A journey towards the intestellar space (VOYAGER 1&2)

Image: PICRYL 

In 1966, Gary Arnold Flandro, an American aerospace engineer, discovered that, 11 years later, in 1977, all the planets in the solar system converged in a straight line. This event happens only once every 175 years. 

At this time, all the planets can be explored in less time if a spacecraft is launched into space. Realizing that this would also require less fuel, he petitioned NASA to send a spacecraft at that time. But it took six years for the funds to be allocated. Then, in 1972, two spacecraft began to be built. 

Five years later, in 1977, two spacecraft, Voyager-1 and Voyager-2, were built. Both of them were similar in structure and size. Even their weight was equal.

These two spacecraft are equipped with 11 instruments like spectrometers, magnetometers, plasma detectors, etc. Its magnetometer extends a short distance forward of the spacecraft. Its job is to measure the magnetic fields of other planets. The magnetometer is fixed before the spacecraft, as shown in the picture, so that it is not affected by the magnetic field from some of the electronic meters on the spacecraft.

Image: wikimedia commons 

Another important item in this is the golden disc. Perhaps this system is installed on the spacecraft to let them know our location in case any aliens catch it. On this plate, our scientists added some information without using any numbers or letters in any language. They used just pictures and some symbols! Information such as the location of our earth in space, the image of the hydrogen atom, the method of listening to the sound stored on the plate, etc. were added to this gold-coated plate.

Image: wikimedia commons 

Perhaps if aliens knew how to listen to the sound from this record, they would hear songs that could run for nearly 95 minutes. Most of them will be music from West Asian countries. They are greeted in 55 languages on earth. They will also hear the sounds of animals, wind, water, and birds on earth. 

Both of these spacecraft were launched into space for different purposes. Voyager-1's primary mission is to leave the solar system after only exploring two planets, Jupiter and Saturn. 

Voyager-2's primary mission is to leave the Solar System after exploring planets like Jupiter, Saturn, Uranus, Neptune, Pluto, and their moons. 

On August 20, 1977, the Voyager 2 spacecraft was first launched into space. Voyager 1 was launched on September 1.

However, Voyager 1, the second mission, was the first to reach Jupiter. Also, the spacecraft confirmed that Jupiter also has a small ring system! Later, it studied some of its moons: Ganymede, Callisto, Io, and Europa. The spacecraft then continued its journey towards Saturn. 

As it approached Saturn, it first sent a faint close-up photo of Saturn. 

Image: PICRYL 

Later, it studied some of the moons of this planet and took some photographs. 

After completing all these studies, the spacecraft started its journey towards interstellar space. In this region, there is no influence from the sun's gravity. 

On this side, after Voyager-2 probed the planets like Jupiter, Saturn, Uranus, Neptune, Pluto, and their moons and sent their pictures, it too started its journey towards deep space. The spacecraft underwent some repairs when it reached Saturn. But our scientists have fixed that too, from Earth.

In both of these spacecraft, solar boards are not used. Readers can understand the reason for this. The reason for this is that the luminosity of sunlight decreases as it moves out of the solar system, so these spacecraft cannot generate energy. 

Instead, a battery-like system called a radioisotope thermoelectric generator (RTG) is used. A radioactive meter called Uranium 238 is used inside this device. Since this material is kept in a closed container, the radiation that is emitted from it collides inside the container and keeps moving. The function of this device, called RTG, is to convert this kinetic energy into electrical energy. In this way, both of these spacecraft are powered. As the radioactivity of this radioactive substance, Uranium 238 decreases, the amount of electrical energy that can be generated from it also decreases. 

The Voyager 1 spacecraft crossed the Solar System and entered deep space on August 25, 2012. Then, six years later, in 2018, the Voyager 2 spacecraft also entered deep space. 

 Path of voyager 1 and 2

Now, both of these spacecraft have been launched for more than 47 years! But our scientists predicted that these two spacecraft would only work for 8 to 15 years. Even now, these two spacecraft are in contact with the Earth. 

Currently, Voyager 2's antenna is moved 2° away from Earth, so we are currently unable to receive information from it! But, since this has happened so many times, scientists believe that this problem can be easily fixed.

As these two spacecraft have completed their assigned tasks and their batteries are running low, our scientists have switched off some of their instruments. Now only four instruments are operational on these two spacecraft. Their cameras are also temporarily disabled!

Where is voyager now? 

Voyager 1 is now 24,500 million kilometers from Earth. And it is moving at a speed of 17 km/s. The Voyager 2 spacecraft is 20,000 million kilometers away. Also, it is moving at a speed of 15 km/s. 

If Voyager 1 continues on its current trajectory, it is estimated that it will approach the constellation Ophiuchus in 38,200 years. Similarly, Voyager 2, if it continues its journey, will approach the star Ross 248 in another 40,000 years. At that time, the spacecraft would be 1.7 light years away from that star!

But it is said that their batteries will work only until 2036. After that, the two spacecraft will drift through space like normal objects. But let's not forget that the golden disc in these two spaceships is carrying information about us. 

If aliens find these spacecraft in the future, they may also come to find our Earth!

It's amazing how an old technology from 40 years ago is still in touch with scientists today!

The Voyager 1 spacecraft took one last family photo of our solar system before leaving the solar system. 

Image: wikimedia commoms 

Carl Segan, an American astronomer who played an important role in the development of the Golden Disc, wrote about the pale blue dot in this photo. His statement is as follows: 

The pale blue dot 
Image: flickr

"We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam. The earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity -- in all this vastness -- there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It's been said that astronomy is a humbling, and I might add, a character building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known."

-carl reluctant