Abstract: A rocket propulsion device including, a case having a propellant therein, the case in the form of a tube, a nozzle having at least part inserted in the case, and configured to discharge gas upon burning the propellant, and a locking unit disposed to be wound on the nozzle, the locking unit in the form of a band having both ends open, wherein a through hole for inserting the locking unit therein is formed at one region on a circumference of the case, and the both ends of the locking unit are located at a region facing the one region, whereby a rocket propulsion device having a simplified structure and a facilitated alignment of a thrust line can be implemented.

Abstract: A rocket propulsion device including, a case having a propellant therein, the case in the form of a tube, a nozzle having at least part inserted in the case, and configured to discharge gas upon burning the propellant, and a locking unit disposed to be wound on the nozzle, the locking unit in the form of a band having both ends open, wherein a through hole for inserting the locking unit therein is formed at one region on a circumference of the case, and the both ends of the locking unit are located at a region facing the one region, whereby a rocket propulsion device having a simplified structure and a facilitated alignment of a thrust line can be implemented.

Abstract: A side thruster module, comprises: a cavity-type body skin extending in a longitudinal direction; a first thruster arranged in the body skin and extending in a longitudinal direction; and a conversion nozzle arranged in the body skin and extending in a radial direction perpendicular to the longitudinal direction, for converting a direction of a thrust generated from the first thruster in the longitudinal direction into the radial direction. A large number of thrusters can be mounted at the side thruster module thus to generate a high thrust, and the side thruster module can be slim in the radial direction perpendicular to the longitudinal direction.

Abstract: An user authentication system for authenticating a user using an IC card in conjunction with a portable terminal used to generate a one-time password and a server used to generate a corresponding one-time password for user authentication. The IC card contains a secret key for generating a one-time password and predetermined random numbers. The portable terminal contains a card receiver for receiving the IC card, a random number memory for reading and storing, and then deleting the random numbers of the IC card, a first password generator for generating a one-time password by the secret key of the IC card and the random number, a first random number changer for changing the random number stored in the random number memory into a predetermined value and storing the changed value in the random number storing portion, and a display for displaying the processed results of the terminal and the server.