直升机机动性设计准则

首先给出了直升机机动性的定性解释，然后分析了桨盘载荷，桨叶载荷，装机功率、等六个设计参数对直升机的悬停跃升，平飞加速等六种机动飞行的影响，进而得出了这种机动性的设计准则，为武装直升机初步设计中的机动性设计提供了依据。     

基于可靠性优化的芯片自愈型硬件细胞阵列布局方法

以提高可靠性为目标,研究芯片自愈型硬件细胞阵列布局的新结构和新方法。针对传统可靠性模型无法体现细胞内部模块随布局结构动态变化的不足,通过细胞单元电路资源消耗分析,面向二维阵列结构进行了新的可靠性建模。根据新模型,在分析布局结构参数对可靠性影响程度的基础上,提出了一种先分块再分层的细胞布局新结构。用实例验证了新布局结构对可靠性提高的有效性,给出了不同设计任务和细胞电路设计方法情况下确定最佳布局方式的计算方法,并总结出了新布局结构中分块、分层参数选择规律,最终论证了最佳布局方式计算方法和参数选择规律的一般适用性。     

Low-Cost Operation of the ORBCOMM Satellite Constellation

Financial pressures are forcing organizations to minimize operations costs. Although the easiest way to achieve this goal is simply to reduce operational requirements, often this is not possible. Therefore, automation must be employed. This paper discusses the system trade-offs that must be performed to maximize the impact of automation efforts. The discussion begins with the development of generic automation guidelines. Since many automation issues are program-specific, the paper addresses the application of these principles to operation of the ORBCOMM satellite constellation. This example demonstrates how automation can be used to produce a highly efficient satellite operations system.     

International Practices to Protect the Geostationary Ring

Since more than 20 years reorbiting of geostationary satellites at the end of their mission is recommended and partially performed to protect the GEO environment. Now a worldwide accepted reorbiting altitude was defined by the Inter-Agency Space Debris Coordination Committee (IADC). Still only one-third of the aging satellites follow this IADC rule. Based on orbital data in the DISCOS database, the situation in the geostationary ring is analyzed. From 878 known objects, 305 are controlled inside their longitude slots, 353 are drifting above, below or through GEO, and 125 are in a libration orbit (status of January 2001). In the last four years (1997–2000) 58 spacecraft reached end-of-life. Twenty of them were reorbited in compliance with the IADC recommendations, 16 were reorbited below this recommendation and 22 were abandoned without any end-of-life disposal manoeuvre.     

Space debris mitigation in geosynchronous orbit

In order to preserve the geosynchronous region, the Inter-Agency Space Debris Coordination Committee (IADC) proposed and endorsed a re-orbiting strategy for spacecraft at the end-of-life: they should be disposed above the synchronous altitude and passivated, to reduce the risk of inadvertent explosions. The recommended perigee altitude of the disposal orbit took into account all relevant perturbations and was a function of the expected perturbing acceleration induced by solar radiation pressure. It was intended to prevent any further interference with a properly defined geostationary protected region.     

Disposal orbits for GEO spacecraft: A method for evaluating the orbit height distributions resulting from implementing IADC guidelines

Geostationary orbit (GEO) is the most commercially valuable Earth orbit. The Inter-Agency Space Debris Coordination Committee (IADC) has produced guidelines to help protect this region from space debris. The guidelines propose moving a satellite at the end of its operational life to a disposal orbit, which is designed so that satellites left there will not infringe the operational GEO region within a period of at least 100 yr.