期待 2012/08/06

hbv30year

The Mars Science Laboratory (MSL) is a National Aeronautics and Space Administration (NASA) mission to land and operate a rover named Curiosity on the surface of Mars.[11][12] Currently in transit to Mars, it was launched November 26, 2011, at 10:02 EST[1][3] and is scheduled to land on Mars at Gale Crater on August 6, 2012.[8][9][10] If MSL arrives at Mars, it will attempt a more precise landing than attempted previously and then help assess Mars's habitability. A primary mission objective is to determine whether Mars is or has ever been able to support life, though it will not look for any specific type of life. Rather, it is intended to chemically analyze samples in various ways, including scooping up soil, drill rocks, and with a laser and sensor system.[13] Four major goals are to study Martian geology, study Martian climate, collect data for a human mission, and tackle the aforementioned life questions.[14]

The Curiosity rover is about five times larger than the Spirit or Opportunity Mars Exploration Rovers[15] and carries more than ten times the mass of scientific instruments. MSL was launched by an Atlas V 541 rocket and, after its journey to Mars and then landing, is designed to explore for at least 687 Earth days (1 Martian year) over a range of 5-20 km (3-12 miles).
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太空探索是美国惊人科技和国力的体现, 这个探索车的着陆方式非常特别, 用个类似直升机的东西通过绳子放下, "然后直升机会飞到别的地方..."
让我惊讶的是, 之前发射的机遇号, 居然还在工作, 到时候它将有伴了.

hbv30year

我不是学通讯或天文的, 但现在工作偶然会碰到一些简单的信号处理的问题, 所以对这方面突然有点兴趣. 美国几十年前发射的旅行者一号, 已经离开地球一百多亿英理, 居然还能和地球通信. 前段时间还在接受远程指令, 更换了备用推进器.

NASA's Deep Space Network (DSN) has been in partnership with Voyager 1 and Voyager 2 since 1977, providing daily communications support to the two very distant spacecraft. The excellent partnership continues as the Voyager twin spacecraft explore the regions of our universe near the area where the solar wind meets the interstellar winds – areas never before explored by human-made objects.



Voyager 1 reached a historic milestone in 2004 when it crossed the termination shock where the solar wind slows abruptly from a speed that ranges from 700,000 to 1.5 million mph. Another important milestone was reached on August 15, 2006 when Voyager 1 became 100 AU (Astronomical Unit) from the Sun! One AU is the average distance from Earth to the Sun, 150 million km, or 93 million miles.



In 2007, Voyager 2 crossed the termination shock multiple times at about 84 AU in the southern Solar System, analogous to surfing across an ocean wave that moved in and out. Since Voyager 1 crossed the termination shock at about 94 AU in the northern part of the Solar System, the crossings of the twin Voyager spacecraft showed the asymmetry of the heliosphere, which may be due to an interstellar magnetic field pushing inwards more in the south than the north as described by Voyager Project Scientist and former JPL Director Dr. Ed Stone who leads the team of Principal Investigators. The excellent Project team effort is led by Project Manager Ed Massey, and many have contributed significantly to the outstanding project, as described by a sample of team members’ quotes.



As of September 1, 2008, at the speed of light, it took about 14 hours and 52 minutes for a signal from Voyager 1, which was about 107 AU away from the Sun, to reach one of the giant antennas of the DSN, and about 11 hours and 58 minutes for Voyager 2, which was nearly 87 AU away from the Sun.




Termination shock, heliosphere, heliosheath, heliopause and bow shock.  › larger imageThe above to the right, which depicts the termination shock, heliosphere, heliosheath, heliopause and bow shock, shows Voyager 1 having crossed the termination shock and Voyager 2 before crossing the termination shock. The source of the diagram and information is the Voyager Project. The solar wind is a stream of electrically charged ions ejected from the Sun's atmosphere, which sweeps past all the planets at supersonic speeds. It creates a bubble around the Sun, called the heliosphere, which extends far beyond the orbits of the planets. Inside the heliosphere is a boundary called the termination shock where the speed of the supersonic solar wind is suddenly reduced. The outer boundary of the heliosphere, where the expanding solar wind is balanced by the inward pressure of interstellar matter is called the heliopause. The heliosheath is the region between the termination shock and the heliopause. A bow shock forms as the Sun progresses through the ionized interstellar gas.



Because of the enormous distances and the resultant weak signals from the spacecraft, the large antennas and the very sensitive receivers of the DSN are required to provide the necessary communications capabilities. The DSN is the world's largest and most sensitive spacecraft communications network. It consists of three deep space communications complexes located approximately 120 degrees of longitude apart around the world: at Goldstone, California; near Madrid, Spain; and near Canberra, Australia. This placement permits continuous communication with a spacecraft.



Each deep space communications complex provides capabilities required to perform telemetry data processing, including signal reception and amplification, signal demodulation and decoding, and data extraction. It also provides a capability to send commands generated by the project to the Voyager spacecraft. All DSN complexes are linked to JPL via a world-wide communications network.



The Deep Space Network, the premier network for deep space communications, allows the Voyager spacecraft to continue to send new and unique data from the far reaches of space. Voyager 1 is the farthest spacecraft from the Sun, even beyond the recently discovered Sedna, and Voyager 2 is the second farthest operating spacecraft. As these distances continue to increase, the DSN has implemented new techniques, such as arraying of antenna and combining of weak signals, that will allow continuing excellent support of the Voyager spacecraft.



The thrilling discoveries during Voyager's many years of exploration, including the grand tour of the outer planets, would not have been possible without the sustained exemplary support of the Deep Space Network. The excellent Voyager-DSN partnership continues during the Voyager Interstellar Mission as Voyager 1 and 2 explore the transition region between the heliosphere and interstellar space and are poised to become humanity's first interstellar probes.

hbv30year

It is coming..............

北京时间7月10日消息，根据一项新的研究发现，美国宇航局的“好奇”号火星车在火星表面进行勘察时无需向地下钻探太深，便有可能发现生命存在证据。研究显示“好奇”号只需向地下钻探几英寸，便有可能发现证明火星过去曾有生命存在的复杂有机分子。8月，“好奇”号将在火星表面着陆。




新研究发现“好奇”号的钻头只需向地下钻探4英寸(约合10厘米)，便足以发现构成生命的复杂组件，尤其是在最近因小行星撞击形成的陨坑。美国普渡大学的杰伊-梅罗什等科学家认为生命可能在火星上形成，而后由小行星带到地球。




根据这项新研究，在火星表面进行勘探时，“好奇”号只需向地下钻探很浅的位置便有望发现火星过去曾有生命存在的证据，但前提是这种证据确实存在。研究结果显示火星上存在简单的有机分子。研究论文主执笔人、宇航局戈达德太空飞行中心的亚历山大-巴甫洛夫指出，宇航局在“好奇”号执行探索任务期间发现证明生命存在证据的可能性将超出此前预计。




复杂有机分子是证明火星过去曾有生命存在的一个更强有力证据。这些分子由10个或者更多碳原子构成，与形成生命所需要素——例如构成蛋白质的氨基酸——类似。在地下2到4英寸(约合5到10厘米)，辐射量降低10倍。研究小组报告称，虽然环境仍十分极端，但单个甲醛分子等简单有机分子能够在这一深度幸存。在一些地区，尤其是年轻陨坑，“好奇”号也可能发现复杂的生命构成要素。巴甫洛夫说：“过去的火星登陆器并未发现任何有机物质，这对我们来说是一个挑战。我们知道火星上一定存在有机分子，但我们一直未能在土壤中发现这种分子。



与此前的火星车不同，“好奇”号携带了用于进行岩石和土壤样本收集的设备，样本经处理后送入车载检测室进行分析。它的机械臂装有两个装置，一个用于挖土，制备和传送样本以进行分析，另一个像刷子在火星表面刷动。




“好奇”号的任务是研究火星环境是否有利于微生物生存，同时在岩石中寻找能够证明火星过去曾有生命存在的证据。登陆后，这辆火星车将对着陆点进行评估，确定过去是否拥有或者现在仍拥有适于微生物生存的环境。“好奇”号将在盖尔陨坑一个成层结构的山脉脚下附近着陆。这个山脉的层中含有在水中形成的矿物质。盖尔陨坑底部存在一个冲积扇，与带有水的沉积物形成的地貌类似。












这幅图解展示了“好奇”号的结构、体积、运载火箭、登陆区以及整个着陆过程




“好奇”号还搭载了与此前火星车相比更为先进的科学仪器，科学仪器的重量是此前火星车的10倍。“好奇”号的长度是火星探索漫游者——2003年发射的“机遇”号和“勇气”号的2倍，重量是它们的5倍。“好奇”号的很多设计都继承自它的前辈，包括六轮驱动、摇臂转向悬挂系统以及安装在桅杆上的照相机，用于帮助地球上的科学家选择探索目标和前进路线。




巴甫洛夫表示火星环绕太阳运行，一直受到小流星和行星际尘埃颗粒“轰油炸”，这些物体含有大量有机化合物。随着时间的推移，它们不断在火星表面积聚。“好奇”号又名“火星科学实验室”，是最新并且体积最大的火星车，将于2012年8月登陆火星。这辆火星车并非安装铲子，但装有钻头，用于收集、存储和分析火星地下几英寸的岩石和土壤样本。过去的火星车只能收集较为疏松的表层土壤，由于这些土壤直接暴露在宇宙射线环境下，导致发现有机分子的可能性微乎其微。



巴甫洛夫表示，在对有机分子可能存在于火星地下多大深度进行分析时，此前的研究主要聚焦于宇宙辐射所能抵达的最大深度，大约位于地下1.5米。超过这一深度，有机分子能够在不遭破坏情况下存在数十亿年。




为了让“好奇”号在地下1到5厘米发现有机分子，科学家将年龄不超过1000万年的年轻陨坑作为探测目标。在此前选择探测目标时，科学家主要选择那些样本能够在不遭破坏情况下存在数十亿年的区域。巴甫洛夫说：“如果有机会进行钻探，你绝不希望将大部分时间花在保存状况完好的地带，也一定希望对年轻陨坑进行勘探，原因就在于发现复杂有机分子的可能性更大。也就是说，要让自然为你工作。”







“好奇”号将于8月6日在盖尔陨坑着陆。这个形成于35亿年前的陨坑内是否存在较为年轻的陨坑仍是一个未知数。巴甫洛夫希望他的研究小组的发现至少能够为宇航局在选择钻探区域时提供参考，为未来的火星任务打下良好基础。









汽车大小的“好奇”号火星车，正借助太空起重机在火星表面着陆。这辆火星车将于8月在火星着陆



“好奇”号火星车，红色方框为俄罗斯制造的中子发射装置。登陆之后，“好奇”号将收集火星地下的含水矿物并进行分析

hbv30year

人类对未知世界的探索是非常让人欢欣鼓舞的. 中国现在也是积极的向太空发展, 差距不少, 但比以前是强了许多, 还是让华人很自豪的. 比如神州九号, 娇龙好等.
但是, 看看深海探索号, 好有个参考:
Editor’s note: On March 26, 2012, James Cameron made a record-breaking solo dive to the Earth’s deepest point, successfully piloting the DEEPSEA CHALLENGER nearly 7 seven miles (11 kilometers) to the Challenger Deep in the Mariana Trench. DEEPSEA CHALLENGE is now in its second phase—scientific analysis of the expedition’s findings. Click here for news about the historic dive, an exclusive postdive interview with Cameron, and information about the next phase of the expedition.

“Worry is a good thing when you’re an explorer. It’s when you’re cavalier, when you take risk for granted, that’s when you’re gonna get bit.” —James Cameron
Exploration is inherently dangerous. The DEEPSEA CHALLENGE team is cognizant of the risk of traveling to the ocean’s deepest point and does everything possible to mitigate the many hazards. Under the leadership of James Cameron and Ron Allum, each and every member of the team is encouraged, even required, to be explicit about the risks that are simply part of their work. The expedition philosophy follows the thinking that the only way to protect against risk is by anticipating, understanding, and addressing it outright. There is a great deal to be gained if DEEPSEA CHALLENGE is successful, but all members of the expedition acknowledge that lives are at stake and that, as Cameron himself has written, “there are a lot of ways to die.”

Cameron outlines some of these ways, in his own words, below.

IMPLOSION
The obvious one. You’ve miscalculated the design of your sphere. As you approach the bottom, with barely a warning groan, the sphere buckles suddenly. Faster than you can scream, you’re smashed into jam.

PENETRATOR FAILURE
There’s a dead short someplace and one of the pins in your electrical penetrator—the device that feeds power and control signals through the sphere wall—melts, causing the penetrator to fail. The water jet erodes the interior of the penetrator, allowing seawater to blast inside, at 16,000 psi.

FREEZING
If you get stuck on the bottom your weights don’t drop, and it’s a race between your life support running out and freezing to death. But you’ve got 60 hours of scrubber and O2, so freezing wins. Because the water outside is just above 0°C … icewater.

FIRE
Electrical fires can break out among all of the sub’s gadgets, and with O2 pumping into the pilot sphere, fires can grow quickly. Although a fire extinguisher is stored in the sphere, it may not be enough to extinguish a sizable fire.

VIEWPORT FAILURE
You’re looking out the viewport when suddenly you see cracks developing. The cracks quickly web throughout the thick volume of the acrylic, and it starts to give way. Then BANG! The cork pops and the sea hammers in like a supersonic piston.

ADRIFT
Only one ascent weight drops instead of both. So you ascend close to the surface but not all the way. Over the next ten hours a two-knot midwater current takes you 20 miles away, and the surface crew has no idea where you are, because you’re not at the surface.

Three Unexpected Dangers of Deep-Ocean Exploration

The “behind the scenes” information posted on the DEEPSEA CHALLENGE website provides incredible insight into the types of challenges—and logistics—that go into planning and executing an expedition of this size and scope. There are surprises everywhere—things one might never have thought to consider on their own and the planning for which there are few, if any, precedents. The work of the DEEPSEA CHALLENGE is an exercise for mystery- and puzzle-loving minds. Three expedition risks that the DEEPSEA CHALLENGE team has anticipated and addressed that might take nondivers by surprise are listed below.

HYDROTHERMAL VENT-INDUCED MELTDOWN
As first reported in expedition blogger Dr. Joe MacInnis’s March 18 entry, several of the expedition’s members, including the legendary Captain Don Walsh, one of two people ever to have been to the Challenger Deep prior to this expedition, discussed the risks of “flying a research sub too close to a hydrothermal vent,” where they “casually mention[ed]” that the water temperature approached 700 degrees and would melt a sub’s viewport.

SEAFLOOR COMMUNICATIONS CABLE ENTANGLEMENT
Submarine communications cables are cables that traverse the seafloor between land-based stations to extend telecommunication signals across stretches of ocean. Were the sub to become entangled in these cables, it might prevent it from returning to the surface.

HYPOTHERMIA AND HYPERTHERMIA
The DEEPSEA CHALLENGER submersible is a state-of-the-art vehicle—but it is not equipped with a thermostat that can adjust internal temperatures for comfort. The temperature range for a dive borders on the extreme. As the National Geographic expedition website reports, “the temperature will drop from sauna-like at the surface to meat-locker cold at the bottom.” Cameron will dive wearing many layers but the risk of overheating or freezing is significant. In a personal communication to his team, Cameron described a recent experience with heatstroke-like symptoms as he waited inside the sub’s unventilated pilot sphere to be launched into the ocean:

“Hyperthermia early in the dive (and throughout shallow test dives) is a hazard in this vehicle, at least as much as hypothermia late in a deep dive. I found my mental performance slipping after two hours at 102 degrees/100% humidity [while piloting the sub for a test dive]. It doesn’t sound that hot but with zero evaporative cooling available in such a tiny airspace, I’m sure my core temp was going up to match air temp. I got sub internal temp back down to 97 degrees. But by then I was trashed, and had lost several pounds in water.”

hbv30year

In a show of technological wizardry, the robotic explorer Curiosity blazed through the pink skies of Mars, steering itself to a gentle landing inside a giant crater for the most ambitious dig yet into the red planet's past.

Cheers and applause echoed through the NASA Jet Propulsion Laboratory late Sunday after the most high-tech interplanetary rover ever built signaled it had survived a harrowing plunge through the thin Mars atmosphere.

"Touchdown confirmed," said engineer Allen Chen. "We're safe on Mars."

Minutes after the landing signal reached Earth at 10:32 p.m. PT (1:32 a.m. ET), Curiosity beamed back the first black-and-white pictures from inside the crater showing its wheel and its shadow, cast by the afternoon sun.

Members of the Mars Science Laboratory team celebrate at the Jet Propulsion Laboratory after receiving the first few images from the Curiosity rover, in Pasadena, Calif. One of the first images sent from the rover is shown on screen in the background. NASA TV/Reuters
"We landed in a nice flat spot. Beautiful, really beautiful," said engineer Adam Steltzner, who led the team that devised the tricky landing routine.

It was NASA's seventh landing on Earth's neighbour; many other attempts by the U.S. and other countries to zip past, circle or set down on Mars have gone awry.

The arrival was an engineering tour de force, debuting never-before-tried acrobatics packed into "seven minutes of terror" as Curiosity sliced through the Martian atmosphere at 13,000 mph.

In a Hollywood-style finish, cables delicately lowered the rover to the ground at a snail-paced 2 mph. A video camera was set to capture the most dramatic moments — which would give Earthlings their first glimpse of a touchdown on another world.

Celebrations by the mission team were so joyous over the next hour that JPL Director Charles Elachi had to plead for calm in order to hold a post-landing press conference. He compared the team to athletic teams that participate in the Olympics.

"This team came back with the gold," he said.

The extraterrestrial feat injected a much-needed boost to NASA, which is debating whether it can afford another robotic Mars landing this decade. At a budget-busting $2.5 billion, Curiosity is the priciest gamble yet, which scientists hope will pay off with a bonanza of discoveries and pave the way for astronaut landings.

"The wheels of Curiosity have begun to blaze the trail for human footprints on Mars," said NASA chief Charles Bolden.

President Barack Obama lauded the landing in a statement, calling it "an unprecedented feat of technology that will stand as a point of national pride far into the future."

Over the next two years, Curiosity will drive over to a mountain rising from the crater floor, poke into rocks and scoop up rust-tinted soil to see if the region ever had the right environment for microscopic organisms to thrive. It's the latest chapter in the long-running quest to find out whether primitive life arose early in the planet's history.

The voyage to Mars took more than eight months and spanned 352 million miles. The trickiest part of the journey? The landing. Because Curiosity weighs nearly a ton, engineers drummed up a new and more controlled way to set the rover down. The last Mars rovers, twins Spirit and Opportunity, were cocooned in air bags and bounced to a stop in 2004.

Curiosity relied on a series of braking tricks, similar to those used by the space shuttle, a heat shield and a supersonic parachute to slow down as it punched through the atmosphere.

And in a new twist, engineers came up with a way to lower the rover by cable from a hovering rocket-powered backpack. At touchdown, the cords cut and the rocket stage crashed a distance away.

Curiosity equipped with tools, cameras, weather station

The nuclear-powered Curiosity, the size of a small car, is packed with scientific tools, cameras and a weather station. It sports a robotic arm with a power drill, a laser that can zap distant rocks, a chemistry lab to sniff for the chemical building blocks of life and a detector to measure dangerous radiation on the surface.

It also tracked radiation levels during the journey to help NASA better understand the risks astronauts could face on a future manned trip.

Over the next several days, Curiosity was expected to send back the first color pictures. After several weeks of health checkups, the six-wheel rover could take its first short drive and flex its robotic arm.

The landing site near Mars' equator was picked because there are signs of past water everywhere, meeting one of the requirements for life as we know it. Inside Gale Crater is a 3-mile-high mountain, and images from space show the base appears rich in minerals that formed in the presence of water.

Previous trips to Mars have uncovered ice near the Martian north pole and evidence that water once flowed when the planet was wetter and toastier unlike today's harsh, frigid desert environment.

Curiosity's goal: to scour for basic ingredients essential for life including carbon, nitrogen, phosphorous, sulfur and oxygen. It's not equipped to search for living or fossil microorganisms. To get a definitive answer, a future mission needs to fly Martian rocks and soil back to Earth to be examined by powerful laboratories.

The mission comes as NASA retools its Mars exploration strategy. Faced with tough economic times, the space agency pulled out of partnership with the European Space Agency to land a rock-collecting rover in 2018. The Europeans have since teamed with the Russians as NASA decides on a new roadmap.

Despite Mars' reputation as a spacecraft graveyard, humans continue their love affair with the planet, lobbing spacecraft in search of clues about its early history. Out of more than three dozen attempts — flybys, orbiters and landings — by the U.S., Soviet Union, Europe and Japan since the 1960s, more than half have ended disastrously.

One NASA rover that defied expectations is Opportunity, which is still busy wheeling around the rim of a crater in the Martian southern hemisphere eight years later.

© The Canadian Press, 2012