#NASA #Voyager1 Launched Mon, 05 Sept 1977. The concept of the #GrandTour began in 1964, when #GaryFlandro of the #JetPropulsionLaboratory (#JPL) noted that an alignment of Jupiter, Saturn, Uranus, and Neptune that would occur in the late 1970s would enable a single spacecraft to visit all of the outer planets by using #GravityAssists. The particular alignment occurs once every 175 years. The two spacecraft that launched retained the same mission concept. Voyager 1's course was optimized for Saturn’s moon Titan flyby and Voyager 2 for the Grand Tour. Voyager 2 would reach Saturn nine months after Voyager 1, giving plenty of time to decide if it should proceed with the Grand Tour. And carrying #GoldDisc records. Distance from Earth 23,546,768,809 km Distance from Sun 157 AU Velocity (from the Sun) 16.9995 kps (61198.2 kph) One-Way Light Time 21:19:13 (hh:mm:ss) On Aug. 25, 2012, #Voyager 1 flew beyond the heliopause and entered #InterstellarSpace, making it the first human-made object to explore this new territory. At the time, it was at a distance of about 122 AU, or about 18 billion kilometres from the sun. This kind of interstellar exploration is the ultimate goal of the #VoyagerInterstellarMission. Voyager 2, which is traveling in a different direction from Voyager 1, crossed the heliopause into interstellar space on November 5, 2018. The Voyager spacecraft are still communicating through the #DeepSpaceNetwork and obtaining useful interplanetary, and possibly interstellar, fields, particles, and waves science data until around the year 2025 when the spacecraft's ability to generate adequate electrical power for continued science instrument operation will come to an end. https://www.instagram.com/p/CiHU3szJFu5/?igshid=NGJjMDIxMWI=