标题: Mars probe set for risky landing 新闻来源:http://news.bbc.co.uk/2/hi/science/nature/7411113.stm An American spacecraft is about to attempt a perilous landing on the surface of Mars. 美国一件太空装备已预备冒险降落於火星表面。 Nasa's Phoenix lander is due to touch down on Monday in the far north of the Red Planet, after a 423-million-mile journey from Earth. 美国太空总署，火凤凰(Phoenix Lander)着陆器预备於星期一着陆於红色火星的极北方， 位於地球的四亿两千三百万英哩远。 The probe is equipped with a robotic arm to dig for water ice thought to be buried beneath the surface. 探测器已装备机械手臂以挖掘深埋於地表冰块。 Scientists say the mission should give the clearest indication yet of whether Mars could once have harboured life. 科学家说这件任务有最清楚不过的指示，就是是否火星存在生命。 The final seven minutes of the probe's ten-month journey is regarded as the riskiest part of the mission. 在最後十个月旅程的最後七分钟是任务中最危险的时刻。 After it enters the top of the Martian atmosphere at nearly 21,000km/h (13,000 mph), the probe must perform a series of manoeuvres to come safely to rest. 在它达到火星最高气压，将近21,000km/h(13,000 mph)，探测器必须执行一连串演练 来执行最後的安置。 It will release a parachute, use pulsed thrusters to slow to a fast walking speed, then come to a halt on three legs. 它将放出降落伞，用脉冲推力器减缓速度，然後静止三只支架脚。 If all goes to plan, the Phoenix lander will reach the surface of Mars at 0053 BST (1953 EDT) on 26 May. 如果执行全部计画，火凤凰着陆器会到达火星的 0053 BST (1953 EDT) 於五月 二十六日。 Nasa controllers will know in about 15 minutes whether the attempt has been successful. NASA的航管员会在约十五分钟後知道是否尝试成功 David Catling from the University of Bristol is a co-investigator on the mission. He said the landing phase would be one of the most exciting and tense parts of the journey, with so much riding on Phoenix's safe descent. 来自英国Bristol大学的David Catling是任务的共同研发者。他说降落表面是控制人员 最刺激最紧张的时刻。 "Everyone involved is on tenterhooks and eager to start this unique exploration," he said. 他说：每个参予的夥伴都是焦虑不安又热切地开始这趟探索。 If all goes to plan, Phoenix will begin a three-month mission to search for ice beneath the Martian surface. 假使计画全开，火凤凰会开始三个月的蒐寻火星表面冰块的任务。 It will use a robotic arm to dig through the protective topsoil layer and lift samples of both soil and ice to its deck for scientific analysis. 它将会用机械手臂挖掘表土层，而且在机体上放上土壤与冰层样本来做科学分析。 Building blocks 建造基地 Dr Tom Pike of Imperial College, London, is part of the British team involved in the project. 伦敦Imperial College的Tom Pike博士是参於计画的英国团队。 "The main goal of the mission is to get below the surface of Mars to where we are almost certain there is water," he told BBC News. 他告诉BBC说：主要任务是撬开火星表面，那些地方几乎确定有水的存在呢！ "The orbiters that are around Mars have already surveyed in great detail the area in which we are landing and we know that there is ice - solid water - 10cm, or maybe even less, below the surface. 火星上的人造卫星已经调查降落处的详细资料而且我们知道那边 有冰！有固态水！有十公分！或许更浅一点。 "Water, of course, is of critical importance because it is one of the building blocks - one of the essential habitats we need - for life." 水！当然是关键性的重点，因为它是建造基地的必需品，那些人类所需的必须要素。 Landing on Mars is a notoriously tricky business. Of the 11 missions that have tried to land probes on Mars since 1971 - only five have succeeded. 降落在火星是个众所周知的麻烦任务。自从1971年，曾有十一个任务尝试降落火星， 只有五次成功。 Phoenix is an apt name for the current mission, as it rose from the ashes of two previous failures. 火凤凰是贴切现在任务的名称，如同它盛开於两次失败的灰烬上。 In September 1999, the Mars Climate Orbiter spacecraft crashed into the Red Planet following a navigation error caused when technicians mixed up "English" (imperial) and metric units. 於1999年九月，火星气候卫星坠毁於红色火星上，由於操作员混淆了「英制」与 「公制」两种尺寸单位上。 A few months later, another Nasa spacecraft, the Mars Polar Lander (MPL), was lost near the planet's South Pole. 几个月後，另一个NASA航空机－Mars Polar Lander (MPL)「火星极地登陆号」，於火星 南极失踪。 Phoenix uses hardware from an identical twin of MPL, the Mars Surveyor 2001 Lander, which was cancelled following the two consecutive failures. 火凤凰使用的硬体是双胞胎，两套一样的系统。另一台航空机 Mars Surveyor 2001 Lander 就是因为两个连续的系统错误而取消。 The probe was launched on 4 August 2007 on a Delta II rocket from Cape Canaveral Air Force Station in Florida. 探测器发射於2007年八月四号，配载於 Delta II 火箭於 Cape Canaveral 佛罗里达空军 基地。 -- Peter Peng aka sinsun 翻译 原文为BBC所有，翻译为sinsun所译 -- ※ 编辑: cinson 来自: 219.84.86.97 (05/26 15:11)