On June 30, 1973, Concorde 001, the first prototype of the supersonic jet, flew at twice the speed of sound—Mach 2—and extended the duration of a total solar eclipse. On the ground, the eclipse would have lasted only about 7 minutes, but aboard the aircraft, the total darkness lasted 74 minutes. This was due to the plane's speed matching the movement of the Moon’s shadow, which traveled at over 2,000 km/h. The flight began in Las Palmas, in the Canary Islands, and the aircraft joined the shadow above Mauritania while flying at Mach 2.08, as noted in a text by Pierre Léna, associated with the Museum of Air and Space. At an altitude of 17,000 meters, the crew simply needed to stay within the shadow as the Earth moved beneath them. Fourteen people were on board, including six crew members and eight researchers from France, Britain, and the United States. The idea to conduct the experiment was born in May 1972 during a lunch at Toulouse airport, when Pierre Léna, an astronomer from the Paris Observatory, suggested to test pilot André Turcat that they observe the 1973 eclipse from a plane. Though approval was not immediate, by autumn 1972, Léna learned that his team and Turcat’s team could begin work, with a final decision not made until February 1973. Earlier, British astrophysicist John Beckman had been denied access to the second prototype, Concorde 002, for a similar mission. On February 2, the flight was officially announced. Concorde 001 was modified for the mission, with portholes added to the roof and observation instruments installed. A final test flight took place in Toulouse on June 27, just three days before the eclipse. Images preserved by the French National Audiovisual Institute show the prototype being prepared like a flying laboratory. The crew included André Turcat, the chief pilot, and other specialists, while the eight researchers, invited by the French National Center for Scientific Research (CNRS), conducted five experiments. They studied the solar corona at various wavelengths, with their laboratories ranging from Los Alamos to the Paris Observatory, and including locations like Kitt Peak, Queen Mary in London, and Aberdeen. According to Léna, the scientific programs were successful, and the plane landed at Fort-Lamy, now N'Djamena, in Chad. The images captured during the flight were shown on the 8 p.m. news. While Wikipedia notes that the five experiments had limited scientific impact, the performance remains impressive: 74 minutes of totality, the longest observation of a total solar eclipse ever recorded. Concorde 001 is now displayed at the Museum of Air and Space, still bearing the special livery from the eclipse mission. Commercial flights by Air France and British Airways did not begin until January 21, 1976, nearly two and a half years after this test flight.