New European concept of single staged rocket to launch nano-satellites in low earth orbit (LEO)

Abstract

The possibility to launch small payloads into LEO by means of an electromagnetic railgun is the motivation of the present study. Here it is assumed that an electromagnetic railgun with barrel length of 180 m is able to launch a 120 mm diameter projectile at a speed of 6 km/s. In order to the payload achieves orbital motion and to compensate the velocity losses due to gravity and aerodynamic drag, a rocket engine which supplies the required velocity difference is integrated into the projectile structure. The development of such propelled projectile requires key technologies that could also benefit other industrial sectors. The paper presents the main concept and design aspects to be considered for such propelled projectile with special emphasis on: flight mechanics, aero/thermodynamics, materials and propulsion characteristics. The aerodynamic form of the projectile is optimized to achieve minimum drag and lower heat loads. Launch angles and trajectory optimization analysis are carried out by means of 3 degree of freedom simulations (3DOF). Furthermore, three concurrent propulsions systems are here considered for the rocket engine: solid, liquid and hybrid propellants type. The result of analysis pointed that the most promising propulsion systems are: (I) hybrid engine based on hydrogen peroxide/wax propellants and (II) liquid engine based on hydrogen peroxide/hydrocarbon propellants. The structural mass is analyzed mostly on the basis of carbon fiber reinforced materials as well as classical aerospace metallic in small amount. Finally, the paper gives a critical mark for the technical feasibility of small rockets for such missions.