排序方式: 共有14条查询结果,搜索用时 15 毫秒
1.
卫星多载荷转动部件工作态下,磁性呈多极化形态,产生动态磁场。多个动态磁场叠加后,会导致卫星整器各向磁矩发生周期性变化,即磁矩波动。磁矩波动的振幅取决于各器载转动部件的数量、转动频率、固有磁矩大小以及载荷工作电流。文章以某遥感卫星动态磁场数据为模型,通过测试分析卫星整星及主要转动部件的磁场和磁矩,掌握了卫星及转动部件单机动态磁场的变化规律和特征,揭示了动态磁场导致磁矩波动的原因。研究成果可为类似多转动部件遥感卫星的磁性设计和控制提供参考。 相似文献
2.
3.
4.
The US civilian space program is focused on planning for a new round of human missions beyond Earth orbit, to realize a ‘vision’ for exploration articulated by President George W. Bush. It is important to examine this ‘vision’ in the broader context of the global enterprise of 21st century space exploration. How will extending a human presence into the Solar System affect terrestrial society and culture? What legal, ethical and other value systems should govern human activities in space? This paper will describe the current environment for space policy making and possible frameworks for future space law, ethics and culture. It also proposes establishment of a World Space Conference to aid deliberations on the above. 相似文献
5.
瑞士威力铭-马科黛尔公司 《航空制造技术》2008,(13)
瑞士加工中心制造商威力铭-马科黛尔公司着重于质量和生产效率,主要活跃于航空/航天、精密机械、钟表和医疗行业,并以其为用户提供的高性能交钥匙解决方案而著称. 相似文献
6.
7.
8.
Linda Billings 《Space Policy》1997,13(3):187-190
The concept of space as a frontier to be conquered remains extremely powerful, especially for the USA. This viewpoint argues that it is outmoded and in urgent need of replacement. In particular, the pursuit of profit, responsible for colonization and damaging exploitation in the past, and which has resulted in the trend for highly expensive space infrastructure projects, some of which may never fly, must be tempered. Space exploration should concentrate rather on promoting learning and intellectual growth. 相似文献
9.
Billings L Cameron V Claire M Dick GJ Domagal-Goldman SD Javaux EJ Johnson OJ Laws C Race MS Rask J Rummel JD Schelble RT Vance S 《Astrobiology》2006,6(5):735-813
The Astrobiology Primer has been created as a reference tool for those who are interested in the interdisciplinary field of astrobiology. The field incorporates many diverse research endeavors, but it is our hope that this slim volume will present the reader with all he or she needs to know to become involved and to understand, at least at a fundamental level, the state of the art. Each section includes a brief overview of a topic and a short list of readable and important literature for those interested in deeper knowledge. Because of the great diversity of material, each section was written by a different author with a different expertise. Contributors, authors, and editors are listed at the beginning, along with a list of those chapters and sections for which they were responsible. We are deeply indebted to the NASA Astrobiology Institute (NAI), in particular to Estelle Dodson, David Morrison, Ed Goolish, Krisstina Wilmoth, and Rose Grymes for their continued enthusiasm and support. The Primer came about in large part because of NAI support for graduate student research, collaboration, and inclusion as well as direct funding. We have entitled the Primer version 1 in hope that it will be only the first in a series, whose future volumes will be produced every 3-5 years. This way we can insure that the Primer keeps up with the current state of research. We hope that it will be a great resource for anyone trying to stay abreast of an ever-changing field. 相似文献
10.