research ( Licato and Grimm, 1999 ; Uva et al., 2002 ; Gridley et al., 2009 ; Singh et al., 2010 ; Thiel et al., 2012 ; Hauschild et al., 2014 ; Martinez et al., 2015 ; Nickerson et al., 2016 ) showing that exposure to microgravity leads to suppressed immunity in both rodents and humans. The downregulation of the immune system is measured by a decreased number of T-cells, alterations in immune cell subsets, epigenetic regulation, slower proliferation rate, and other immunological parameters. Altered gravity has
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 Lin, X., Fulton, N., and Horn, M., 2014, “Quantification of high level safety criteria for civil unmanned aircraft systems,” Proceedings of IEEE Aerospace Conference , Big Sky, pp. 1-13.
 Loh, R., Bian, Y., and Roe, T., 2009 “UAVs in civil airspace: Safety requirements,” IEEE Aerospace and Electronic