The story begins in the 1960s, when scientists first realized that an unusual alignment of the planets would allow for a unique space mission: the Grand Tour. The alignment of the outer planets Jupiter, Saturn, Uranus, and Neptune, in the late 1970s, which occurred only once every 175 years, it meant that it was possible for a spacecraft to pass over all of them without major changes to its trajectory, allowing all four planets to be explored for the price of one launch. Realizing this, NASA scientists enthusiastically began designing a mission that could make the most of this opportunity.
Initially, as part of NASA’s Mariner program, which explored the planets Mercury, Venus, and Mars, this program progressed under its own name: Voyager. The idea was to send four spacecraft, with flybys of not only the four outer planets, but also Pluto, which at that time was still technically a planet (today it is classified as a dwarf planet). However, a massive cost of one billion dollars led to the reduction of the program to two spacecraft: Voyager 1 and Voyager 2.
Both had an identical design. With a mass of approximately 825 kilos, each was equipped with a large disk to communicate with the Earth, a nuclear power system known as a radioisotope thermoelectric generator (RTG) and ten different scientific instruments to study the worlds they would visit. Those included advanced cameras to take pictures, infrared and ultraviolet tools to view their atmospheres, and magnetometers to study their magnetic fields.
The journey begins
Despite the name, Voyager 2 was the first of the two spacecraft to be launched. On August 20, 1977, he took off on a Titan-Centaur rocket, beginning his long journey into deep space. Voyager 1 followed about two weeks later, on September 5, in the same class of rocket, but this time launching on a much faster trajectory, reaching 98,169km / h, down from 90,100km / h. h of Voyager 2. 1 was designed to reach Jupiter and Saturn quickly, the first in 1979 and the second in 1980, while Voyager 2 was on a slower trajectory that would take it to Saturn in 1981. However, this slower path left open the option that if the spacecraft remained operational, it could attempt the Grand Tour and head towards Uranus and Neptune.
Voyager 1 was designed with slightly narrow objectives. Its purpose was to fly past Jupiter and Saturn, the former of which had been visited by the Pioneer 10 spacecraft, in 1973, and Pioneer 11, in 1974; the second was visited by Pioneer 11 in 1979. Excited by these missions, scientists were ready for more data, and Voyager 1 prepared in a big way. The ambitious and exciting mission would also include flying over Saturn’s tempting moon Titan, from which Today we know that it is the only place, apart from the Earth, that has liquid bodies on its surface. Many were delighted at the prospect of exploring these worlds with this advanced spacecraft. What would be discovered on his incredible journey?
Voyager 1 Discoveries
In 1978, Voyager 1 began its approach to Jupiter, taking regular images as it got closer and closer. It finally entered the so-called Jovian system in February 1979. Thus it discovered a previously known thin ring that encircled the planet, which was only about 30 kilometers thick and therefore, unlike the magnificent ring of Saturn, had been difficult to find. detect. Finally, it made its closest approach to Jupiter in March, hovering just 280,000 kilometers from the planet, before flying past many of its exciting moons, including the volcanic world of Io, icy Europa, and massive Ganymede. The spacecraft’s studies of Io were particularly interesting, revealing that this moon was the most volcanically active world in the Solar System, even more so than Earth.
By November 1979 he had reached Saturn, where he would also reap many fascinating discoveries. He found five new moons in the system and observed new properties of Saturn’s fabulous ring system. Of particular interest was Titan, which Voyager 1 discovered had a thick atmosphere made of nitrogen like Earth, which made the moon of great interest to scientists. It would not be until the joint ESA-NASA Cassini-Huygens mission, launched in the late 20th century, that we would really understand how fascinating Titan was.
After its encounter with the Saturnian system, Voyager 1’s trajectory was deliberately bent by gravitational pull, pulling it out of the system on an upward trajectory relative to the rest of the planets in the Solar System. This allowed it to start a fast path out east, into interstellar space, at a speed of about 523 million kilometers a year. While on his way, he turned, in 1990, to take a famous photo of the Earth from a distance of six billion kilometers, called the pale blue dot, which shows our planet as a tiny light in the grandeur of space, a fantastic portrait of our place in the universe. Ultimately, Voyager 1 would reach interstellar space in 2012 – and it was the first spacecraft in history to do so – when it was deemed to have left our sun’s zone of influence known as the heliosphere.
Voyager 2 Adventure
Voyager 2’s mission, meanwhile, continued. Their exploration of Jupiter, combined with data from Voyager 1, allowed scientists to map the surface of its moons Ganymede and Callisto, while also providing vital information about a huge storm that had been ravaging Jupiter for four hundred years, known like the Great Red Spot. He also discovered four moons orbiting the gas giant and provided additional data on their rings. Later, it would arrive at Saturn: it obtained new images and fascinating measurements on this and its moons. But his most impressive feat was yet to come.
Given the good health of the spacecraft, NASA decided to extend the mission and try to reach the ice giants Uranus and Neptune, the two outermost planets in our solar system. Neither of them had ever been visited by a spacecraft before, which made the Voyager 2 mission absolutely exciting. After passing Saturn, the journey to Uranus began, which would take four and a half years. It began to approach the planet in November 1985, finally reaching just 81,500 kilometers on January 24, 1986.
The event was beyond what scientists could have hoped for. Voyager 2 not only sent the first images and measurements of Uranus in the foreground, revealing fast winds in its atmosphere and an ocean of boiling water beneath its clouds, but it also found ten moons and two new rings in the system. It provided stunning images of these satellites, and sent fascinating portraits of these alien worlds that had never been seen before by the human eye.
After that, he went to Neptune, where he arrived on August 25, 1989. Once again, this planet had never been seen up close by Earthlings before. Voyager 2 not only discovered new moons and new rings, six and four, respectively, but it also discovered that the planet had winds of 1100 km / h and even some intriguing characteristics of giant storms in its atmosphere, such as the Great Dark Spot. It also returned images of Triton, a large moon that orbits Neptune and is now thought by some to be a dwarf planet captured from elsewhere in the Solar System.
Like Voyager 1, the trajectory of the spacecraft was modified to be launched into interstellar space, although this time it went down relative to the orbits of the planets, instead of going up like Voyager 1. Its speed, somewhat more Slow compared to its sister, it meant it didn’t enter interstellar space until 2018, making it the second spacecraft in history to do so after its predecessor. Both spacecraft are still operational and are more than 18 billion (Voyager 2) and 22 billion (Voyager 1) kilometers from Earth, but their diminishing power has suggested that only some of their instruments are still working. However, they are still sending information back to Earth and are expected to continue to do so until 2025.
There is little doubt that Voyager 1 and 2 they are still two of the most incredible spaceships designed and launched in history. His extraordinary journey through the outer Solar System offers us untold treasures, showing us the outer planets like never before. Their travels may be coming to an end, but they remain a shining example of engineering and a lasting legacy of humanity that will travel far across the galaxy.