排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
Honoka Tomizaki Ryohei Kobayashi Mayumi Suzuki Nanami Karasawa Sunao Hasegawa Kanjuro Makihara 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(5):1526-1534
Deorbit methods have been employed to remove space debris from orbit. One of these methods is to utilize atmospheric drag. In this method, a membrane loaded into the spacecraft is expanded to increase atmospheric drag. Although this method works without requiring fuel, it has the disadvantage of a high risk of collision with other debris owing to its larger area. Area-time product and energy-to-mass ratio have been used as indices to evaluate the risk of collisions between spacecraft and debris. However, the evaluation criteria were uncertain because these two indices are independent. In this paper, we propose a new evaluation index, single-sheet collision factor (SSCF), that comprehensively evaluates the collision risk based on experiments simulating debris collisions. As a result of the hypervelocity collision experiment, we found that the penetration-area mass of the spacecraft affects the severity of debris collisions. In this paper, the product of the exterior-wall thickness, the exterior-wall density, and the space debris cross-sectional area defines the penetration-area mass of the spacecraft. Furthermore, we compare and evaluate various deorbit methods using SSCF. The comparison showed that the penetration-area mass of the SSCF could be quantitatively determined for the debris-collision severity due to difference in structural materials of spacecraft. SSCF will be used to create rules for space-environment conservation with the expansion of the space-development market. 相似文献
2.
Chiba I. Miura R. Tanaka T. Karasawa Y. 《Aerospace and Electronic Systems Magazine, IEEE》1997,12(9):31-41
We demonstrate the feasibility of a digital beam forming (DBF) and beam space CMA (Constant Modulus Algorithm) adaptive array antenna by implementing a digital signal processor (DSP) in ASICs using field programmable gate arrays (FPGA), this DBF can synthesize 16 multi-beams and eliminate interference signals by CMA adaptive processing. The whole function was implemented in 10 DSPs about 127,000 equivalent gates. Simple experimental results have confirmed the basic function of the DBF and BSCMA adaptive array antenna 相似文献
1