The F-1 engine is a powerful rocket engine developed by Rocketdyne for the Saturn V launch vehicle used in the Apollo program. It burns a combination of liquid oxygen and RP-1, a refined form of kerosene, to produce a thrust of about 1.5 million pounds. This made it the most powerful single-chamber liquid-fueled rocket engine ever built. The F-1 engine played a crucial role in sending astronauts to the Moon during the Apollo 11 mission. Five F-1 engines were used in the first stage of the Saturn V, known as the S-IC stage, which propelled the rocket through the initial phase of its ascent.