Proposal of Counter Impact Using Two-Stage Light Gas Guns

Paper number

IAC-05-B6.4.08

Author

Mr. Junichi Kitagawa, Kyushu Institute of Technology, Japan

Coauthor

Mr. Yasuhiro Akahoshi, Kyushu Institute of Technology, Japan

Coauthor

Mr. Shinya Fukushige, Kyushu Institute of Technology, Japan

Coauthor

Mr. Takao Koura, Kyushu Institute of Technology, Japan

Coauthor

Mr. Masayoshi Tadaoka, Kyushu Institute of Technology, Japan

Year

2005

Abstract

Two-Stage Light Gas Gun (TSLGG) is one of the devices to launch a projectile at hypervelocity and is used in hypervelocity impact ground tests between space debris and space structures. It can accelerate a projectile up to about 10 km/s.  In fact, relative impact velocity at Low Earth Orbit is up to 15 km/s. Then we propose a counter impact in order to raise impact velocity more than 10 km/s.  In the counter impact, delay time from propellant ignition to projectile launch is a key factor. If this time jitter is larger, impact position could be much lager. Then it is necessary to control jitter of delay time to obtain the counter impact in a limited section. We develope the new TSLGG based on the technology of Electrothermal-Chemical (ETC) gun for the 1st step. This gun can control jitter of delay time by using a condenser bank.   
 We measured delay time of ETC TSLGG and large TSLGG, the former is a projectile launcher and the latter is a target launcher in counter impact. Jitter of delay time in large TSLGG was too large compared with that in ETC TSLGG because Large TSLGG uses black powder for Ignition which has nonuniform combustion. In order to put off that effect, we plan trigger signal is sent to the condenser bank in ETC TSLGG after the projectile was launched in large TSLGG. We mounted two pressure sensors in the launch tube of large TSLGG to take passing signal of the projectile. On the other hand in ETC TSLGG, we restrained jitter of delay time by adjusting discharge patterns of the condenser bank to optimum gun operational parameters. Considering measurement results, we demonstrated possibility of the counter impact. 

Abstract document

IAC-05-B6.4.08.pdf

Manuscript document

IAC-05-B6.4.08.pdf (🔒 authorized access only).

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