unit7_硕士英语综合教程_课文翻译

Unit 7
Exploration is an important survival strategy in evolution.
探索是进化过程中一个重要的生存策略。

The migration of expansive species depends on exploring their immediate or distant surroundings for new food sources or safe habitats; it can also come as a result of population pressures or environmental changes.
数量不断扩张的物种的迁移有赖于对临近或遥远的新的食物来源或安全的栖息地进行探索，这是人口压力或是环境变化的结果。

The human species has added another reason for exploration, namely curiosity. This intellectual urge to explore the unknown led the great European explorers to the Americas, Australia and Antarctica between the fifteenth and seventeenth centuries.
而人类还增加了另外一个探索的原因，即好奇心。

这种对未知事物进行探索的思想冲动引领着伟大的欧洲探险家们在15世纪到17世纪之间来到了美洲，澳大利亚和南极洲。

Inquisitiveness about nature is also the driving force behind humans exploring the polar caps, climbing mountain peaks and diving into the abysses of the oceans.
对大自然的好奇心同样也是人类探索极地冰冠，攀登山峰和潜入海底背后的驱动力。

Now, the ultimate frontier to explore in the twenty-first century is space. Astronomical observations and satellites have already yielded immense knowledge about our solar system and the universe beyond.
现在二十一世纪探索的最终前沿便是太空。

天文观测和人造卫星已经为我们提供了关于太阳系内外的宇宙的丰富知识。

But these technologies can provide only a limited picture of what is out there; eventually humans themselves will have to travel to other planets to investigate them in more intimate detail.
但是这些技术只能提供一些有限的概况，让我们知道那里都有些什么。

最终人类还是要亲自前往其他星球以进行更详细的研究。

Tremendous advances in rocket and spaceship technologies during the past 50 years, driven mainly by national security considerations, the need for better communication or a desire to observe environmental changes and human activity on the ground, have made it possible to send humans into near-Earth orbit and to the Moon.
过去五十年间国家安全方面的考虑促使火箭和飞船技术取得了巨大进步。

现在，人类已经能够进入近地轨道和月球以便能够更好地实现通讯效果或是观察环境变化以及地面人类活动。

Conceivably, these advances will eventually make it possible to transport astronauts to other planets, and Mars in particular.可以想象，这些进展将最终能将宇航员送至其他
星球，尤其是火星。

But there are significant differences between exploring Earth and exploring space. First and foremost, space is an unforgiving environment that does not tolerate human errors or technical failure. For humans leaving Earth’s orbit for extended periods, there are even more dangers. One is the near absence of gravity in space; the presence of high-energy, ionizing cosmic ray (HZE) nuclei is another.
但是探索地球和探索太空有着巨大的差异。

首先，太空是一个不容许任何人为错误或技术故障的无情的环境。

对于长时间离开地球轨道的人而言风险会更多。

一个是太空中几近全无的重力，而另外一个则是高能量电离宇宙射线（HZE）核子的存在。

Because both zero gravity and cosmic rays would have severe health implications for astronauts on a Mars-bound spaceship, we first need to investigate their effects on cells, tissues and our hormonal and immune systems.
由于零重力和宇宙射线会对前往火星的飞船上的宇航员有着严重的健康影响，我们首先要研究它们对细胞，组织和人类荷尔蒙与免疫系统的影响。

However, although we are able to produce HZE nuclei on Earth and study their effects on biological material, we cannot simulate extended periods of low gravity and their additive effects on cells and tissues.
然而，尽管我们能够在地面制造HZE核子并研究其对生物材料的影响，但是我们无法长久的模拟低重力时段以及它们二者对细胞和组织的累加效应。

Thus, the International Space Station (ISS) will have an enormously important role in assessing the health dangers for humans in space and in the development of potential countermeasures.
因此，国际空间站（ISS）将会为人类在太空进行健康风险评估以及制定应对措施方面扮演重要的角色。

here is much information on the adaptation of astronauts to zero gravity (0g) in space and on their return to 1g on Earth. 关于宇航员是如何适应从太空中的零重力（0g）到地球的1g的信息已经有了很多，
Nevertheless, our understanding of these effects is not complete; nor have countermeasures to mitigate them been identified. 但是我们对这些影响的了解还是不够全面，也不明了有那些对策能够减轻这些影响。

Observations of astronauts travelling on the Space Shuttle and Russian cosmonauts’ long-term visits to the Mir space station indicate that time spent in 0g has serious effects on bone and muscle physiology and the cardiovascular system. For instance, the return from 0g to 1g leads to an inability to maintain an appropriate blood pressure when in an upright position — orthostatic intolerance—and insufficient blood flow to the brain.
通过对在航天飞船上和长期驻扎在俄罗斯和平号空间站上宇航员的观察发现零重力对骨骼和肌肉生理以及心血管系统都有着严重的影响。

例如，由0g返回至
1g会导致人无法在直立的体位维持正常的血压，即直立耐受不良，还会导致脑部供血不足。

Astronauts returning from orbit therefore have to rest for several minutes, and the time needed to normalize their blood pressure increases with the time spent in 0g. 因此，宇航员从轨道返回后需要休息几分钟。

恢复正常血压所需的时间和他们在零重力环境中所处的时间成正比。

This could mean that astronauts travelling to Mars—which would take at least one year in 0g—would need considerable time to readapt to gravity after landing there or after their return to Earth, unless we find a technological solution to the creation of artificial gravity on a spaceship.
这就意味着前往火星的宇航员无论是在登陆后还是在返回地球后都将需要相当长的时间来重新适应重力，因为他们至少将有一年的时间处于零重力状态，除非我们可以找到一个技术解决方案能在宇宙飞船上人工建立重力。

Moreover, there are other cardiovascular effects, such as cardiac arrhythmia and atrophy, which need to be studied in more detail before we can ensure the safety of astronauts on a Mars mission. Other effects of extended time in low gravity are loss of bone mass and muscle deterioration. Without adequate countermeasures, these could impair the ability of astronauts to perform necessary functions on a spacecraft or on the surface of Mars.
此外还有其他的心血管方面的影响，例如心律失常和心肌萎缩。

而这一切都需要更为详尽的研究，然后才能确保执行火星任务的宇航员的安全。

长时间处于低重力环境的其它影响还包括骨质的流失和肌肉退化，这些都有可能损害宇航员在飞船中或火星表面执行任务的能力。

The second main danger for human travelers is the presence of the aforementioned HZE nuclei in cosmic rays, because of the ionizing effect that they exert on atoms or molecules.
人类太空旅行的第二大风险就是前面提到的存在于宇宙射线中的HZE核子，因为他们能对原子或分子施加电离作用。

Although they do not reach the Earth’s surface because they are either absorbed by the atmosphere or deflected by Earth’s magnetic field, there are already some experimental data on the cancer-inducing properties of electrons, neutrons and protons in cosmic rays and other potential deleterious effects on biological material from numerous Earth-based experiments on laboratory animals.
尽管HZE核子无法到达地球表面，因为他们要么是被大气层所吸收，要么是被地球磁场影响而发生偏转，但是已经有实验数据表明宇宙射线中的电子，中子和质子有致癌作用以及其它一些对机体有害的潜在影响。

这些都已经在地球上的许多实验室动物中得到观察。

In addition, studies of the effects of the atomic bombs dropped on Japan in 1945 provided further data about the health dangers of radiation and high-energy nuclei.
此外，1945年在日本落下的原子弹的影响研究也为辐射和高能核子对健康的危害提供了进一步的数据。

However, cosmic rays are quite different from nuclear explosions because they include considerably higher numbers of HZE nuclei—leftovers from collapsing stars and supernova explosions that were thrown into space. The biological effects of HZE nuclei on cancer induction, the central nervous system, the immune system and the eyes are not well known, nor have the interaction of radiation effects at 0g been studied. Consequently we need to conduct many more experiments on Earth as well as on the ISS before the health and safety of astronauts travelling to Mars and beyond can be assured.
然而，宇宙射线与核爆炸还是有着很大不同。

因为宇宙射线包含大量的HZE核子，即坍塌的行星和超新星爆炸后释放到太空的残留物。

HZE核子对诱发癌症，中枢神经系统和眼睛的生理影响还不明确，辐射影响与零重力之间的相互作用也未获研究。

Consequently we need to conduct many more experiments on Earth as well as on the ISS before the health and safety of astronauts travelling to Mars and beyond can be assured.
因此，我们需要在地面上以及国际空间站进行更多的实验才能放心的保证往返火星和更远的行星的宇航员的健康和安全。

Ironically, the health dangers of radiation in space only became an issue when the potential dangers of material brought back from space were discussed.
具有讽刺意味的是，只有在从太空中带回的物质的潜在威胁得到讨论之后才能考虑太空辐射对健康的危害。

In 1975 I joined the Space Science Board of the US National Research Council (NRC) that considered, among other issues, the problem of whether objects returned from the Moon or elsewhere from space could harbor deleterious organisms that would be hazardous to life on Earth. The appropriate solution at that time was to isolate these objects and extensively sterilize them with X-rays or ultraviolet radiation, or high temperatures.
我曾在1975年加入美国国家研究理事会（NRC）的空间科学委员会，在诸多考虑事宜中就包括了从月球或是太空其他地方返回的物体是否会携带可能危及地球生命的有害生物。

那时合适的解决方案是隔离这些对象并用X射线或紫外线照射或是高温消毒。

Understanding and evaluating the physiological effects of radiation and gravity require not only experiments on Earth but also extensive research on the ISS with an adequate number of animals and/or human subjects. 要想理解和评估辐射和重力的生理作用不仅要求地球上的实验，还需要在国际空间站上对足够数量的动物和/或人体实验对象进
行广泛的研究。

However, further expansion and work on the ISS has been stalled because of cuts in funding
by NASA and, more recently, by the loss of the Columbia space shuttle in February 2003. In
addition, the ISS faces employment problems.
然而，由于美国宇航局经费的削减以及2003年2月哥伦比亚号航天飞机的失事，
国际空间站的工作和建设已经陷入停滞状态。

Originally, a crew of six or seven astronauts was planned for the ISS to maintain and run
the station and to do scientific experiments.
此外，国际空间站还面临人员问题。

原本计划安排六到七名宇航员来实行空间站
的维护和运转以及科学实验。

However, the shortage of funds means that there are not enough large space vehicles, such as space shuttles, available to transport crew, equipment and supplies and to serve as a rescue vehicle in case of a serious accident on the ISS.
然而资金短缺意味着没有足够大的太空飞行器，如穿梭机，来运输船员、设备和
供给，也无法满足在空间站遇到紧急事故的时候提供救援运输的需求。

Hence, for safety reasons the crew size was reduced in 2002 to three, because only the Russian spacecraft, Soyuz, was available and that can carry only three crew members in an emergency. The loss of the Columbia shuttle has exacerbated this problem. As the crew size has been decreased from six to three, most of the astronauts’ time will be spent on operation and maintenance of the station, which leaves little time for conducting scientific experiments. 因此，为了安全起见，船员的数量在2002年被减少到了三个。

因为只有俄罗斯
联盟号宇宙飞船可以使用，而该飞船在紧急情况下只能运载三名船员。

哥伦比亚
号飞船的损失加剧了这个问题。

由于船员的规模从六个减少到了三个，宇航员的
大部分时间被用于操作和维护空间站，而只能剩下一点时间来进行科学实验。

Without a significantly large infusion of funds to supply the equipment and to support a
larger crew, the collection of basic information about the hazards of space travel will not be
accomplished within the next 10–20 years.
没有可观的巨额资金输入来供应设备并支持更多的船员，科学家们将无法在未来
10到20年内完成对太空旅行风险的基本信息的收集。

We also need a continuing, rotating crew of at least six astronauts to obtain
epidemiologically significant data on the physiological and psychological effects of 0g on
astronauts and the efficacy of countermeasures.
为了获取流行病学有效的数据，我们同时还需要一个持续不断的，轮流上阵的至少六名宇航员来获取零重力对生理和心理的影响并验证对策的有效性。

Unless these experiments can be done, it will not be possible to guarantee the safety and well-being of astronauts on a three-year trip to Mars and back.
不完成这些实验就不可能保证长达三年的火星往返途中宇航员的安全和康健。

So, how can we satisfy our curiosity about the Solar System and beyond, and continue to investigate the nearest planets in more detail?
那么，要怎样做才能满足我们对太阳系内外进行探索的好奇心并继续更详尽地研究距离我们最近的行星呢？
There are three possible solutions. The first, and most obvious, is to use unmanned spacecraft to investigate the planets’ surface and to land, for example, on Mars or Europa —one of Jupiter’s moons —and return samples to Earth. This might very well be done within the next 10 years.
有三种可能的解决方案。

第一个，也是最为明显的一个就是使用无人驾驶飞船来探索行星的表面，比如说在火星或是欧罗巴（木星的一个行星）上登陆并将样本送回地球。

这有望在未来的十年内完成。

he second solution is to provide massively increased funding for the ISS. I cannot guess how much this would be, because, judging from past experience, there are large uncertainties in such estimates. And these funds would even eclipse the amount of money needed for a spacecraft that could transport a crew of six or seven astronauts on a three-year trip to Mars and back. 第二种方法是为国际空间站大量增加资金。

我无法估算需要多少资金，因为从过去的经验来看，这样的估计有很大的不确定性。

而这些资金甚至可能会超过建造一艘能够搭载六到七名宇航员从火星到地球为期三年的往返的太空飞船所需的费用。

In the present global economic circumstances, this is certainly not feasible without significant physical and financial collaboration and cooperation among many countries.
在目前全球经济的环境下，没有有效的物质和经济合作以及多国间的相互协同显然是无法实现的。

The third possible solution is to construct new lift-off capabilities and a much faster spacecraft to drastically reduce the time being spent in space and thus the radiation exposure and other stresses on astronauts.
第三个可能的解决方案是开发新的发射能力以及速度更快的太空飞船来大幅减少在太空中所花费的时间，从而降低辐射的照射和宇航员的其它压力。

Science reported that Russia is working on plans for a nuclear-powered spacecraft to accomplish this goal.
《科学》杂志报道说俄罗斯正在研制核动力飞船计划来实现这一目标。

However, it is hard to envisage take-off and landing scenarios that would satisfy environmental concerns.
然而，很难设想能够满足环境要求的起飞和着陆的场景。

Given the current situation, I therefore think that we will need to upgrade the ISS further and will have to stick with robot probes for at least the next 15 years before we can re-evaluate the rationale for sending humans to Mars.
鉴于目前的局势，我认为我们需要进一步改建国际空间站并至少在未来15年间使用机器人探测棒，然后才可以重新评估将人类送上火星的可能性。