VOA慢速英语2015 科学家测试太阳能动力（在线收听）

Scientists Testing Space Propulsion by Light 科学家测试太阳能动力

Can the sun provide power for a spaceship to travel to the edge of our solar system? The answer may come from a small satellite. A Delta V rocket carried the satellite into space earlier this (last) month. The rocket was launched from Cape Canaveral Air Force Station in Florida.

太阳能为飞行到太阳系边缘的飞船提供动力吗？答案可能来自一枚小卫星，上月早些时候德尔塔五号载着这颗卫星进入太空，这枚火箭是在佛罗里达州卡纳维拉尔角空军基地发射的。

The satellite is designed to test the effectiveness of what is called solar sail propulsion. Its large sail will catch solar wind and slowly reach what scientists hope to be an extreme speed.

设计这颗卫星是为了测试所谓太阳帆推进技术的有效性，其巨大的风帆能捕捉太阳风，慢慢抵达科学家所希望的极限速度。

The satellite is called CubeSat. It is about the size of a loaf of bread. CubeSat was designed by a non-profit group, The Planetary Society. Bill Nye is the chief executive officer of the society. He says the satellite will test whether sunlight can be used as a propulsion force for space travel.

这颗卫星名叫CubeSat，大约有一块面包大小。CubeSat是由非盈利组织行星协会设计的，比尔·奈伊是该协会的首席执行官，他说这颗卫星将测试是否可将太阳光用作太空飞行的推动力。

"This may seem incredible at first, but it is nevertheless true that sunlight, or light, has momentum even though it has no mass. Photons have no mass but they still impart momentum when they strike an object...it's a tiny, tiny amount of momentum. Nevertheless, if you have a big enough sail, as we call it, and [a bus or spacecraft with] a low enough mass, it will get a push."

“这一想法最初看来不可思议，尽管太阳光没有质量，却有动量。光子没有质量，但它们在碰撞到物体时会传递动量，这是一种很微小的动量，但是如果风帆足够大，而飞船的质量足够小，就能获得推动力。”

Scientists believe that this method of propulsion will reduce the cost of space exploration for universities and even private individuals.

科学家认为这种推动方式能减少大学甚至个人探索太空的成本。

The sail is 32-square meters long. It is made of Mylar, a material that is only one fourth as thick as human hair. Bill Nye says laboratory tests of the sail were successful. But he says testing the sail in space will be critical.

这个风帆有32平米大小，是由厚度只有人头发四分之一的聚酯薄膜材料制成。比尔·奈伊说这种风帆的实验室测试很成功，但他说在太空中测试是非常关键的。

"This first time out is a test. The big question, from an engineering standpoint not a physics standpoint, is getting the sails to deploy. This is where everything goes wrong."

“第一次启程是测试，这是个大问题，从工程的角度而非物理学角度来说，最大的问题是让风帆展开，这是容易出错的地方。”

The Planetary Society reported that the satellite reached its orbit and that all of its systems appeared healthy. The group says the solar sail can be seen from the earth in the middle of June.

行星协会报告称该卫星已经进入轨道，一切系统都运转正常，该组织称6月中旬可以从地球上看到这个太阳帆。

Words in This Story

critical – adj. extremely important

momentum – n. the force that something has when it is moving

photon – n. a tiny particle of light or electromagnetic radiation

propulsion – n. the force that moves something forward; the force that propels something