Abstract
Since the early days of manned spaceflight, hazardous effects of the space environment on living organisms have been disputed. With the continuous manning of the International Space Station, the planned Chinese space station, and renewed interest in returning to the Moon and sending manned flights to Mars, identifying and addressing the potential outcomes of long-term space exposures is critically important. Space-flown and ground-based research Much progress has been made towards the understanding of the effect of space environmental factors, especially microgravity and radiation, on living organisms. During the space exploration of the 1970s, physiological changes in several organ systems due to weightlessness were identified. Some of the adverse effects are a decline in cellular immune responses (1{ 3), cardiovascular deconditioning (4), bone deterioration (5), and muscular atrophy (6). Furthermore, simulated microgravity studies have shown increased virulence in microorganisms (7). Over the past 30 years, a number of in vitro studies have been carried out in space. However, the cost and logistics of conducting space-flown studies have not allowed indepth interpretation of the data because of small sample sizes (8). Therefore, ground-based research has become common in space life sciences. Those simulated microgravity studies include head-down bed rest for humans (9), tail suspension for rodents (10), and cell and microorganism cultures with high aspect ratio vessel (HARV) bioreactors (11;12) and random positioning machine (RPM) (13).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have