楼主: jingyan66

[专题] 美国星际探测器的最新进展、规划:New Frontiers 4选择泰坦直升机项目

 楼主| jingyan66 发表于 2009-1-29 16:19 | 显示全部楼层


本帖最后由 jingyan66 于 2009-4-14 18:41 编辑

Mars Rover's Unexpected Behavior Puzzles NASA

By Tariq Malik
Senior Editor
posted: 28 January 2009
5:49 pm ET

NASA engineers are scratching their heads over some unexpected behavior from the long-lived Spirit rover, which began its sixth year exploring Mars this month.

Spirit failed to report in to engineers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., last weekend, prompting a series of diagnostic tests this week to hunt the glitch's source. The aging Mars rover did not beam home a record of its weekend activities and, more puzzlingly, apparently failed to even record any of its actions on Sunday, mission managers said.

"We don't have a good explanation yet for the way Spirit has been acting for the past few days," said NASA's Sharon Laubach, who leads the JPL team that that writes and checks commands for the rover and its robotic twin Opportunity. "Our next steps will be diagnostic activities."

Sunday marked Spirit's 1,800th Martian day, or sol, exploring a region known as "Home Plate" in the planet's expansive Gusev Crater.

Spirit and its twin Opportunity were initially expected to spend just 90 days exploring the Martian surface when they landed in succession more than five years ago this month. Opportunity is currently headed for the monster crater Endeavour on the other side of Mars.

On Sunday, Spirit apparently received commands to drive to its next waypoint, but failed to move an inch, mission managers said.

While that glitch can have any number of causes, such as Spirit not properly perceiving it was ready to drive, the rover's failure to record its daily work in its non-volatile computer memory is perplexing, they added.

By Monday, Spirit's mission controllers decided to tell the rover to find the sun with its camera on Tuesday to determine its location on Mars. Early yesterday, the rover beamed back that it had tried to follow the instructions of its human handlers, but couldn't find the sun.

NASA engineers believe Spirit's woes may be due to a transitory cause, such as a high-energy cosmic ray hitting the rover's electronics. On Tuesday, the rover's non-volatile memory appeared to be working fine, mission managers said.

The rovers Spirit and Opportunity have lasted more than 20 times their initial three-month mission plan, with each suffering from aches and pains associated with their longevity.

Spirit initially bounced back from a worrying computer glitch early in its mission and has since survived frigid winters on Mars and scaled a nearby hill. Both rovers have expanded scientists' knowledge of the history of liquid water on Mars during their respective missions.

While puzzling, Spirit's new glitches don't appear to be a serious concern at present, according to NASA's rover mission chief John Callas.

"Right now, Spirit is under normal sequence control, reporting good health and responsive to commands from the ground," he added.
 楼主| jingyan66 发表于 2009-1-29 16:20 | 显示全部楼层


Mars Rover Team Diagnosing Unexpected Behavior

January 28, 2009

CORRECTION: In paragraph 3--Early Tuesday, Spirit reported that it had followed the commands, and in fact had located the sun, but not in its expected location.

Mars Exploration Rover Mission Status Report

PASADENA, Calif. - The team operating NASA's Mars Exploration Rover Spirit plans diagnostic tests this week after Spirit did not report some of its weekend activities, including a request to determine its orientation after an incomplete drive.

On Sunday, during the 1,800th Martian day, or sol, of what was initially planned as a 90-sol mission on Mars, information radioed from Spirit indicated the rover had received its driving commands for the day but had not moved. That can happen for many reasons, including the rover properly sensing that it is not ready to drive. However, other behavior on Sol 1800 was even more unusual: Spirit apparently did not record the day's main activities into the non-volatile memory, the part of its memory that persists even when power is off.

On Monday, Spirit's controllers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., chose to command the rover on Tuesday, Sol 1802, to find the sun with its camera in order to precisely determine its orientation. Not knowing its orientation could have been one possible explanation for Spirit not doing its weekend drive. Early Tuesday, Spirit reported that it had followed the commands, and in fact had located the sun, but not in its expected location.

"We don't have a good explanation yet for the way Spirit has been acting for the past few days," said JPL's Sharon Laubach, chief of the team that writes and checks commands for the rovers. "Our next steps will be diagnostic activities."

Among other possible causes, the team is considering a hypothesis of transitory effects from cosmic rays hitting electronics. On Tuesday, Spirit apparently used its non-volatile memory properly.

Despite the rover's unexplained behavior, Mars Exploration Rovers' Project Manager John Callas of JPL said Wednesday, “Right now, Spirit is under normal sequence control, reporting good health and responsive to commands from the ground."

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Exploration Rover project for the NASA Science Mission Directorate, Washington. Spirit and its twin, Opportunity, landed on Mars in January 2004 and have operated 20 times longer than their original prime missions.
 楼主| jingyan66 发表于 2009-2-11 19:31 | 显示全部楼层





  连接漫游者及其“总部”的绳索可以卷绕,允许漫游者探索对未系绳机器人——例如宇航局的“机遇”号和“勇气”号火星车——来说太过陡峭而无法穿过的区域。宇航局位于加州帕萨迪纳喷气推进实验室的工程师伊萨·内斯纳斯(Issa Nesnas)说:“我们的目标是探测月球和火星上深度较大且陡峭的陨坑。”除此之外,Axel也可利用漂浮在土星卫星——土卫六“泰坦”大气层中的气球下降到目标区域。



  明尼阿波利斯明尼苏达州大学机械工程师尼克斯·帕帕尼克洛普罗斯(Nikos Papanikolopoulos)表示:“人们正在寻找更小并且能够征服众多复杂恶劣地形的系统。”帕帕尼克洛普罗斯领导的研究小组正在研发一种类似的线轴形机器人,名为“Scout”。与Axel有所不同的是,Scout没有系绳,致使倾斜角度被限制在45度以下,具体倾斜角度取决于地形。帕帕尼克洛普罗斯指出,Scout也拥有自身优势,它的重量不到半公斤,长度也只有11厘米,这就允许未来执行任务时进行大规模部署。目前,他的小组正在研制一种最多可容纳10个Scout并为其提供能量的围栏。除了执行地外任务外,军队和应急反应部门也可在地球上使用这种机器人。
 楼主| jingyan66 发表于 2009-2-12 08:48 | 显示全部楼层
Mars Mission Has Some Seeing Red

NASA's Ambitious New Rover Is Too Costly, Critics Say

By Joel Achenbach
Washington Post Staff Writer
Wednesday, February 11, 2009; Page A01

PASADENA, Calif. -- In a "clean room" in Building 150 of NASA's Jet Propulsion Laboratory is something that looks very much like a flying saucer. It's a capsule containing a huge, brawny Mars rover, a Hummer compared with the Mini Coopers that have previously rolled across the Red Planet.

This is the Mars Science Laboratory, the space agency's next big mission to the most Earth-like planet in the solar system. But it's been a magnet for controversy, and a reminder that the robotic exploration of other worlds is never a snap, especially when engineers decide to get ambitious.

The launch has been delayed for two years because of technical glitches. Approved at $1.63 billion, the mission's price tag will be at least $2.2 billion, NASA now estimates. Critics say the cost has really quadrupled since the project was first dreamed up. What no one can doubt is that ambitious missions tend to become costly ones, which jangles the nerves of officials who know how easy it is for a Mars mission to go bust.

Alan Stern, a planetary scientist and former NASA associate administrator for science missions, charged in a New York Times op-ed column last year that the cost overruns of the Mars Science Laboratory are a sign of a "cancer" of spending profligacy that is overtaking the space agency. Stern, now a private consultant, argues that the new rover is too ambitious, with too many new technologies in play, making a cost overrun all but inevitable.

"It's not just that it's a bigger rover. It's also an entirely new kind of landing system. It's also that it's nuclear-powered. It's also that it's carrying multiple instruments far beyond what's ever been done," Stern said in an interview. "We need to go to a strategy where we can access Mars frequently and take advantage of what we've already invented."

NASA officials acknowledge that they are pushing the boundaries of what's possible in Mars exploration. But they say it makes no sense to do the same things over and over again with modest changes.

The new rover, weighing 1,875 pounds, is more than twice as heavy as either Spirit or Opportunity, the remarkably durable rovers that have been sniffing around Mars for the past five years on a mission originally designed to last just 90 days. Those rovers have six instruments each; the new rover has 10, including detectors for organic compounds. The old rovers could reach out, scratch the Martian surface and try to get a sense of things, but the new rover can retrieve a sample and put it in various analytic chambers. Earlier rovers were solar powered, but this one has a nuclear power source that will allow it to operate day and night.

The new rover is more rugged, capable of navigating much trickier terrain. It can operate at higher latitudes with harsher climates. It has its own meteorology station. It has a color camera that shoots video. It can do almost everything but make espresso.

"We need a larger support structure. We need a more capable arm. We need to be able to look at not just the geology but much more the chemistry, much more the organic elements. We have to have a more capable rover," said Jim Green, director of NASA's planetary science division.

He acknowledged that the cost overruns will put a crimp in the planetary science budget, which is running at about $1.3 billion a year. The Mars program specifically will feel the effects, and there will have to be cuts or delays in the next rover mission, scheduled for 2016, he said. But he added that the Mars Science Laboratory will be worth it.

Because it's such a large rover, engineers had to invent a new landing technique, called a sky crane. The rover also needed dozens of motors and gearboxes to accomplish the many tasks outlined by scientific investigators. It was the iffy performance of those motors and gearboxes in tests that forced NASA to pull the plug on the mission's scheduled 2009 launch.

Richard Cook, the project manager, said that in calculating the cost and the amount of time necessary for designing the mission, "we didn't extrapolate how much more complex it was" than the Spirit and Opportunity mission.
 楼主| jingyan66 发表于 2009-2-13 08:00 | 显示全部楼层
Mars Mission Has Some Seeing Red

NASA's Ambitious New Rover Is Too Costly, Critics Say

By Joel Achenbach
Washington Post Staff Writer
Wednesday, February 11, 2009; Page A01

PASADENA, Cali ...
jingyan66 发表于 2009-2-12 08:48



  撰文/乔治·马瑟(George Musser)

  环球科学报道 2008 年10月, 美国航空航天局(NASA) 宣布, 计划于今年秋天发射升空的汽车大小的火星漫游车——火星科学实验室(Mars Science Laboratory,缩写为MSL),已经从价值15 亿美元变成了价值20 亿美元。而在这一计划最初构想时,预计任务花费仅有6.5 亿美元。更令人瞠目结舌的是,号称造价10 亿美元的哈勃空间望远镜继任者——詹姆斯·韦布空间望远镜(James Webb Space Telescope,缩写为JWST)已经花掉了45 亿美元。这种现象并非只发生在空间探索项目中,任何复杂项目的投资都会大大超过预算。不过专家说,在节约研究经费的问题上,研究机构应该、也必须做得更好。


  美国密歇根大学的苏希尔·K·阿特雷亚(Sushil K. Atreya) 说:“ 我们必须接受科研会存在一些成本超支的事实,但我相信如果换一种管理方式,许多成本超支是可以避免的。”他是火星科学实验室研究小组成员,也是美国国家研究委员会(National Research Council,缩写为NRC)去年评估NASA 行星探测项目的评审小组的成员之一。

  评审小组的评估结果十分悲观。受制于持续增长的花费以及不断缩水的预算,NASA 已经不得不推迟甚至取消许多研究项目。一些人担心美国国会今后不会再批准一些耗资巨大的项目,比如将火星岩石带回地球进行分析——这是科学家认为能够确定火星是否曾有生命的唯一办法。艾伦·斯特恩(Alan Stern)说:“由于无视成本控制问题,我现在对火星采样返回能否实现持悲观态度。”斯特恩曾经担任NASA 科学事务副局长,2008年3 月因不满NASA 对火星科学实验室超支问题的处理而愤然辞职。

  看起来NASA 的管理层并非没有意识到超支问题。每个项目都要经过严格公正的评估,并且划拨预算的1/3 左右作为储备金,以供计划外支出。但这些措施根本不足以控制超支。航天飞机及空间站前高级主管、美国得克萨斯大学奥斯汀分校的洪堡·曼德尔(Humbolt Mandell) 说:“ 在一个几乎完全由工程师和科学家掌管的机构里,技术永远比财政更重要。”项目提案之间的竞争也加剧了这种倾向:为了得到资金投入,这些项目不得不做出不可能实现的承诺。

  许多专家坚持NASA 应该在技术开发方面投入更多资金。NASA 曾有一个独立的计划来研制火箭、供电和通讯系统,方便今后的科学任务直接使用这些系统——也能更容易地给这些科学任务“标价”。现在该计划已经取消,一些科学家争辩说,火星科学实验室成了取消该计划的受害者。“我认为所有的花费都被大大低估了,因为他们缺少足够的有用信息,过去在技术方面的投入也远远不够,”NRC评审小组联席主席、华盛顿卡内基研究所的韦斯利·亨特里斯(Wesley Huntress)总结说。


  美国密歇根大学的伦纳德·菲斯克(Lennard Fisk) 刚刚卸任NRC 空间研究委员会主席,他认为,为了填补财政缺口,NASA 总部还应该储备一些资金,数额或许应该达到科学预算总额的5%。否则一旦项目遇到资金短缺,NASA 只有两种选择:一是取消该项目,二是挪用其他项目的资金。

  两种选择都不明智:如果要恢复被取消的项目,一切就必须从头再来,可能会更加昂贵;资金被挪用的项目则会打乱计划,最终也可能要超出预算。不过斯特恩认为,就算当初采用了上述措施,火星科学实验室也难逃超支的命运。他说,最初对项目总花费的评估根本不切实际;当管理层意识到项目即将耗尽资金时,再想缩减计划规模已经不可能了。他坚持认为:“根本没有人为了让项目不至于超支而作过任何让步。”曼德尔主张,在必要的情况下,NASA 应该终止计划,“提前给一个项目设置一条严格的‘生死线’,并坚决执行这一标准,将迫使人们产生危机意识,储存足够的备用金。”

  然而, 有些资金并不在NASA的掌控之中。5 年前,布什总统下令NASA 替换航天飞机,但并未提供相应资金。这迫使NASA“拆东墙补西墙”,暂停了新技术开发,并推迟一些已经万事俱备的项目,这些措施最终都会导致开支增加。如果希望NASA能够最好地利用资金,别对NASA 抱有超过他们财力的、不切实际的预期,会很有帮助。
 楼主| jingyan66 发表于 2009-2-19 19:54 | 显示全部楼层

2009年02月19日   新华网



darklighter 发表于 2009-2-21 23:45 | 显示全部楼层


“黎明”北京时间2月17日20:28以约549 km的最近距离飞越火星。





HaleBoppComet 发表于 2009-2-23 14:41 | 显示全部楼层





hkhtg090201 发表于 2009-2-25 09:16 | 显示全部楼层
    [美国《军事与航空航天电子学》网站2009年2月18日报道]    美国国家航空航天局(NASA)授予极光飞机科学公司及其合作伙伴Vertigo公司一份小企业创新研究(SBIR)第一阶段合同,开发一种自动气球发射器,用于火星表面的工作。激光公司设想了一种紧凑的、轻重量的系统,该系统将可以被装载在未来的火星登陆车上,通过小型天线车辆扩大任务范围。这种系统可以实现当前火星任务难以完成的大气采样和视频数据获取工作。
cmj9808 发表于 2009-2-25 20:19 | 显示全部楼层
Shielded Mars Balloon Launcher
hkhtg090201 发表于 2009-2-25 21:42 | 显示全部楼层
本帖最后由 hkhtg090201 于 2009-2-25 21:44 编辑

cmj9808 发表于 2009-2-26 12:40 | 显示全部楼层
hkhtg090201 发表于 2009-2-25 21:42

 楼主| jingyan66 发表于 2009-3-6 09:01 | 显示全部楼层


本帖最后由 jingyan66 于 2009-3-6 10:52 编辑

Mars Orbiter Needs Risky Computer Reboot

By SPACE.com staff
posted: 05 March 2009
09:05 am ET

NASA's Mars Odyssey orbiter, which has been circling the red planet for nearly eight years, needs a risky reboot to address a long-known, potential vulnerability in its memory system.

The Odyssey team plans to perform the operation next week.

The chief concern about the potential memory vulnerability stems from the length of time that the spacecraft has been exposed to the accumulated effects of the space radiation environment since the last reboot, which occurred on Oct. 31, 2003.

As an additional benefit, the cold-reboot procedure will demonstrate whether Odyssey's onboard backup systems will be available should they ever be required.

"We have lost no functionality, but there would be advantages to knowing whether the B side [backup system] is available," said Odyssey Mission Manager Gaylon McSmith of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We have developed a careful plan for attempting to determine that."

NASA also recently revived its Mars Reconnaissance Orbiter after a glitch sent it into its protective safe mode last week.

In all the years since its April 7, 2001, launch, Odyssey has not needed to use its set of spare components. The spares are called the spacecraft's "B side," which includes an identical set of a computer processor, navigation sensors, relay radio and other subsystems. To use any of them, Odyssey would have to shift to all of them at once from its primary set of components, called the "A side."

On March 21, 2007, the B side spare of an electronic component for managing the distribution of power, called the high-efficiency power supply, became inoperable. If it is permanently disabled, then none of the B side is available for use. Engineers have investigated the inoperability of the power supply and that the component can probably be made to work properly again by rebooting the orbiter's computer, although the memory-vulnerability issue that is the current concern is not directly related to the March 2007 event that affected the power supply.

Odyssey is in the third two-year extension of its mission at Mars.

Some A side components, such as the UHF radio used for communications with spacecraft on the surface of Mars, have worked as long as they were designed to last.

In addition to its own major scientific discoveries and continuing studies of the planet, the Odyssey mission has played important roles in supporting the missions of the Mars rovers Spirit and Opportunity and the Phoenix Mars Lander.
hkhtg090201 发表于 2009-3-6 10:26 | 显示全部楼层
calendfans 发表于 2009-3-8 16:08 | 显示全部楼层
2009年03月08日 08:10  新浪科技
  新浪科技讯 北京时间3月8日消息,据英国《新科学家》杂志网站报道,美国宇航局(NASA)目前正在制定一项新的计划,拟于2016年向火星发射一枚新的探测器。该探测器的主要任务是在火星上寻找甲烷。科学家们认为,如果最终能证实火星上的确存在甲烷,那么这颗星体就很可能存在生命。








cmj9808 发表于 2009-3-9 01:33 | 显示全部楼层
NASA下一个20年的火星探索计划图,2016年发射的应该是MSO(Mars Science Orbiter)
ScreenHunter_03 Mar[1]. 03 23.03.jpg
 楼主| jingyan66 发表于 2009-3-10 09:11 | 显示全部楼层

“勇气”号火星探索遇到障碍 土堆挡住去路











 楼主| jingyan66 发表于 2009-3-11 08:56 | 显示全部楼层
Mars Orbiter Needs Risky Computer Reboot

By SPACE.com staff
posted: 05 March 2009
09:05 am ET

NASA's Mars Odyssey orbiter, which has been circling the red planet for nearly eight years, nee ...
jingyan66 发表于 2009-3-6 09:01


NASA postpones Mars Odyssey reboot


PASADENA, Calif. – NASA has postponed a risky move to restart the computer on the Mars Odyssey spacecraft.

Scientists wanted to reboot the computer because they're worried that its memory may have been corrupted from years of exposure to space radiation. The spacecraft has been orbiting Mars since 2001.

They planned to restart the computer Tuesday until engineers noticed a spike in temperature on the craft's navigation camera.

Mission managers at NASA's Jet Propulsion Laboratory in California delayed the reboot until they figure out why the temperature went up. A new date has not been set.
hkhtg090201 发表于 2009-3-12 10:45 | 显示全部楼层
Odyssey Spacecraft Reboots Successfully
March 12th, 2009

PASADENA, Calif., (NASA) — NASA’s Mars Odyssey orbiter properly followed commands today to shut down and restart, a strategy by its engineers to clear any memory flaws accumulated in more than five years since Odyssey’s last reboot.

The procedure also restored Odyssey’s onboard set of backup systems, called the spacecraft’s “B side,” allowing its use in the future when necessary.

“For nearly two years, we have not known for certain whether the backup systems would be usable, so this successful reboot has allowed us to ascertain their health and availability for future use,” said Odyssey Project Manager Philip Varghese of NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

Odyssey has been orbiting Mars since 2001 and has never switched from its primary set of components, the “A side,” to the backup set, which includes an identical computer processor, navigation sensors, relay radio and other components. In March 2006, the B-side spare of a component for managing the distribution of power became inoperable. Analysis by engineers identified a possibility that rebooting Odyssey might restore that component, which proved to be a side benefit of today’s procedure to refresh onboard memory.

The Odyssey team began a series of steps after the reboot to carefully return the spacecraft to full functioning over the next few days. Following that path, the science instruments will be back to studying Mars by next week.

An unexpected rise in temperature of the star camera in Odyssey’s navigation system on March 9 had prompted a postponement of the rebooting originally scheduled for the next day. Engineers identified the cause as a heater circuit that was temporarily stuck “on.” The circuit was turned off before today’s reboot.

JPL, a division of the California Institute of Technology, Pasadena, manages Mars Odyssey for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

 楼主| jingyan66 发表于 2009-3-14 11:17 | 显示全部楼层


2009年03月14日   新华网  







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