Voyager 2: re-established contact after 7 months!
18.8 billion kilometres: do you know how many Micheal Jordan (1.98m) could fit in this huge
distance? The answer is approximately...9500000000000.
Yes, it would take 9.5*10^12 Micheal Jordan to reach Voyager 2.
Yet we are still receiving a signal from it. We are receiving information about plasma,
charged particles and solar wind. Voyager is the first interstellar missions
of humanity. We never went so far.
But, sometimes, we lose touch.
Follow me on this GRAND TOUR to get to know how we re-established contact with Voyager
2: you will find cute pictures of Neptune, Saturn, Jupiter and Uran and, maybe, Micheal
Jordan. Also, do you have any idea how do we communicate with Voyager 2? You'll find
out in this video. Enjoy!
In the summer of 1977, NASA launched two of the most iconic missions in the Era of space
exploration. We are talking about Voyager 1 and Voyager
2, that left for the tour that is known as “Gran tour of the Outer solar system”.
This trip was made possible thank to a peculiar alignment of the planet, that made possible
to make gravitational leaps from a planet to another.
This technique is known as “gravity assist”. They visited Jupiter, Saturn, and then Uran
and Neptune.
But....why did NASA launch two probes? It was because one of them had to visit Titan,
the moon of Saturn, that was at the time one of the most intriguing places in our solar
system, because it was the only moon in the solar system with a big atmosphere.
But Titan was pretty much away from Saturn, so if you wanted to visit it, you just had
to go straight in his direction. And once you've done this, you, unfortunately, can't
take back the gravitational assist from Saturn to reach Uran and Neptune.
So you can continue your trip, but you can't go in the direction of the other target planets.
So the aim was like: We launch Voyager 1 in the direction of Titan,
and if the mission works out well we can continue our grand tour by means of Voyager 2, that
isn't directed to Titan, but takes a gravitational assist to Saturn and goes toward Uran and
then Neptune! But if Voyager 1 failed, we can divert Voyager
2 and send it to Titan!
This shows that Titan was an important target to reach, in order to understand more of our
solar system, and maybe it was considered more important to reach than Saturn, Uran
and Neptune for the purpose of the mission. The only reason why we have been able to see
Uran and Neptune in that period was that Voyager 1 successfully completed his mission!
So we have to thank the effort and the passion that was put in Voyager 1 if we have been
able to visit Uran and Neptune: in fact, if Voyager 2 was diverted, maybe today we would
have missed the chance to visit two of the most important places of our Solar System!
Thanks, Voyager 1.
So everything worked out well, and Voyager 2 visited Jupiter in 1979, Saturn in 1981
and then Uran in 1986, and Neptune, the last one, in 1989.
Voyager 1 and 2 took some pictures. We suggest you to take a deep breath and see
what a beauty:
The grand tour came to an end, but the probes were still active, and so they continued to
monitor and sending pieces of information to Earth, information about the Outer solar
system: Solar wind, charged particles, stellar dust.
In fact, at that point, it wasn't much to photograph.
But why didn't Voyager visit Pluto?
It was because Pluto wasn't aligned in the right way so that they could not divert the
probe in its direction. Actually, there was an idea to send another probe, the Voyager
3, to Neptune, but unfortunately, there were no more funds, so Voyager 3 and 4 have never
been built.
But the interesting fact was that Voyager 1 and 2 continued to send data back to Earth,
and nobody was expecting to see them surviving much longer.
Somebody was saying that maybe they could've resisted until 1995, or something like that,
maybe even until the year 2000...but the only one that was imagining a longer life was Carl
Sagan, that was the chief for Voyager images reconnaissance, but he is most known as the
one who created a message that wasn't designed for humans: the “Golden Record”.
That message is a collection of images, sounds, and mathematical symbols recorded on a gold-plated
phonograph disc that's still flying through space today, 17/12/2020.
Since NASA knew the spacecraft would travel farther than any manmade object in history,
the space agency decided each robot should carry a message in case an intelligent civilization
bumped into one of them. Sagan led the committee tasked with putting that message together.
However, the Voyager missions went further than Carl Sagan ever dreamed: guess what?
They are still active! And not only do they still say HELLO to us,
but they are actually making true science, true scientific discoveries about an ambient
that we never visited before them. These are the first interstellar missions
of humanity. This is the first time that we do such an
experiment, so every time we receive some new info about charged particles, plasma,
electric fields, from Voyager, we can test our models and verify whether they are correct
or not.
Anyway, after the probe was left flying solo for 7 months while repairs were made to the
radio antenna in Australia used to control it, on October 29, NASA re-established contact
with its Voyager 2 spacecraft. Mission operators sent a series of test commands
to Voyager 2 using the antenna, which established a signal confirming the “call” was received.
The spacecraft executed the commands without issue, according to a NASA statement.
Can you imagine how amazing is it? Voyager 2 has been travelling through space
since its launch in 1977 and is now more than 11.6 billion (BILLION!!!!) miles (18.8 billion
km) from Earth. It's about the same distance that you would
travel if you went around the world for 469.120 times, or maybe one can imagine that it is
the distance travelled by the speed of light in a light interval of 21h 01m 44s.
But this is not the end, because... Voyager 1 is now more than 22.695 billion
km from Earth. If this distance was covered by Micheal Jordan's
height (1.98 m), we would have that the Earth-Moon distance would be 0.033 mm.
We are veeeeeery small.
But...they are too far from us: how do we communicate with Voyager?
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Well, we send radio waves. Electromagnetic waves travel at the speed
of light so, as we said before, it takes 21 h 01m 44s for a signal to go fro Earth to
Voyager. Double this time and you'll get the time we
need to have a conversation with Voyager 2. In order to communicate with Voyager, we make
us of a series of antennae around the world (Deep Space Network).
The antennae diameter is about 70m, that is about...(guess what?) 36 Michael Jordans.
One of these antennae is the so-called “DSS 43 antenna”.
Deep Space Station 43 (DSS-43) was constructed in 1969 to 1973 as a 64-metre diameter antenna.
The 64-metre antenna was more than six times as sensitive as DSS-42, the original 26-metre
at the Complex. Therefore DSS-43 could communicate with spacecraft at greater distances from
Earth as the signal became weaker. DSS-43 supported, as needed, the Apollo 17 mission
to the Moon before the antenna's official opening in 1973.
DSS-43 was extended from a 64-metre diameter antenna to a 70-metre diameter in 1987 to
enhance its capabilities for the Voyager 2 1989 encounter with Neptune. It is the largest
steerable parabolic antenna in the Southern Hemisphere. Recently we updated it again.
And that's how we re-established contact with Voyager 2.
"What makes this task unique is that we're doing work at all levels of the antenna, from
the pedestal at ground level all the way up to the feedcones at the centre of the dish
that extends above the rim," says NASA Deep Space Network project manager Brad Arnold.
"This test communication with Voyager 2 definitely tells us that things are on track with the
work we're doing."
We hope that we can continue to communicate with Voyager at least until 2027.
It will depend mostly on the amount of energy (plutonium).
Plutonium will continue to a decade until it won't be able to provide sufficient energy
to the various instruments on board Voyager 2.
Anyway, if it could reach the year 2027, it would be amazing, because it would be the
50th anniversary of the launch. Meanwhile, Voyager missions are continuing
to provide science for us.
Before ending this video, we would like to show you how the Earth looked like when Carl
Sagan decided to take a picture from Voyager 1, when it was six billion kilometres away,
far beyond the orbit of Neptune.
The Earth (the blue dot about halfway across the brown band on the right) seen from 6 billion
kilometres appears as a small dot in the darkness of deep space.
Voyager also took similar photographs of Venus, Jupiter, Saturn, Uranus and Neptune. Assembled
together they form the photo called Family Portrait. The planet Mercury was not photographed
due to its proximity to the Sun and Mars is not visible due to the effects of sunlight
on the camera optics.
In 2001, in an article on Space.com, Ray Villard of the Space Telescope Science Institute and
Jurrie Van der Woude of the Jet Propulsion Laboratory voted the photo as one of the ten
best scientific images of space of all time.
We are living in a fantastic era. An era in which we can send a probe to the
Outer Solar system and still communicate with it.
An era in which we have a powerful instrument to use for our purpose.
An era in which we can see the Earth getting smaller and smaller, becoming pale blue dot,
and then fading away from our line of sight. The Voyager Era.
"This video ends here! Thanks for watching everyone! Are you happy that we re-established
contact with Voyager 2? Do you think we could keep in touch with it until 2027? Did you
enjoy this video? Let us know in the comment below!
See you next time on the channel!