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Voyager, which has achieved a new era in space exploration as a ‘human skirmisher’ for over 44 years, is about to retire. Recently, local media such as ‘Scientific American’, a US science media outlet, reported that NASA will enter a ‘shutdown’ to reduce the power of the Voyager spacecraft this year. In fact, it heralds an eternal separation, but paradoxically, this is an ordeal to prolong the life of the Voyager spacecraft.
Voyager is powered by a nuclear battery called a radioactive isotope thermoelectric generator (RTG), which is also nearing the end of its lifespan. According to NASA, Voyager loses energy by about 4 watts per year. To save even a little bit of this, NASA has operated with the heating system and various subsystems turned off in the past. However, these efforts did not resist the passage of time. The policy of reducing Voyager’s power this time is to extend its lifespan even by a few more years. Linda Spielker, a planetary scientist at NASA’s Jet Propulsion Laboratory, said, “If all goes well, the Voyager mission could be extended up to 2030.”
In this way, Voyager is scheduled to disappear to the other side of the universe, but the achievements so far have far exceeded expectations. Voyager originally started as a four-year project to explore Jupiter and Saturn, but it is because she has already continued her exploration activities 10 times more than that.
45 years of Voyager
Voyager was launched into distant space on August 20, 1977, with the grand dream of mankind. The first launcher at the time was Voyager 2. Voyager 2 was obscured by Voyager 1 due to the title ‘2’, but in fact, Voyager 1 was launched a week later. The twin probes Voyager 1 and 2 flew similar routes to Jupiter and Saturn, but afterward, Voyager 1 used a shortcut to explore the outer solar system and Uranus and Oceanic stars in sequence. Therefore, Voyager 1, which has gone the furthest among ‘human beings’, is currently flying in interstellar space, about 23.3 billion km from Earth, and Voyager 2 is also flying 19.5 billion km away.
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Voyager’s achievements so far are remarkable. Initially, Voyager’s main mission was to explore Jupiter and Saturn. Voyager 1 approached Jupiter in 1979 and sent a beautiful image of Jupiter to Earth, and the following year it was the first to confirm that Saturn’s rings had a complex structure. Voyager 2 also flew the mysterious Uranus and Neptune in close proximity, showing us their naked faces for the first and last time.
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In particular, Voyager 1 took the ‘Pale Blue Dot’, ‘the most philosophical astrophotography’ in human history, and sent it to Earth on February 14, 1990. With the idea of the famous American astronomer Carl Sagan (1934-1996) at the time, Voyager 1 turned the camera toward the Earth and captured the Earth at a distance of 6 billion km, 40 times the distance between the Earth and the Sun.
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The world we live in in that picture was just a ‘pale blue dot’. Dr. Carl Sagan said, “I wanted to teach people that the Earth is nothing more than a mere existence floating in space.” After that, Voyager continued flying out of the solar system and entered Interstellar for the first time in August 2012.
Voyager’s future
After 2030, when the remaining power is exhausted, Voyager will completely lose communication with Earth. Even so, Voyager’s voyage is non-stop, and her mission is not complete. According to NASA, about 300 years later, Voyager will reach the edge of the Oort Cloud, home of comets that surround our solar system, and it will be 16,700 years later when it arrives at Proxima Centauri, the closest star to Earth.
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Voyager also carries a golden record containing information about the Earth, including greetings, images and music in 60 languages, whose final mission is to deliver it to the aliens.
By Park Jong-ik, staff reporter pji@seoul.co.kr
