首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7篇
  免费   0篇
航空   2篇
航天技术   2篇
航天   3篇
  2021年   1篇
  2004年   1篇
  1990年   1篇
  1988年   1篇
  1985年   1篇
  1981年   1篇
  1975年   1篇
排序方式: 共有7条查询结果,搜索用时 62 毫秒
1
1.
The different advances in the Micro Ecological Life Support System Alternative project (MELISSA), fostered and coordinated by the European Space Agency, as well as in other associated technologies, are integrated and demonstrated in the MELISSA Pilot Plant laboratory. During the first period of operation, the definition of the different compartments at an individual basis has been achieved, and the complete facility is being re-designed to face a new period of integration of all these compartments. The final objective is to demonstrate the potentiality of biological systems such as MELISSA as life support systems. The facility will also serve as a test bed to study the robustness and stability of the continuous operation of a complex biological system. This includes testing of the associated instrumentation and control for a safe operation, characterization of the chemical and microbial safety of the system, as well as tracking the genetic stability of the microbial strains used. The new period is envisaged as a contribution to the further development of more complete biological life support systems for long-term manned missions, that should be better defined from the knowledge to be gained from this integration phase. This contribution summarizes the current status of the Pilot Plant and the planned steps for the new period.  相似文献   
2.
This article examines the current legal status of commercial activities in space and describes the legislation — both national and international — existing for their regulation. The question of who is responsible for the action of non-governmental entities is thoroughly discussed, as is the notion of freedom of enterprise. Finally the author looks at the most commercialized areas of space activities — telecommunications and Earth observations — before drawing some conclusions on likely future trends in the privitization and regulation of space activities.  相似文献   
3.
4.
By means of a statistical analysis of the rotational properties of asteroids, we define a class of large amplitude and short period objects (LASPA). A possible interpretation of their collisional evolution and present physical status, in terms of ellipsoidal figures of equilibrium, is proposed.  相似文献   
5.
Simultaneously received transmission from NNSS satellites by two or more Doppler receivers can be processed as interferometric observables. The receivers are physically unconnected and the coherence of the phase information recordings (Doppler counts) is ensured by highly stable independent local oscillators similarly as in VLBI. The purpose of the interferometric processing is to obtain high precision geodetic distance determinations using NNSS Doppler data.  相似文献   
6.
7.
Michel Bour  ly 《Space Policy》1990,6(4):323-331
Transatlantic cooperation has played a key part in developing Europe's capabilities in space, but this has been despite serious drawbacks in the legal status of the agreements concerned. This article traces the history of transatlantic space relations and highlights the misunderstandings that have arisen. These stem from the precedence given in the USA to domestic laws and financial interests over all international agreements except formal treaties, which are generally not considered suitable for scientific and technical agreements. The article concludes with a discussion of how more stable and equitable relationships could be achieved.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号