In 1963, a NASA technician conducted a unique manual inspection of the Echo II communications satellite inside a hangar at Lakehurst, New Jersey.The satellite, a massive 135-foot-diameter Mylar balloon, was highly reflective and designed to passively relay radio signals back to Earth by reflecting them.

To ensure the balloon’s surface was free from leaks or flaws, the technician floated up and down alongside it using a small personal balloon tethered to the ground.The Echo satellite program marked a pioneering step in space communications.

Unlike modern satellites, Echo I and II carried no electronic instruments; instead, signals sent from Earth were simply bounced off their reflective surfaces to other ground stations.Echo I, launched in 1960, successfully transmitted the first transcontinental voice message, including one from President Dwight Eisenhower.

Echo II, launched in 1964, was larger and used for both scientific experiments and international signal reflections, including cooperation between the U.S.and the Soviet Union.The program provided key insights into satellite tracking, atmospheric drag, and temperature control in orbit.Additionally, technology developed for Echo contributed to discoveries in cosmic microwave background radiation, supporting the Big Bang theory.Overall, the Echo program laid the foundation for modern satellite communications and represented a significant milestone in space technology.