Mariner 10 completes its first flyby of Mercury and makes the first use of a flyby, suggested by Italian Giuseppe “Bepi” Colombo. The Paduan professor, in fact, is invited by JPL in the United States to participate in a conference on Mariner 10’s Mercury-bound mission. When he looks at the probe’s calculated orbit, he notes that Mariner 10 would have an orbital period around the Sun equal to 2 times a Mercury year. Therefore, he suggests carefully calibrating the first pass over Mercury so that the spacecraft has exactly the right velocity difference (Delta-V) from the planet to re-encounter Mercury on the next orbit. His suggestion was fully accepted, and thanks to him, Mariner 10 (launched in 1973 on its way to Venus) made its first flyby of Venus in February 1974, then of Mercury in March, and a second flyby of Mercury in September 1974, and a third in September 1975. The change in trajectory identified by Giuseppe Colombo, known as Bepi, significantly increased the scientific return of the mission, as well as scientific knowledge of the planet Mercury. The flyby maneuver would be used extensively in countless other interplanetary missions.
