NASA NTRS2004
NASA exploration goals include returning humans to the moon by 20 15-2020 as a prelude for human exploration of Mars and beyond. The number of human flight subjects available during this very short time period is insufficient to solve high-risk problems without data from animals. This presentation will focus on three questions: What do we know? What do we need to know? Where do we go from here?: roles for animals in the exploration era. Answers to these questions are based on flight and ground-based models using humans and animals. First, what do we know? Adult humans have spent less than 1% of their lifespan in space while juvenile rats have spent almost 2%. This information suggests that our data are rather meager for projecting to a 30-month mission to Mars. The space platforms for humans have included Skylab, STS/MIR, and STS/ISS and for animals have included the unmanned Bion series and shuttle. The ground-based models include head-down bedrest in humans (BR) and hindlimb unloading in rodents (HU). We know that as gravity decreases, the impact forces generated by the body during locomotion decrease. For example, on Earth, your legs supports approximately 1 body weight (BW) when standing, 1.33BW when walking, and 3BW when jogging. On Mars, the same activity would generate 0.38BW standing, 0.5BW walking, and 1BW when jogging. In space, no impact load is generated, as gravity is minimal.