Liquid rocket engine

Advantages and disadvantages

• A liquid rocket engine can be tested prior to use, whereas for a solid rocket motor a rigorous quality management must be applied during manufacturing to ensure high reliability.
• Liquid systems enable higher specific impulse than solids and hybrid rocket motors and can provide very high tankage efficiency.
• A liquid rocket engine can also usually be reused for several flights, as in the Space Shuttle and Falcon 9 series rockets, although reuse of solid rocket motors was also effectively demonstrated during the Shuttle program.
• The flow of propellant into the combustion chamber can be throttled, which allows for control over the magnitude of the thrust throughout the flight. This enables real-time error correction during the flight along with efficiency gains.
• Shutdown and restart capabilities allow for multiple burn cycles throughout a flight.
• In the case of an emergency, liquid propelled rockets can be shutdown in a controlled manner, which provides an extra level of safety and mission abort capability.