میکروگرانشی و اکتشافات انسان از چالش های فن آوری فضا

If humans are to explore space beyond low-earth orbit, their health and welfare must be ensured, not only for survival in harsh environments but also so that they can work productively. The requisite technologies, and human physiology itself, are subject to reduced levels of gravity that are indigenous to space travel. Numerous studies have shown that it will require many years of intensive research to develop reliable, efficient, and self-sustaining technologies and to understand the effects of gravity on humans. The research community that was developed to provide crucial specific information has essentially been deactivated because of budget constraints. Thus, the great engineering challenge—to develop advanced and novel technologies that will enable further space exploration—will remain for future generations.

The human exploration of space is one of the great expeditions of discovery in history and it also presents intriguing challenges and opportunities. Power generation and storage, propulsion, life support, and hazard protection systems are essential to ensure the long-term survival and productivity of the missions and, ultimately, extraterrestrial colonization. One of the most challenging aspects of human space travel within the solar system is that levels of gravity are very different from terrestrial levels, ranging from microgravity in free fall, such as in low-earth orbit, to greatly reduced gravity on the surface of extraterrestrial bodies. Gravity affects many biophysicochemical phenomena that play a vital role in mission-enabling and -enhancing technologies and in human physiology, and it also suppresses other phenomena that become important as the gravity level is reduced. The Apollo, space shuttle, and space station programs have shown that humans can live productively in space. In all those missions, however, vital needs such as oxygen, water, and waste management depend entirely on resupply, with associated high costs and up-weight mass requirements. For extended missions on the Moon and beyond low-earth orbit, resupply is not feasible, which means new advanced technologies must be developed that are reliable, efficient, and self-sustaining. Furthermore, they must operate in alien environments under unprecedented conditions. Most processes and systems involved in such technologies are gravity-dependent in ways not completely understood. Thus, the design of systems to sustain humans for space exploration presents enormous challenges to engineers. There is little doubt the development of advanced closed-loop and self-contained technologies for recycling water, air, and waste could help alleviate environmental problems on earth as well. Since no databases for designing such technologies exist, requirements-driven research must be performed. The space station was intended for this purpose and eventually the closed-loop systems could be tested on the Moon.