回望NASA探索太阳系的50年（英文翻译）

50 YEARS OF SOLAR SYSTEM EXPLORATION:HISTORICAL PERSPECTIVES （原文链接）

回望NASA探索太阳系的50年（英文翻译）

封面

原文：
AFTER MANY FAILURES to get to the Moon and to the planets beyond,Mariner 2 successfully flew by Venus in December 1962. This historicmission began a spectacular era of solar system exploration for NASA and many other space agencies. With the tremendously successful flyby of the Pluto system by the New Horizons spacecraft in July 2015, humankind completed its initial survey of our solar system, and the United States became the only nation to reach every planet from Mercury to the dwarf planet Pluto with a space probe.
Solar system exploration has always been and continues to be a grand human adventure that seeks to discover the nature and origin of our celestial neighbors and to explore whether life exists or could have existed beyond Earth. Before Mariner 2, everything we knew about our solar system came from ground-based telescope observations and from analysis of meteorites.
This limited perspective could not begin to reveal the diversity and the true nature of our solar system. In this brief introduction, we address how NASA and other space agencies have approached a comprehensive series of missions for the last half century of solar system exploration.

翻译：
1962年12月，水手2号成功地飞越了金星。这个历史性的任务开启了美国宇航局和许多其他太空机构探索太阳系的壮观时代。2015年7月，新地平线号太空船成功飞越冥王星系统，人类完成了对太阳系的初步调查，美国成为唯一一个用太空探测器到达从水星到矮行星冥王星的所有行星的国家。
太阳系探索一直是并将继续是人类的一次伟大冒险，旨在发现我们天体邻居的本质和起源，并探索地球以外是否存在或可能存在生命。在水手2号之前，我们对太阳系的一切了解都来自地面望远镜的观测和对陨石的分析。
这种有限的视角无法揭示我们太阳系的多样性和真实性质。在这个简短的介绍中，我们将讨论美国宇航局和其他太空机构在过去半个世纪的太阳系探索中是如何完成一系列全面的任务的。

原文：

THE SOLAR SYSTEM EXPLORATION PARADIGM

Artist’s concept of the Mariner 2 spacecraft. (NASA/JPL: PIA04594)

It is our spacecraft missions that provide the opportunity to get up close andpersonal with many bodies in the solar system. Mariner 2 was just the first robotic space probe to conduct a successful planetary encounter, the first step in a long journey. The scientific instruments on board were two radiometers(microwave and infrared), a micrometeorite sensor, a solar-plasma sensor, a charged-particle sensor, and a magnetometer. These instruments measured the temperature distribution on the surface of Venus, made basic measurements of Venus’s atmosphere, discovered the solar wind, and determined that Venus, unlike Earth, has no intrinsic magnetic field.This powerful set of observations fueled our fascination with our cosmic neighborhood and our desire to learn more.
Since Mariner 2, in exploring any particular object, solar system exploration has followed a general paradigm of “flyby, orbit, land, rove, and returnsamples.” A complete campaign may not be performed for each object in the solar system, since not all of our scientific questions can be studied at all objects, and there are difficult technological challenges and financial hurdles to overcome for some types of missions and certain destinations. Moreover, a healthy program of solar system exploration requires a balance between detailed investigations of a particular target and broader reconnaissance of a variety of similar targets.

翻译：

太阳系探索范式

正是我们的太空船任务提供了与太阳系中许多天体近距离接触的机会。 水手2号只是第一个成功地进行行星相遇的机器人太空探测器，这是长途旅行的第一步。 船上的科学仪器有两个辐射计（微波和红外线）、一个微陨石传感器、一个太阳等离子体传感器、一个带电粒子传感器和一个磁强计。 这些仪器测量了金星表面的温度分布，对金星的大气进行了基本测量，发现了太阳风，并确定了金星与地球不同，没有内在磁场。这组强大的观测结果激发了我们对宇宙邻居的迷恋，以及我们想了解更多信息的愿望。
自水手2号以来，在探索任何特定物体时，太阳系探索遵循了“飞越、轨道、登陆、漫游和返回样本”的一般模式不可能对太阳系中的每一个物体都进行完整的运动，因为我们不能对所有物体研究所有的科学问题，而且对于某些类型的飞行任务和某些目的地来说，还有困难的技术挑战和财政障碍需要克服。此外，一个健康的太阳系探索计划需要在对特定目标的详细调查和对各种类似目标的广泛侦察之间取得平衡。

原文：

FLYBY MISSIONS

Flyby missions are designed to obtain the most basic information on their target bodies. Early flyby missions also enabled space agencies to learn to fly between planets. This early trek into the solar system was accomplished with flybys to each planet in our local neighborhood.

MISSIONS THAT ORBIT

Beyond flybys, the next most sophisticated type of mission aimed to get a spacecraft into orbit around a solar system object. Data from flyby missions were essential to prioritizing which objects to orbit. High-resolution data from an orbiter mission are essential to planning for a future lander or rover mission.

LANDER AND ROVER MISSIONS

Lander and rover missions enable scientists to acquire “ground truth,” measurements so necessary to fully interpret data from orbital missions. The successful landings of the 1-metric-ton2 Curiosity rover on Mars and the Rosetta mission’s Philae probe on comet 67P/Churyumov–Gerasimenko clearly show the ability of our space agencies to explore our solar system at a new level of intensity. Steps like these will allow humans to go beyond this planet and out into the solar system once again.

SAMPLE RETURN

A self-portrait of NASA’s Curiosity rover taken at the rover’s location in Gale Crater on Sol 2082 (15 June 2018). (NASA/JPL-Caltech/MSSS: PIA 22486)

Sample return provides scientists with essential data to understand the geological history of a body. Up to the present, space agencies have collected samples from several solar system bodies, as well as samples of the solar wind. The Apollo program in the late 1960s and early 1970s brought back over 850 pounds of Moon rocks, soils, and regolith. These materials are still being analyzed and yielding significant scientific results. It is also important to note that many of the meteorites that have fallen on Earth can now be identified with specific solar system bodies such as the Moon, Mars, and Vesta. The comet 81P/Wild (Wild 2) and the asteroid 25143 Itokawa were visited by robotic spacecraft from NASA and the Japan Aerospace Exploration Agency (JAXA), respectively. Both missions returned samples to Earth.
翻译：

飞越任务

飞越任务旨在获取目标天体的最基本信息。早期的飞越任务也使太空机构学会了在行星之间飞行。这次进入太阳系的早期徒步旅行是通过飞越我们附近的每颗行星完成的。

在轨飞行任务

除了近距离飞越，下一个最复杂类型的任务旨在使航天器进入围绕太阳系物体的轨道。来自飞越任务的数据对于确定哪些物体进入轨道的优先顺序至关重要。来自轨道飞行器任务的高分辨率数据对于计划未来的着陆器或漫游者任务至关重要。

登陆和漫游任务

着陆器和漫游者任务使科学家能够获得“地面真相”，这是完全解释轨道任务数据所必需的测量。 1米吨重2的好奇号探测车成功降落在火星上，罗塞塔任务的菲莱探测器成功降落在67P/Churyumov-Gerasimenko彗星上，这清楚地表明了我们的太空机构以新的强度探索太阳系的能力。 像这样的步骤将允许人类走出这个星球，再次进入太阳系。

样品返还

样品返回为科学家提供了了解地质历史的基本数据。 到目前为止，航天机构已经收集了几个太阳系天体的样本，以及太阳风的样本。 20世纪60年代末和70年代初的阿波罗计划带回了850磅的月球岩石、土壤和风土。 这些材料仍在分析中，并产生重要的科学结果。 同样重要的是要注意到，许多落在地球上的陨石现在可以识别出特定的太阳系天体，如月球、火星和灶神星。 81P/Wild彗星（Wild 2）和小行星25143 Itokawa分别被美国宇航局和日本航空航天勘探局（JAXA）的机器人航天器访问。 两次任务都向地球返回了样本。
原文：

THE NEXT 50 YEARS

Our robotic solar system explorers have gathered data to help us understand how the planets formed; what triggered different evolutionary paths among the planets; what processes are active; and how Earth formed, evolved, and became habitable. To search for evidence of life beyond Earth, we have used these data to map zones of habitability, study the chemistry of unfamiliar worlds, and reveal the processes that lead to conditions necessary for life.
New technologies will enable space agencies to develop and execute an astounding range of more complicated and challenging missions. We are at the leading edge of a journey of exploration that will yield a profound new understanding of the solar system as our home. NASA is building a Space Launch System (SLS) for human exploration, but its use is also being considered for some deep space robotic missions. The SLS will be more powerful than the Saturn V. If it is used for planetary missions to the outer solar system, direct trajectories rather than inner-solar-system gravity-assist maneuvers would be possible, cutting transit time, typically, by one-third. This launch approach alone would open the outer solar system to a significantly increased rate of missions and discoveries.
Robotic exploration not only yields knowledge of the solar system; it also will enable the expansion of humanity beyond low-Earth orbit. By studying and characterizing planetary environments beyond Earth and identifying possible resources, planetary scientists will enable safe and effective human missions into space. Scientific precursor missions to the Moon enabled the Apollo landings and have made significant progress toward enabling human missions to Mars within the next 50 years. A single-planet species may not long survive. It is our destiny to move off this planet and into the solar system. We are developing the capability to do it.

翻译：

未来50年

我们的机器人太阳系探险家收集了数据，帮助我们了解行星是如何形成的；是什么触发了行星之间不同的进化路径；什么过程是活跃的；以及地球是如何形成、进化和变得宜居的。 为了寻找地球以外生命的证据，我们利用这些数据绘制了可居住区域的地图，研究了陌生世界的化学性质，并揭示了导致生命必要条件的过程。
新技术将使航天机构能够开发和执行一系列更复杂和更具挑战性的任务。 我们正处于探索之旅的前沿，这将对太阳系作为我们的家园产生深刻的新理解。 美国宇航局正在为人类探索建造一个太空发射系统（SLS），但它也被考虑用于一些深空机器人任务。 SLS将比土星V更强大。如果它被用于向外太阳系执行行星任务，那么直接轨迹而不是太阳系内部重力辅助机动将是可能的，通常将渡越时间缩短三分之一。 单是这种发射方法，就可以使外部太阳系的任务和发现速度大大提高。
机器人探索不仅产生了太阳系的知识，它还将使人类能够扩展到近地轨道之外。 通过研究和描述地球以外的行星环境并确定可能的资源，行星科学家将使人类能够安全有效地进入太空。 对月球的科学先期任务使阿波罗登月成功，并在未来50年内实现人类对火星的任务方面取得了重大进展。 单个行星的物种可能不会存活太久。 我们的命运就是离开这个星球进入太阳系。 我们正在发展这样做的能力。