The cost of reaching orbit: Ground-based launch systems

The high cost of launching payloads into orbit - roughly $20,000/kg - continues to deter large-scale exploration and exploitation of space. Ground-based launch systems may radically reduce costs to $200/kg, drastically altering the economics of spaceflight. Low costs will encourage the creation of new markets, including solar-based power satellites and disposal of nuclear waste. The US government should establish a goal of $200/kg by 2020 and provide the resources needed to develop such systems.     

Ensuring an acceptable reliability and safety level for a launch complex

Some key aspects and criteria tasks for ensuring an acceptable reliability and safety level for complex technical systems are discussed in the view of successful operation of a launch complex, at the stage of Launch Vehicle (LV) preparation. The standards and principles of adequate characteristics for launch site core technological systems are defined. The tasks for evaluation the probability of faultless operation for the systems, their reliability a posteriori, and safety barriers formation are described. The model of the pre-launch phase is presented as a random process, in the form of “simple Poisson flow”.     

Human productivity in space and systems costs

Human productivity during assembly operations in-orbit is dependent on limits set by fatigue, metabolic rates, learning, and assembly techniques. In order to quantify these effects, tests were conducted in the NASA MSFC Neutral Buoyancy Simulator, in the NASA KC-135 in parabolic flight, and in space with the EASE program during the Shuttle Atlantis mission 61-B. A separate program attempted to relate productivity to system costs. Because of the surprisingly high productivity which had been demonstrated in orbit, it was shown that assembly operations would have only a small effect on system costs at the present level of launch costs. The results of these continuing studies have been reported in a recent paper(1). They will be briefly summarized here and the results updated to include additional cost elements and to examine the effects of reductions in transportation costs, resulting from advances in technology and from increased demand, on system costs. It is shown that, as launch costs are reduced, the assembly costs could become an increasingly important component of the total system costs.     

The transcost-model for launch vehicle cost estimation and its application to future systems analysis

The first part of the paper describes the structure of the analytical cost estimation model (1982 edition) for launch vehicle development, fabrication and launch operations cost. Especially the new approach for a cost assessment of operations cost including refurbishment (in case of reusable vehicles), direct and indirect operations is presented for discussion and subsequent improvements by introduction of more reference values. The model uses the Man-Year (MY) as cost unit which is independent from inflation and currency exchange rate changes.

The second part of the paper deals with its application to future systems analysis and cost comparison with the example of a potential future European launcher (Post-Ariane-4) with 15 tons LEO payload capability: ten different two-stage launch vehicle concepts (expendable, semi-reusable and fully reusable) with storable and cryogenic propellants are analysed with respect to development cost and cost per launch.

The key problem for a future European launch vehicle is the optimum solution between the (limited) development effort and the desired minimum launch cost. More advanced (partially) reusable systems could provide an essential reduction in cost per launch, require, however, a higher development effort.

In such a case an analytical cost model based on realistic reference data can provide important data for the vehicle concept selection process.     

运载火箭地面测发控设备研制中的“三化”设计

分析目前我国运载火箭地面测发控设备"三化"的现状,简介我国现有的运载火箭地面测发控"三化"标准,提出进一步开展运载火箭地面测发控设备"三化"工作的设想.     

The future of launch vehicles

This article traces the development of satellite launch vehicles from the derivatives of long-range ballistic missiles to the current Ariane and Space Shuttle programmes. Looking to the next generation of launchers, the author outlines current thinking on reusable vehicles, focusing particularly on the British Aerospace/Rolls Royce HOTOL concept.     

The Israeli satellite launch: Capabilities, intentions and implications

The launch of the Israeli satellite Ofeq-1 during September 1988 has significant regional and global implications. These include the proliferation of both surveillance satellites and ballistic missiles, the latter having the potential to deliver conventional, chemical and nuclear warheads to areas situated many hundreds of miles away. This paper addresses both the origins of the Israeli booster technology and the many implications of the satellite launch. It then speculates on their political and arms control consequences. It concludes that in light of the parallelism that has evolved between nuclear and chemical weapons and ballistic missiles, there is an increasing need to develop global and, if appropriate, regional and bilateral strategies to limit missile proliferation and bring the issue to the forefront of international political debate.     

The impact of launch vehicle type and size on development cost

The technical development trend of future launch vehicle systems is towards fully reusable systems, in order to reduce space transportation cost. However, different types of launch vehicles are feasible, as there are

• —winged two-stage systems (WTS)

• —ballistic single-stage vehicles (BSS)

• —ballistic two-stage vehicles (BTS)

The performance of those systems is compared according to the present state of the art as well as the development cost, based on the “TRANSCOST-Model”. The development costs are shown versus launch mass (GLOW) and pay-load for the three types of reusable systems mentioned above.It is shown that performance optimization and cost minimization lead to different results. It is more economic to increase the vehicle size for achieving higher performance, instead of increasing technical complexity.Finally it is described that due to the essentially lower launch cost of reusable vehicles it will be feasible to recover the development cost by an amortization charge on the launch cost. This possibility, however, would allow commercial funding of future launch vehicle developments.     

运载火箭性能计算一体化优化设计系统分析与设计

运载火箭性能计算一体化优化设计系统在运载火箭方案论证设计阶段中有着重要的应用价值。本文在面向对象方法学的指导下，建立了运载火箭性能计算一体化优化设计软件系统的对象模型、动态模型以及功能模型，划分了系统的组成模块，利用Visual studio 6．O和Office2000开发实现了该软件系统。对象技术的应用使得系统具有良好的通用性。该软件系统可以完成不同型号运载火箭和不同优化设计性能要求的仿真优化计算，软件具有较好的稳定性、可重用性和可维护性。     

固体推进剂多失效模式相关的贮存可靠性评估

对丁羧(CTPB)推进剂的自然贮存数据进行分析,采用多失效模式相关的可靠性模型,根据推进剂的抗拉强度变化、燃速变化和密度变化导致推进剂失效以及这3种失效模式之间的相关性,对推进剂的贮存可靠性进行了评估,得到了丁羧推进剂可靠寿命约为10 a的结论。结果表明,考虑失效模式之间的相关性时,丁羧推进剂的贮存可靠度大于假设失效模式相互独立按串联模型计算的贮存可靠度,小于单一失效模式贮存可靠度的最小值,结果更加合理可信。     

基于故障物理的航空电子设备高可靠性评估

传统的基于事后统计的可靠性评估手段已不能满足高可靠性航空电子设备的设计需求。文章提出在产品的设计阶段应用一种基于故障物理的可靠性评估方法,以某型大气数据计算机为研究案例,将环境载荷模拟施加于产品数字模型上,提取应力信息,进行潜在故障机理分析和相应的故障物理模型确认,以及累积损伤分析,最后得到产品的故障前时间以及故障率和可靠度函数。结果表明,该方法与实际可靠性试验结果有较好的近似度。     

基于在轨运行状态的卫星稳定性与可靠性研究

为解决卫星在轨运行故障率较高的问题,文章分析了卫星在轨运行的特点,定义了卫星在轨工作状态及其与系统稳定性变化的关系。研究表明:对在轨运行安全稳定状态进行控制,能使状态保持或向高级跃迁,可提升卫星稳态及可靠性。文章最后提出了提高卫星在轨运行稳定性与可靠性的在轨运行策略与技术方向。     

弹道导弹发射阵地的生存和防护

主要分析了弹道导弹发射阵地可能面临的来自空间和空中的威胁,包括被侦察和被攻击的威胁。提出了提高弹道导弹发射阵地的生存能力和防护能力应配备的电子防护系统,包括发射阵地的战场电磁环境信息监测系统和综合电子干扰系统。     

锤头体弹性振动跨音速气动阻尼系数的确定

通过研究锤头形运载火箭跨音速飞行时，箭体结构的弹性振动与气体运动的耦合效应，描述了用全弹模型的风洞实验和非定常数值计算、确定气动阻尼系数的技术和方法，分别给出了实验和数值模拟的结果，并对结果进行了对比分析。结果表明，在气动阻尼实验中，模拟低阶固有模态的前节点位置是非常重要的，该方法可以作为研究航天飞行器非定常飞动特性的一种方法。     

卫星总体可靠性安全性设计审查

为了确保卫星及其产品不带问题出厂、不带隐患上天,进行系统、全面的卫星可靠性安全性设计专项审查,从卫星总体层面去把握卫星各系统和单机的安全性、可靠性,找出影响卫星安全性和可靠性的问题和薄弱环节,并及时采取有效措施加以改造,对于卫星研制是十分必要和有效的手段。文章基于如何立足卫星总体层面进行可靠性、安全性设计审查提出了一套具体的思路及方法。     

中国重型运载火箭动力系统研究

分析了未来航天发展趋势,指出为实现载人登月和深空探测,发展重型运载火箭,研制大推力火箭发动机势在必行.提出了中国重型运载火箭主动力--_1500吨级液氧煤油发动机和200吨级液氧液氢发动机的总体方案,确定了发动机的主要参数,明确了发动机的关键技术,考虑了发动机的研制条件,进行了发动机研制策划.根据中国的技术水平和经济实...     

运载火箭静电带电理论研究与试验验证

运载火箭在大气中飞行会使箭体、发动机等表面带电,当静电累积达到一定量级并产生静电放电时,可能对箭上电气设备造成灾难性后果。在众多起电原因中,文章重点研究发动机喷流起电和摩擦起电过程,提出这2种起电方式的计算模型,并结合相关静电测量试验,确定这2种起电方式的等效充电电流,定量分析火箭最大静电带电电位,为指导单机设计及系统防护提供参考。     

电磁发射技术的关键问题及其数值模拟

为了分析影响电磁发射性能关键技术问题,研究了电磁发射的相关因素,并进行了仿真分析.对当前提出的几类电磁发射技术进行总结,分析了其在高功率脉冲电源,电力调节控制,轨道、弹丸材料与结构以及抗烧蚀等方面的技术问题.讨论了轨道式发射装置的教学模型,并进行仿真.对发射效率、出口速度和发射精度等指标进行数据分析.结果表明,电源功率、轨道材料性能和电力调节控制方法是影响电磁发射性能的关键因素.     

某火箭发动机系统振动特性测试和仿真分析

从计算和试验两方面分别研究了某火箭一级发动机的振动特性。侧重介绍了模态试验和商业有限元软件在发动机振动特性快速分析中的具体应用,以及发动机三维有限元模型如何应用于全箭有限元梁模型。计算结果和试验结果吻合较好。     

国外固体运载火箭技术的新进展与启示

固体运载火箭作为快速进入空间的有效手段,已成为目前各国航天运输系统的重点发展方向之一。通过对国外固体运载火箭技术的发展脉络进行分析,研究其发展历程及特点,从四方面总结出其发展趋势,即向低成本、高可靠、快速机动发射发展;向固体运载与导弹技术共用发展,深层次拓宽军民融合领域;向与捆绑式运载火箭的大型固体助推器技术共同发展,并充分利用成熟技术;向模块化、可扩展化设计发展。最后,对国内发展固体小型运载火箭提出了相关建议。