Space Exploration Technologies Corp. (doing business as SpaceX) is an American spacecraft manufacturer, space launch provider, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk, with the goal of reducing space transportation costs to enable the colonization of Mars. It manufactures the Falcon 9 and Falcon Heavy launch vehicles, several rocket engines, Cargo Dragon, crew spacecraft, and Starlink communications satellites. SpaceX has gained worldwide attention for a series of historic milestones. It is the only private company ever to return a spacecraft from low-Earth orbit, which it first accomplished in December 2010. The company made history again in May 2012 when its Dragon spacecraft attached to the International Space Station, exchanged cargo payloads, and returned safely to Earth — a technically challenging feat previously accomplished only by governments. Since then Dragon has delivered cargo to and from the space station multiple times, providing regular cargo resupply missions for NASA. SpaceX has developed three launch vehicles. The small-lift Falcon 1 was the first launch vehicle developed and was retired in 2009. The medium-lift Falcon 9 and the heavy-lift Falcon Heavy are both operational. The Falcon 1 was a small rocket capable of placing several hundred kilograms into low Earth orbit. It launched five times between 2006 and 2009, of which 2 were successful. The Falcon 1 was the first privately funded, liquid-fueled rocket to reach orbit.

Falcon 9 is a medium-lift launch vehicle capable of delivering up to 22,800 kilograms (50,265 lb) to orbit, competing with the Delta IV and the Atlas V rockets, as well as other launch providers around the world. It has nine Merlin engines in its first stage. The Falcon 9 v1.0 rocket successfully reached orbit on its first attempt on 4 June 2010. Its third flight, COTS Demo Flight 2, launched on 22 May 2012, and launched the first commercial spacecraft to reach and dock with the International Space Station (ISS). The vehicle was upgraded to Falcon 9 v1.1 in 2013, Falcon 9 Full Thrust in 2015, and finally to Falcon 9 Block 5 in 2018. The first stage of Falcon 9 is designed land, be recovered, and reflow.

The Falcon Heavy is a heavy-lift launch vehicle capable of delivering up to 63,800 kg (140,700 lb) to Low Earth orbit (LEO) or 26,700 kg (58,900 lb) to geosynchronous transfer orbit (GTO). It uses three slightly modified Falcon 9 first stage cores with a total of 27 Merlin 1D engines. The Falcon Heavy successfully flew its inaugural mission on 6 February 2018, launching Musk's personal Tesla Roadster into heliocentric orbit

Both the Falcon 9 and Falcon Heavy are certified to conduct launches for the National Security Space Launch (NSSL). As of 31 August 2022, the Falcon 9 and Falcon Heavy have been launched 176 times, resulting in 174 full mission successes, one partial success, and one in-flight failure. In addition, a Falcon 9 experienced a pre-flight failure prior to a static fire test in 2016. SpaceX's low launch prices, especially for communications satellites flying to geostationary transfer orbit (GTO), have resulted in market pressure on its competitors to lower their own prices. Prior to 2013, the openly competed Comsat launch market had been dominated by Arianespace (flying the Ariane 5) and International Launch Services (flying the Proton). With a published price of US$56.5 million per launch to low Earth orbit, Falcon 9 rockets were the cheapest in the industry. European satellite operators are pushing the ESA to reduce launch prices of the Ariane 5 and the future Ariane 6 rockets as a result of competition from SpaceX.

SpaceX ended the United Launch Alliance (USA) monopoly of U.S. military payloads when it began to compete for national security launches. In 2015, anticipating a slump in domestic, military, and spy launches, USA stated that it would go out of business unless it won commercial satellite launch orders. To that end, USA announced a major restructuring of processes and workforce in order to decrease launch costs by half.

Congressional testimony by SpaceX in 2017 suggested that the NASA Space Act Agreement process of "setting only a high-level requirement for cargo transport to the space station [while] leaving the details to industry" had allowed SpaceX to design and develop the Falcon 9 rocket on its own at a substantially lower cost. According to NASA's own independently verified numbers, SpaceX's total development cost for the Falcon 9 rocket, including the Falcon 1 rocket, was estimated at US$390 million. In 2011 NASA estimated that it would have cost the agency about US$4 billion to develop a rocket like the Falcon 9 booster based upon NASA's traditional contracting processes, about ten times more. In May 2020, NASA administrator Jim Bridenstine remarked that thanks to NASA's investments into SpaceX, the United States has 70% of the commercial launch market, a major improvement since 2012 when there were no commercial launches from the country.