The proposed contract effort is for the design, development and proof-of-concept demontration testing of a low cost, pressure-fed liquid rocket booster propulsion system concept. The contract focus will be on four key component technologies in the booster system; (1)composite propellant tanks, (2)pump-fed propellant heat exchanger, (3)self-cooled engine with altitude-compensating nozzle, and (4)annular liquid-liquid engine injector. All four components will be designed and built in subscale in Phase, and will be sized for later incorporation into sub-orbital flight test vehicle. The Phase 1 contract culminates with cold flow testing of the propellant feed subsystem, which is the most novel aspect of the booster. The proposed low-cost booster design also has a low impact on natural resources, and can utilize inexpensive, renewable biofuels. The raw materials used in the contruction of the booster do not include any expensive, exotic, or stategically sensitive substances. The prospect of reusability of most of the booster mass further reduces raw material and energy consumption per launch.