Acta Astronautica 56 (2005) 851–858 www.elsevier.com/locate/actaastro HumanstoMars:Afeasibilityandcost–benefitanalysis  Bethany L. Ehlmann a , * , Jeeshan Chowdhury b , Timothy C. Marzullo c , R. Eric Collins d , Julie Litzenberger e , Stuart Ibsen f , Wendy R. Krauser g , Brandon DeKock h , Michael Hannon i , Jessica Kinnevan j , Rebekah Shepard k , F. Douglas Grant l a Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri 63130, USA b School of Medicine, University of Alberta, Canada c Neuroscience Program, University of Michigan, USA d School of Oceanography, University of Washington, USA e Department of Mechanical Engineering, Biomedical Engineering Division, Stanford University, USA f Department of Zoology, University of Hawaii, Manoa, USA g NASA Ames Research Center, Moffett Field, California, USA h Department of Mechanical Engineering, University of Oklahoma, USA i Department of Mechanical Engineering, University of Notre Dame, USA j Department of Electrical Engineering, University of New Hampshire, USA k Department of Geology, University of California, Davis, USA l Department of Geological Sciences, Arizona State University, USA Available online 8 March 2005 Abstract Mars is a compelling astrobiological target, and a human mission would provide an opportunity to collect immense amounts of scientific data. Exploration alone, however, cannot justify the increased risk. Instead, three factors drive a human mission: economics, education, and exploration. A human mission has a unique potential to inspire the next generation of young people to enter critically needed science and engineering disciplines. A mission is economically feasible, and the research and development program put in place for a human mission would propel growth in related high-technology industries. The main hurdles are human physiological responses to 1–2 years of radiation and microgravity exposure. However, enabling technologies are sufficiently mature in these areas that they can be developed within a few decade timescale. Hence, the decision of whether or not to undertake a human mission to Mars is a political decision, and thus, educational and economic benefits are the crucial factors. © 2005 Elsevier Ltd. All rights reserved. Keywords: Mars; Human; Mission; Feasibility; Technical; Political  Group report of the 2002 NASA Astrobiology Academy. * Corresponding author. Campus Box 1169, 1 Brookings Drive, St. Louis, Missouri 63130, USA, Tel.: +13145414241; fax: +13149354998. E-mail address: bethany.ehlmann@wustl.edu (B.L. Ehlmann). 0094-5765/$ - see front matter © 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.actaastro.2005.01.010