טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentFridman Gidon
SubjectStudy of a Cycle Combining Rocket/Ram-Rocket for Space
Launcher
DepartmentDepartment of Aerospace Engineering
Supervisor Professor Emeritus Alon Gany


Abstract

In the last decades, extensive theoretical research has been done in the field of new propulsion systems for space launcher, that use air as the oxidizer at some part of the trajectory.

The engines combine both rocket and air-breathing propulsion (such as turbojet, ramjet and scramjet). By using air-breathing engines, the takeoff weight can be reduced and the payload capability (the percentage of payload from takeoff weight) can be increased. Most of the research is conducted on engines using hydrogen fuel to increase energetic performance. There have also been studies of propulsion systems using hydrocarbon fuels (solid and liquid). These engines have lower energetic performance relative to those using hydrogen, but are still superior compared to solid/liquid rocket engines. The combined cycles are designed mostly for space plane configurations. 

 The present work studied the possibility of a new space launcher that uses a ducted rocket (which is an air-breathing engine) at the first stage. The subjects of the work were: influence of take-over Mach number of the ducted rocket, gas-generator momentum influence, dispersion sensitivity, maximum satellite weight, air launch, and hybrid ducted rocket engine possibility.

The results show an improvement in the payload capability of such a launcher relative to a similar one using solid /liquid rocket engine for the first stage. It means, that for the same launch mass, the satellite mass will be higher in the new proposed configuration.

In addition to its better performance, such a launcher has the advantages of using existing technologies and keeping mechanical simplicity.