托福听力:月亮和火星重力研究
来源：沪江听写酷
2011-09-16 14:30
Located at the NASA Research Center in Iowa is a 5,000 gallon vat of water, and inside the tank is an underwater treadmill designed by Dava Newman, an aerospace engineer. For four years Newman observed scuba divers as they simulated walking on the Moon and on Mars on her underwater moving belt. She wanted to discover how the gravity of the Moon and of Mars would affect human movement.
To do this, Newman attached weights to the divers and then lowered them into the tank and onto the treadmill. These weights were carefully adjusted so that the divers could experience underwater the gravity of the Moon and of Mars as they walked on the treadmill. Newman concluded that walking on Mars will probably be easier than walking on the Moon. The Moon has less gravity than Mars does, so at lunar gravity, the divers struggled to keep their balance and walked awkwardly. But at Martian gravity, the divers had greater traction and stability and could easily adjust to a pace of 1.5 miles per hour.
As Newman gradually increased the speed of the treadmill, the divers took longer, graceful strides until they comfortably settled into an even quicker pace. Newman also noted that at Martian gravity, the divers needed less oxygen.
The data Newman collected will help in the future design of Martian space suits. Compared to lunar space suits, Martian space suits will require smaller air tanks; and to allow for freer movement, the elbow and knee areas of space suits will also be altered.
坐落在Iowa的美国国家航空和宇宙航行局研究中心，是一个有5000加仑水的大水槽。航空工程师D.N.在水槽中间设计了一个水下训练道。四年来，N观察潜水员们在她的水下移动带上模仿在月亮和火星上走路的情况。她想揭示月亮和火星的引力是如何影响人类运动的。为了做这项实验，N把重物加在潜水员身上，然后将他们放入水槽中的训练道上。这些重物是精心设计出来的，以保证潜水员能在水下训练道上走路是感觉到月亮和火星的引力。N得到的结论是，很可能在火星上走路比在月亮上走路容易。月亮的引力比火星小，所以在月亮引力下，潜水员挣扎着保持平衡，走路动作笨拙。但是在火星引力之下，潜水员有更大的牵引力和稳定性能够很容易地适应每小时1.5英里的步速。当N逐渐对训练带加速，潜水员用更长、更优雅的大步去调整直到适应更快的速度。N也注意到在火星引力下，潜水员需要更少的氧气。N收集的数据可以极大地帮助未来的火星太空服设计。与月亮太空服相比，火星太空服需要更小的空气罐。与此同时，为能够保证自由活动，航空服的肘和膝盖部位也会有所调整。
——译文来自: vicky_yurong