section_path: Economy/Science, technology, spaceflight and energy
section_name: Science, technology, spaceflight and energy
paragraph_text: Science, technology, spaceflight and energy
  
  The United States has been a leader in technological innovation since the late 19th century and scientific research since the mid-20th century. Methods for producing interchangeable parts and the establishment of a machine tool industry enabled the large-scale manufacturing of U.S. consumer products in the late 19th century. By the early 20th century, factory electrification, the introduction of the assembly line, and other labor-saving techniques created the system of mass production. The United States is widely considered to be the leading country in the development of artificial intelligence technology. In 2022, the United States was the country with the second-highest number of published scientific papers. As of 2021, the U.S. ranked second by the number of patent applications, and third by trademark and industrial design applications. In 2023, the United States ranked third in the Global Innovation Index. The U.S. has the highest total research and development expenditure of any country and ranks ninth as a percentage of GDP. In 2023, the United States was ranked as the second most technologically advanced country in the world by Global Finance.
  
  The United States has maintained a space program since the late 1950s, beginning with the establishment of the National Aeronautics and Space Administration (NASA) in 1958. NASA's Apollo program (1961 – 1972) achieved the first crewed Moon landing with the 1969 Apollo 11 mission; it remains one of the program's most significant milestones. Other major endeavors by NASA include the Space Shuttle program (1981–2011), the Voyager program (1972 – present), the Hubble and James Webb space telescopes (launched in 1990 and 2021, respectively), and the multi-mission Mars Exploration Program (Spirit and Opportunity, Curiosity, and Perseverance). NASA is one of five agencies collaborating on the International Space Station (ISS); U.S. contributions to the ISS include several modules, including Destiny (2001), Harmony (2007), and Tranquility (2010), as well as ongoing logistical and operational support. The United States private sector dominates the global commercial spaceflight industry. Prominent American spaceflight contractors include Blue Origin, Boeing, Sierra Space, and SpaceX. NASA programs such as the Commerical Crew Program, Commercial Resupply Services, Commercial Lunar Payload Services, and NextSTEP have facilitated growing private-sector involvement in American spaceflight.
  
  As of 2023, the United States receives approximately 84% of its energy from fossil fuel and the largest source of the country's energy came from petroleum (38%), followed by natural gas (36%), renewable sources (9%), coal (9%), and nuclear power (9%). The United States constitutes less than 4% of the world's population, but consumes around 16% of the world's energy. The U.S. ranks as the second-highest emitter of greenhouse gases.