美国“火星大气与挥发演化”探测器奔赴火星

2013年11月18日,美国“火星大气与挥发演化（MAVEN）”探测器搭乘“宇宙神v型”火箭发射升空,它将以前所未有的精度研究火星的上层大气。     

星际载人航行的动力之源——核火箭发动机研制“起伏”史

2010年,奥巴马将美国载人航天计划的指挥棒指向了火星。已经在档案馆中沉睡了40年的一个伟大设计——核火箭发动机,又看到了重生的希望。在半个多世纪前的载人航天黄金时代,它因人类的火星远征而生,又随着时代潮流的转向而归于沉寂。核火箭发动机的命运就是这样的起伏跌宕。     

15天，遨游太空

2013年6月11日17时38分。在地动山摇的轰鸣声中,神舟十号飞船在长征二号F遥十火箭托举下腾空而起,并准确进入预定轨道,进而开启了神十飞行乘组航天员聂海胜、张晓光和王亚平为期十五天的太空生活。     

发射短讯

<正>美国空军成功发射WGS-6卫星据Nasaspaceflight网站消息,2013年8月7日,美国东部时间(EDT)20点29分,美国空军用德尔它-4火箭成功发射了全球宽带卫星通信-6(WGS-6)卫星。澳大利亚是第一个加入WGS(Wideband Global Satcom)项目的国家,为WGS-6投资约7亿美元,澳大利亚军方可访问整个WGS星座(计划为10颗卫星,另外4颗正在建造,打算在     

火箭返回制导动力着陆段的自适应启动方法

针对重复使用火箭垂直返回着陆问题,提出了一种燃料最优的动力着陆段自适应启动方法。首先,将燃料最优启动点对应的动力着陆轨迹的推力剖面和攻角剖面描述为解析的形式,该解析形式中攻角剖面由状态量唯一确定,推力剖面仅含一个待定参数。随后,通过预测具有上述解析剖面形式的轨迹判断是否启动动力着陆。计算中引入松弛终端位置约束的策略求解推力剖面待定参数,由终端位置约束判断是否满足燃料最优启动条件。上述策略将燃料最优启动条件的判断问题简化为单一变量求解问题,实现了该问题的快速求解。仿真结果表明,该方法得到的启动点与数值优化方法得到的燃料最优启动点接近,且求解过程稳定、计算效率高。     

25tf膨胀循环氢氧发动机研制进展

25 tf膨胀循环氢氧发动机是针对我国重型运载火箭三级主动力需求研制的液体火箭发动机,也可应用于未来其他航天器的上面级。该发动机采用闭式膨胀循环方式,具备高可靠、高比冲、大范围变推力以及多次点火等能力。发动机已通过推力室挤压热试验、氢涡轮泵介质试验等子系统试验验证了各项关键技术及组合件设计方案,发动机的整机方案实现已不...     

Transient simulation of regression rate on thrust regulation process in hybrid rocket motor

The main goal of this paper is to study the characteristics of regression rate of solid grain during thrust regulation process. For this purpose, an unsteady numerical model of regression rate is established. Gas–solid coupling is considered between the solid grain surface and combustion gas.Dynamic mesh is used to simulate the regression process of the solid fuel surface. Based on this model, numerical simulations on a H2O2/HTPB(hydroxyl-terminated polybutadiene) hybrid motor have been performed in the flow control process. The simulation results show that under the step change of the oxidizer mass flow rate condition, the regression rate cannot reach a stable value instantly because the flow field requires a short time period to adjust. The regression rate increases with the linear gain of oxidizer mass flow rate, and has a higher slope than the relative inlet function of oxidizer flow rate. A shorter regulation time can cause a higher regression rate during regulation process. The results also show that transient calculation can better simulate the instantaneous regression rate in the operation process.     

Storage life of silicone rubber sealing ring used in solid rocket motor

It is urgent to carry out detailed research on storage performance of rubber sealing ring to get the criterion for its storage life. This paper acquires material ageing regularity by theoretical analysis and experimental confirmation. On this condition, failure mode and failure criterion of typical sealing structure is studied, and the failure mechanism is found. Thus by analyzing the stress distribution, the relationship between ageing state and sealing condition is established. Rationalization proposal is put forward and storage life of sealing ring is evaluated. The research mentionedabove has special reference to the design of sealing structures and can provide reference for prolonging their service life.     

“心经”“妙法”铸金牌——航天推进技术研究院研制高质量火箭发动机纪实

神舟九号任务发动机的研制,是在充分继承已有成熟技术基础上进行的。开展可靠性增长设计和适应性改进,既要载人,又要交会对接,是一个需要运用合理科学的可靠性试验方法。经过改进-试验-再改进-再试验的反复过程,打造出质量过硬的高可靠性发动机,具有前所未有的极大难度。     

路漫漫其修远兮,吾将上下而求索——品牌专家孙雷谈创新公关传播创建卓越品牌

编前语睿符品牌传播机构创始人兼总裁,品牌专家,资深公关人睿符品牌传播机构(revo),作为国内一流品牌传播机构,先后被权威机构授予"本土公关潜力榜单20强"、"中国网络广告50强"等荣誉称号,是国内为数不多同时跻身公关、广告、互动领域前