1973 Concorde eclipse flight
| Company type | Prototype aircraft |
|---|---|
| Industry | Aviation, Aerospace |
| Founded | 1969 |
| Headquarters | Toulouse , France |
| Products | Supersonic jet airliner prototype |
On 30 June 1973, the supersonic jet Concorde 001 intercepted a total solar eclipse over Africa, allowing its passengers to witness totality for an unprecedented duration of 74 minutes—the longest recorded observation of such an event. Although five scientific experiments took place aboard, their overall influence was modest.
Preparation and lead-up
In May 1972, astronomer Pierre Léna from the Paris Observatory proposed observing the 1973 eclipse from an aircraft during a discussion with French Concorde test pilot André Turcat at Toulouse Airport. Léna elaborated on this project in his 2015 book Concorde 001 et l’ombre de la Lune, while Turcat provided his account in Un mythe éclipsé (2013). Previously, British astrophysicist John Beckman had attempted to use Concorde 002 for a similar observation but was refused.
By autumn 1972, Léna, Turcat, and their respective teams received authorization to commence preparations, with final clearance granted in February 1973. The mission was officially confirmed on 2 February. A test flight carrying the necessary equipment took place on 17 May during Concorde’s inaugural supersonic journey, followed by a comprehensive rehearsal lasting two hours and thirty-six minutes on 28 June.
30 June 1973
At precisely 10:08 GMT on 30 June 1973, Concorde 001 took off from Las Palmas, Gran Canaria, piloted by André Turcat and Jean Dabo. The onboard crew included Turcat, Dabo, flight mechanic Michel Rétif, radio navigator Hubert Guyonnet, Henri Perrier, along with astronomers Léna, Beckman, Donald Hall, Donald Liebenberg, Alain Soufflot, Paul Wraight, and Serge Koutchmy.
The aircraft intercepted the eclipse’s trajectory over Mauritania within one second of the scheduled time, cruising at an altitude of 58,000 feet and traveling at Mach 2. To ensure the mission's success, Mauritania restricted its airspace to commercial flights. Concorde then tracked the lunar shadow across the Sahara, passing through Mali, Nigeria, and Niger, before landing in Fort-Lamy (currently N'Djamena), Chad.
While observers on the ground experienced a maximum totality duration of 7 minutes and 4 seconds, Concorde enjoyed an extended period of totality lasting 74 minutes, with prolonged second and third contact phases lasting seven and twelve minutes respectively.
Aircraft
The Concorde prototype 001, bearing registration F-WTSS, conducted its maiden flight in 1969 from Toulouse Airport. It was powered by four twin-spool Olympus 593 engines and equipped with two inertial navigation systems. To accommodate solar observation requirements, four specially designed portholes were installed in the fuselage roof; these were fitted with infrared and optical cameras aimed at capturing detailed images of the Sun’s corona with minimal atmospheric distortion.
Today, F-WTSS is displayed at France’s Musée de l’air et de l’espace alongside Air France Concorde 213 (F-BTSD).
Scientific observations
During the flight of Concorde 001 in 1973, five scientific investigations were carried out. A team from Université Paris concentrated on studying the F-corona—dust particles located in the Sun’s outer corona. Researchers from the University of Aberdeen examined how the eclipse influenced atmospheric oxygen levels. Scientists from Los Alamos Scientific Laboratories measured fluctuations in light intensity. Meanwhile, Queen Mary College focused on detecting far-infrared emissions originating from the chromosphere.
Legacy
Although the Concorde eclipse flight attracted considerable media coverage, its scientific contributions were relatively limited. Specialists such as Kevin Reardon from the National Solar Observatory pointed out that no significant findings were published, and the overall research output was modest in comparison to the flight's widespread recognition. The principal investigator, Léna, conceded that while every experiment was successfully completed, none brought about a groundbreaking advancement in the understanding of the solar corona.
On 11 August 1999, three Concorde jets from France and the United Kingdom repeated this eclipse-chasing experience for paying passengers at a cost of $2,400 per seat. However, the duration of totality was brief—only four to five minutes—and visibility was hindered by the aircraft's small windows. A similar expedition scheduled for June 2001 was ultimately canceled following the crash of Air France Flight 4590 in 2000. Since then, eclipse chasing has been attempted aboard subsonic planes such as LATAM Airlines’ Boeing 787-9 Dreamliner and a Gulfstream V jet in 2024.
The Concorde’s record of observing a total solar eclipse for 74 minutes remains unmatched to this day.