Pickens writes: "Science Daily News reports that human missions to Mars, as well as all other long-term space flights might be compromised by disease first because space travel appears to weaken astronauts' immune systems; and second, because it increases the virulence and growth of microbes. "When people think of space travel, often the vast distances are what come to mind first," says Jean-Pol Frippiat from Nancy-University in France, "but even after we figure out a way to cover these distances in a reasonable amount of time, we still need to figure out how astronauts are going to overcome disease and sickness." Frippiat says that studies show that immune systems of both people and animals in space flight conditions are significantly weaker than their grounded counterparts and that common pathogens such as Salmonella, E. coli and Staphylococcus reproduce more rapidly in space flight conditions, leading to increased risk of contamination, colonization and serious infection. "We are unlikely to remain healthy when leaving earth for prolonged periods," says Luis Montaner, Editor-in-Chief of The Journal of Leukocyte Biology. "Unfortunately, because spacecraft technology is way ahead of our understanding of how to maintain human health, disease-free survival after reaching Mars or establishing a colony on the Moon may be problematic.""