Go homepage(回首页)
Upload pictures (上传图片)
Write articles (发文字帖)

The author:(作者)hpmailer
published in(发表于) 2013/12/1 20:43:19
Chang， third this afternoon will raise cryogenic propellant

Chang the third probe, to be launched on December 2. Xinhua learned today from the Xichang satellite launch Center, the Centre has started at the 29th rocket getting ready for a conventional propellant filling 30th notation, indicating the rocket into the launch sequence. On December 1 the task procedures before entering the shoot in the afternoon hours before the launch, better quality, higher-energy light of cryogenic propellant will be raised.

Task launch area command Deputy Commander Zhao Min on, rocket testing, raise and launch is the Chang-core elements of the third shuttle mission. Assume the long third improved rocket launch on October 31 launch, rocket test facility completes the product recovery, range of equipment testing, initiating the installation work; transferred to 2nd November 9 after launching stations, subsystems tests were completed and four integrated testing work, the current system is fully functional.

Chang third, detector Yu September 12 air approach, in satellite test plant completed has integrated test Qian Assembly and the integrated test, landing players, and visits players Joint Assembly and the test; November 9 to 17th completed has detector raises and the transitions prepared, November 18 go to 2nd, launches station, completed has and rocket butt, and plus electric test, and battery charging, work, currently detector of the indicators completely meet launches requires.

Cryogenic propellant rocket during launch may encounter raises difficult, upper-air wind, night shots, and other factors, is fully prepared and effective prevention.

Xichang satellite launch Center in China's only use of cryogenic propellant launch sites, using cryogenic included liquid hydrogen and liquid oxygen and liquid nitrogen. A low boiling point of liquid nitrogen, liquid nitrogen oxide is strong, easily cause fire and explosion.

"Call more than 400 tons of conventional propellant must be accurate and in place, raise you must drop of fluid does not leak liquid nitrogen and liquid oxygen. In addition, the filling of cryogenic propellant time must sooner or later, one minute will result in volatile early, late and might miss a launch window. Therefore, refueling at low temperature to minus 4.5 points to complete prior to launch. Actions necessary to prevent frostbite and open flames, electrostatic-proof. "Zhao Min said.

Zhao Min, said the Center has formed a set of methods of protection, including site management, ban mobile phones, lighters into filling the field within 50 m; research and development of hydrogen alarms; after entering the Apostille procedure, use explosion-proof power supplies.

World aviation history, there have been cases of upper air wind problems lead to failure. November, December of Xichang in the upper wind-prone stage, giving Chang the third successful launch increased the difficulty of the task. "Center on nearly 40 years of climate data for analysis than on, for 8,000 to 12,000 meters to accurately predict upper-air wind, temperature forecast error of no more than one degree. At the same time, rocket themselves take a lot of design and measures of preventing high altitude wind. Current projections, launch day in good condition, free of thunderstorms and Gale, upper-air wind speed and direction will not launch at risk. "Zhao Min said.

According to another report, this mission boosters and other debris to fall into the provinces of Guizhou, Hunan and Jiangxi province, sparsely populated region, has been making related preparations. (Reporter Wu Yuehui)

(Original title: Chang the third: raise conventional propellant to prevent the disadvantages)

　　嫦娥三号探测器将于12月2日凌晨1时30分发射。记者今天从西昌卫星发射中心了解到，中心已于29日展开火箭常规推进剂加注前的准备工作，30日开始加注，预示火箭进入发射程序。12月1日上午任务将进入射前工作程序，下午发射前数小时，质量更轻、能量更高的低温推进剂也将被加注。

　　任务发射场区指挥部副指挥长赵民介绍，运载火箭测试、加注和发射是本次嫦娥三号发射任务的核心内容。承担发射任务的长征三号乙改进型运载火箭于10月31日运抵发射场，在火箭测试厂房完成了产品恢复、单元仪器测试、火工品安装等工作；11月9日至10日转往2号发射工位后，完成了分系统测试和四次综合测试等工作，目前系统完全正常。

　　嫦娥三号探测器于9月12日空运进场，在卫星测试厂房完成了综合测试前总装及综合测试，着陆器、巡视器联合总装及测试；11月9日至17日完成了探测器加注及转场准备，11月18日转至2号发射工位，完成了与火箭对接、加电测试、电池充电等工作，目前探测器的各项指标完全符合发射要求。

　　针对火箭发射过程中可能遇到的低温推进剂加注难度大、高空风、夜间发射等不利因素，也做好了充分准备和有效防范。

　　西昌卫星发射中心作为我国唯一使用低温推进剂的发射场，使用的低温推进剂包括液氢、液氧和液氮。液氮沸点很低，液氮氧化性强，易引起燃烧和爆炸。

　　“加注400多吨常规推进剂必须准确到位，加注液氮和液氧则必须滴液不漏。此外，加注低温推进剂的时间不能早一分或晚一分，早一分就会造成挥发，晚一分又有可能错过发射窗口。因此，低温燃料加注一直到发射前负4分半钟才能完成。操作中既要防冻伤，又要防明火、静电等。”赵民说。

　　赵民介绍说，中心已形成了一整套防护方法，包括加强现场管理，禁止手机、打火机等进入加注现场50米范围内；研发了氢报警装置；进入加注程序后，一律使用防爆电源等。

　　世界航天史上，曾有过因高空风问题导致失败的案例。11月、12月的西昌处于高空风的多发期，这给嫦娥三号任务的成功发射增加了难度。“中心对近40年的气候资料进行分析比对，对8000米到1.2万米的高空风进行精确预测，气温预报误差不超过一度。同时，火箭自身也采取了很多防止高空风的设计和措施。目前预测，发射当天天气状况良好，无雷雨、无大风，高空风的风速和风向也不会对发射带来危险。”赵民说。

　　另据悉，此次任务助推器等残骸将落入贵州省、湖南省和江西省人烟稀少区域，目前已做好相关准备工作。(记者 吴月辉)

(原标题：嫦娥三号：加注常规推进剂 对不利因素进行防范)

赞