Ethan Wong

April 14, 2023

SpaceX is now one of the most prominent space companies in the world working to improve space travel and colonize Mars. The company was founded by Elon Musk, who had two major goals for the company: to decrease the cost of space travel/payloads with reusable rockets and to send humans to the red planet. 

The first creation of SpaceX was the Falcon I, which stood around 68 feet tall and intended to reach orbit carrying its weight of 62000 pounds and a 400-pound payload. The rocket had two stages and it launched on March 24th, 2006, ending horribly with an engine failure. After two more failures, the rocket finally reached Earth’s orbit in 2008 and its final launch put a commercial satellite into space. 

Because SpaceX was a private space company, it received funding from NASA after the success of Falcon I to develop better launch vehicles to send payloads to the ISS. In 2006, SpaceX developed and launched the Falcon 9, which was a two-stage liquid-fueled rocket powered by 9 Merlin engines. The rocket had two stages, with its cluster of engines on the first stage, and a single Merlin vacuum engine on the second stage. The Merlin engines use LOX and RP-1 Kerosene and are re-ignitable, a feature that is essential for the rockets to land themselves. The Falcon 9 has launched 208 times and was the first rocket approved to carry humans to the ISS. 

The Falcon 9 Heavy rocket is another version developed by SpaceX intended to have more thrust and lift heavier payloads into space. The main difference is its addition of multiple first stages, a similar technique used on the Delta IV Heavy. The Falcon 9 Heavy uses three Falcon 9 first stages, with one acting as a core first stage (center) and the other two used as strap-on boosters. The Falcon 9 Heavy is powered using Merlin 1D engines, which contain greater thrust. 

So how does Falcon 9 land its first stage? The Falcon 9 is equipped with three crucial parts known as Grid Fins, Cold-Gas Thrusters/Boosters, and Merlin Engines. Once the first stage is separated from the second stage, the cold-gas boosters use nitrogen gas to help reorientate the rocket into a vertical position for landing. The first stage has four grid fins attached which are responsible for accuracy during the landing. However, the grid fins are not used as a drag effect to slow down the rocket, but rather a device used to control the direction of the first stage–something that the engines would have a difficult time doing. The final factor in the SpaceX rocket landing are the Merlin engines, which are ignitable after stage separation. Three out of the nine engines end up firing back up after the first stage falls into the Earth’s atmosphere and power it back down to Earth where the landing legs are then deployed to land the SpaceX vehicle. As for the Falcon 9 Heavy, the two side boosters would detach from the rocket first and land themselves. With just the core first stage and the second stage, the rocket would now act like a typical Falcon 9, following the same landing process.

The Falcon 9 and Falcon 9 Heavy rockets are still in use today, manufactured to bring satellites, payloads, and humans to space (with the Dragon capsule). 166 first stages have successfully landed, saving SpaceX billions of dollars, and allowing the private company to only focus on building second stages for future launches. While SpaceX continues to work towards Mars with its new Starship launch vehicle, the Falcon transportation system has demonstrated the capabilities of SpaceX and rocket technology.