Hypersonic speed refers to speeds that are five times or more the speed of sound, which is approximately 3,836 miles per hour (6,174 kilometers per hour) at sea level. This means that anything traveling at hypersonic speeds can cover vast distances in a very short amount of time, making it a significant area of interest for both military and civilian applications. Vehicles designed to achieve hypersonic speeds, such as certain types of missiles and spacecraft, face unique challenges, including extreme heat and pressure. Research in this field aims to improve technology for faster travel and more efficient transportation, potentially revolutionizing how we move around the globe.