The RANGER system is designed to place a 1,000 lb satellite in orbit. During engineering development, it became apparent that the thrust level of the turbines for the vehicles was fundamental in sizing the overall vehicle. The fuel efficiency of the turbines was also critical to the overall fuel capacity required to meet the various missions. In flight refueling for the turbines was added to extend the ferry range to unlimited. Pyramid Space has selected commercial and military available turbine engines for their maturity, durability and fuel efficiency.
Currently, there are no rocket engines that perform to RANGER system specifications. However, there are several engines flying or in development that may be adaptable with modification. The candidates of possible rocket engines are listed below. The NARA 1MT engine is a proposed rocket engine concept from Pyramid Space.
The Pratt & Whitney 600 series small business jet turbine is a fuel efficient compact readily available commercial engine. The engine is a larger diameter than desirable for the XS-2 but the smaller diameter, highly efficient engines used on cruise missiles may not be available due to security reasons. The Flash RANGER is designed to accommodate up to nineteen inch diameter engines which will allow several similar SBJ engines to be used.
The General Electric F404 turbine is used extensively in military aircraft around the world. The 100D is the non-after-burning version used by the Singapore A-4S-1 Super Skyhawks. The Light RANGER has flush surface inlets and cannot use turbines during supersonic flight. The 100D is significantly shorter in length which is beneficial to the vehicle configuration.
The Pratt & Whitney F100 series engines power the F15s and F16s in the US Air force and thousands of these engines have been built. They are all after-burning engines which add overall length to the engine. However, when scaling the RANGER system to the XS-15, the airframe configuration was less affected by the increase in engine diameter and length.
This engine is the innovative rocket engine concept for the flash ranger. This engine will have fully closed engine cycle, full throttle ability (0-100%), on/off capability and re-usability which are essential for space planes.
Other LOX Methane Engines
Relativity Space AEON 1
Masten Space Systems Broadsword/Cutlass
XS-2, XS-5, XS-15
The reaction control system (RCS) for the RANGER system vehicles are modular units placed in the nose and tail section similar to the US Space Shuttle design. The system propellants are still being investigated as it is highly desirable to use non-toxic propellants, which are still under development by various manufacturers.