Spacecraft
Voyager program

The identical Voyager probes, weighing 721.9 kilograms (1,592 lb), were launched in 1977 to take advantage of a rare alignment of Jupiter, Saturn, Uranus and Neptune that would allow a spacecraft to visit all four planets in one mission, and get to each destination faster by using gravity assist. In fact, the rocket that launched the probes (the Titan IIIE) could not even send the probes to the orbit of Saturn, yet Voyager 1 is travelling at roughly 17 km/s (11 mi/s) and Voyager 2 moves at about 15 km/s (9.3 mi/s) kilometres per second as of 2023. In 2012, Voyager 1 exited the heliosphere, followed by Voyager 2 in 2018. Voyager 1 actually launched 16 days after Voyager 2 but it reached Jupiter sooner because Voyager 2 was taking a longer route that allowed it to visit Uranus and Neptune, whereas Voyager 1 did not visit Uranus or Neptune, instead choosing to fly past Saturn’s satellite Titan. As of August 2023, Voyager 1 has passed 160 astronomical units, which means it is over 160 times farther from the Sun than Earth is. This makes it the farthest spacecraft from the Sun. Voyager 2 is 134 AU away from the Sun as of August 2023. NASA provides real time data of their distances and data from the probe’s cosmic ray detectors. Because of the probe’s declining power output and degradation of the RTGs over time, NASA has had to shut down certain instruments to conserve power. The probes may still have some scientific instruments on until the mid-2020s or perhaps the 2030s. After 2036, they will both be out of range of the Deep Space Network.
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