Voyager spaceships: The 45-year-old spacecrafts that will never perish
As all of you would agree that the universe is full of incredible mysteries, many that mankind is yet to solve. At some point in life, we have all looked up and wondered at the unknown sky, the twinkling stars, the falling asteroids, and the moon shining bright.
While doing so, you must have thought about how far the sky and stars go and what exists beyond the realms of the Earth? However, perhaps the most popular question that has perhaps crossed the minds of almost everyone is: Are aliens real or are there any living beings on other planets?
To find these answers, scientists launched spacecrafts that could survive for decades in the solar system. They are called the Voyager (1 & 2). Let’s now explore what this spacecraft is doing out in space.
Voyager Programme: Exploring the solar system
For those unaware, both the Voyager spacecrafts were launched by NASA, the American space agency, to explore the solar system in depth. In fact, these spaceships were set in motion as part of the Voyager Programme. Its aim was to complete a grand tour of primarily four planets that are farther away from the Earth, namely: Jupiter, Saturn, Uranus and Neptune, considering things worked as planned! They were manufactured by Jet Propulsion Laboratories (California-based research and development centre of NASA) and launched in 1977 to explore the universe at large, much beyond our solar system.
Surprisingly, Voyager 2 was launched before the Voyager 1, although they both were put in place on days when the solar system planets were in alignment. On August 20th, Voyager 2 was the first spacecraft to be launched, followed by Voyager 1 on September 5th.
Interestingly, both the Voyagers were in close proximity while on duty. The Voyager 2 widely explored Jupiter from 1977 to 1979 and Saturn from 1979 to 1981, while the Voyager 1 could only manage to vaguely traverse Jupiter in March 1979 and Saturn in November 1980.
After travelling across Jupiter and Saturn, the two Voyagers parted ways. Thereafter, Voyager 1 explored Titan, a moon of Saturn, and Voyager 2 swung by Uranus (from 1982 to 1986) and Neptune (from 1986 to 1989).
After fulfilling their primary mission, NASA directed the Voyagers to tilt their in-built cameras towards the Earth in February 1990, when it was 6 billion kilometres away.
Since then, the Voyagers have been surveilling the Earth from far and today even after 45 years, they are still very much active, with the probes continuing their 'Interstellar' interplanetary journey. Interestingly, Voyager 1 moves at a speed of 11 miles per second, whereas the speed of Voyager 2 is 9.5 miles per second. The three plutonium-238-filled batteries on board the spacecrafts are what keep them alive even after decades.
Voyager 1 after the 90s
You must be thinking that that all gthese Voyagers did post 1990 was keeping a close eye on Earth. Well, that isn’t right. In fact, in between 1990 and 2004, the Voyager 1 travelled an additional 8 billion kilometres to reach the Terminal Shock (the boundary that marks the outer limit of the Sun’s extent in our solar system, meaning its end point).
By 2012, it had also travelled more than 18 billion kilometres and passed through the Heliopause (the imaginary boundary where interstellar medium stops solar wind). The same year, Voyager 1 also achieved a milestone by becoming the first object from Earth to enter the interstellar space (the place where the Sun's magnetic field stops affecting its surroundings).
Voyager 2 after the 90s
Wondering what the Voyager 2 was doing all this while? It was following he exact footsteps of Voyager 1 and had reached both the Terminal Shock and the Heliopause by 2018. It also moved away from the Earth, and hasn’t looked back ever since. Regardless, both the Voyager spacecrafts continue sending the Earth's message of our existence into the space.
What’s interesting is that the duo communicates with scientists by sending signals to Earth's three Deep Space Network stations using 3.7-metres (12-foot) high-gain Cassegrain antenna to transmit and receive radio waves.
The Earth might perish but the Voyagers will live on!
As already mentioned, NASA had equipped Voyager 1 and 2 with an ambitious goal: Letting extra-terrestrial life know about our existence on planet Earth. The hope is if other space travellers meet the Voyagers in the distant future, they will know about our home planet. Guess what serves as the medium of this message? A 12-inch gold-plated copper disc installed with sounds and images chosen to represent the diversity of life and culture on Earth.
But this isn’t the most fascinating thing about the spaceship duo. Okay, so what is? As long as they have the fuel and power (approximately till 2036), they will continue transmitting signals back to Earth. However, they won’t perish even when the fuel or power runs out. Instead, they will go into sleep mode. Can you imagine what this means? After a million years, the Voyager might still remain very much alive, even if the sun swallows the Earth! How crazy is that! In fact, if experts are to be believed, the Voyager spacecrafts will continue to travel in the solar system until they leave the Oort Cloud (spherical layer of frozen objects around our Sun) in another 14,000 to 28,000 years. That’s almost infinity!
What’s more intriguing is that both the solar system and the Voyager spacecrafts will have completed a full orbit around the Milky Way by 500 million years from now. However, the spacecrafts may not travel beyond the Milky Way, as they need to accelerate to a velocity of 1000 kilometres per second. Unless something unexpectedly gives them a significant velocity boost, they will likely remain in the Milky Way's spin forever!