Title: Voyager 1 glitch? Strange Signals from the probe challenge engineers at NASA
The twin Voyager 1 and 2 are perhaps two of the most famous spacecrafts in the history
of space exploration. They are pure gold, pure record holders. For instance, just think
about the fact that they were designed to explore Jupiter and Saturn, but the mission
was extended and flew to Uranus and Neptune, and then further and further, reaching the
outermost edge of the Sun's domain. And beyond.
are exploring where nothing from Earth has flown before. Continuing on their more-than-40-year
journey since their 1977 launches, they each are much farther away from Earth and the sun
than Pluto. In August 2012, Voyager 1 made the historic entry into interstellar space,
the region between stars, filled with material ejected by the death of nearby stars millions
of years ago. Voyager 2 entered interstellar space on November 5, 2018, and scientists
hope to learn more about this region. Both spacecraft are still sending scientific information
about their surroundings through the Deep Space Network, or DSN.
As we said, the primary mission was the exploration of Jupiter and Saturn.
These are some pictures they took:
This first one shows in great detail part of the atmosphere of Jupiter. It is so colourful,
it seems to come directly from a Van Gogh painting!
This one instead, shows Saturn and its rings.
While Voyager 2 was behind Saturn, its radio beam penetrated the upper atmosphere and measured
temperature and density. Minimum temperatures of 82 Kelvins were found at the 70-millibar
level. Notice that the surface pressure on Earth is 1,000 millibars!
The temperature increased to 143 Kelvins at the deepest levels probed - about 1,200 millibars.
Near the north pole, temperatures were instead about 10 degrees Celsius.
As you can see, Voyager's data provided us with really important pieces of information
about Jupiter, Saturn and their moons. It is also the only spacecraft to have visited
Uranus and Neptune. But now, Voyager 1 seems to have some problems
with telemetry data. What does it mean?
Follow me in this video to get to know more about it!
========================================== Imagine that you could not talk to your friends
or family for six months. No Instagram, no facetime, no phone calls, not even a letter.
Now, imagine that you are also floating 250 miles above Earth. What are some challenges
you might face getting or receiving a message?
This is exactly what engineers have to think about before planning an interplanetary mission,
and it is not a simple thing. It is at least as difficult as it seems.
Communications with satellites and probes are extremely important because it's only
through the that we are able to receive data from space. If something starts going bad,
our data will be compromised.
The in situ collection of measurements or other data at remote points and their automatic transmission to
receiving equipment for monitoring is called Telemetry.
The word is derived from the Greek roots tele, "remote", and metron, "measure".
Telemetry must work well for a probe. If not, everything is messed up.
What happens to Voyager has to do with some telemetry problem.
While the spacecraft continues to return science data and otherwise operate as normal, the
mission team is searching for the source of a system data issue.
It is actually some kind of a mystery: it seems that the interstellar explorer, Voyager
1, is operating normally: it is receiving and executing commands from Earth, and it
is also gathering and returning precious science data.
The only – but big – problem is that basically...we don't know where data is coming from.
Let me explain it better.
Readouts from the probe's orientation data, seem to suggest that...Voyager doesn't know
where it is. Not being able to orient a spacecraft in space
is a really bad thing. For example, among other things, it is vital for keeping the
antenna pointed precisely at Earth, enabling it to send data home.
If we were engineers, we would say that the readouts from the probe’s attitude articulation
and control system – the so-called AACS - don’t reflect what’s actually happening
onboard.
The AACS controls the 45-year-old spacecraft’s orientation.
All signs suggest the AACS is still working, but the telemetry data it’s returning is
invalid. For instance, the data may appear to be randomly generated or does not reflect
any possible state the AACS could be in.
Engineers are trying to understand what's the problem and how to solve it.
The thing is this is really a mystery because the issue doesn't seem to be huge.
I mean, no onboard fault protection systems were activated, and the spacecraft didn't
enter the safe mode, which is a state where only essential operations are carried out.
Everything seems to be completely fine, except the received data are kind of unphysical.
Also, the signal is perfectly fine: it hasn't weakened, and this suggests that the high
gain antenna can still point towards Earth.
Don't worry. Scientists are working on that. But until the nature of the issue is better
understood, the team said it can't guarantee anything about the spacecraft. This sort of
“glitch” could possibly be the beginning of the end for Voyager 1.
The fantastic probe, however, is currently 23.3 billion kilometres from Earth, and it
takes light 20 hours and 33 minutes to travel that difference. This means that, in order
to send a command, or get a response to it, or to collect data, there's a delay of about
one day. It's like every operation takes one day. This is a delay that accumulated over
time. For example, when Voyager was orbiting Jupiter, the delay was only 43 minutes. Over
time, the team got accustomed to this delay. “A mystery like this is sort of par for
the course at this stage of the Voyager mission,” said Suzanne Dodd, project manager for Voyager
1 and 2. “The spacecraft are both almost 45 years old, which is far beyond what the
mission planners anticipated. We’re also in interstellar space – a high-radiation
environment that no spacecraft have flown in before. So there are some big challenges
for the engineering team. But I think if there’s a way to solve this issue with the AACS, our
team will find it.”
If the team won't be able to find a solution to the anomaly, there's a high chance it will
have to adapt to it. This might be done with redundant hardware systems.
Most spacecraft have one or more hardware systems, maybe designed for different applications,
but in some specific (and problematic) cases, engineers can decide to switch off the malfunctioning
ones and to switch on the best ones left.
It wouldn’t be the first time the Voyager team has relied on backup hardware: In 2017,
Voyager 1’s primary thrusters showed signs of degradation, so engineers switched to another
set of thrusters that had originally been used during the spacecraft’s planetary encounters.
Those thrusters worked, despite having been unused for 37 years!
Before moving on, be sure to like or dislike the video so that we can continue to improve
and make these videos better for you the viewer. Plus, be sure to subscribe to the channel
by clicking the bell so that you don't miss ANY of our weekly videos."
Anyway, let's not focus only on the bad news! Voyager 1’s twin, Voyager 2 currently at
a distance of 19.5 billion kilometres, from Earth, continues to operate normally. And
it seems to have no problems.
As we've already said in the intro, both Voyagers have operated far longer than mission planners
expected, and are the only spacecraft to collect data in interstellar space.
They were launched in 1977, and the information they provided during all these years has helped
drive a deeper understanding of the heliosphere, the diffuse barrier the Sun creates around
the planets in our solar system.
While the engineers continue to work at solving the mystery that Voyager 1 has presented them,
the mission’s scientists will continue to make the most of the data coming down from
the spacecraft’s unique vantage point.
This said it would really be a shame if we lost Voyager 1 because we are attached to
it! After all, Voyager spacecrafts are record
holders!
For example, they are the third and fourth human spacecraft to fly beyond all the planets
in our solar system. Pioneers 10 and 11 preceded Voyager in outstripping the gravitational
attraction of the Sun but on February 17, 1998, Voyager 1 passed Pioneer 10 to become
the most distant human-made object in space.
Moreover, and this is something that not everybody knows, Voyager spacecrafts carry a greeting
to any form of life, should that be encountered.
The message is encrypted in a phonograph record. This is a gold-plated copper disk that contains
sounds and images selected to portray the diversity of life and culture on Earth.
The contents of the record were selected for NASA by a committee chaired by Carl Sagan
of Cornell University. Dr Sagan and his associates assembled 115 images and a variety of natural
sounds. To this, they added musical selections from different cultures and eras and spoken
greetings from Earth-people in fifty-five languages.
Just to mention another last record, Voyager's probes are the only human-made objects that
reached the heliosphere and the heliopause, entering the interstellar space.
In fact, the heliosphere is a sort of bubble around the Sun.
It is filled with the solar magnetic field and the protons and electrons of the solar
wind. The so-called heliopause marks the end of
the heliosphere and the beginning of interstellar space. Voyager 1, which is travelling up away
from the plane of the planets, entered interstellar space on Aug. 25, 2012. Voyager 2, which is
headed away from the sun beneath the plane of the planets, reached interstellar space
on Nov. 5, 2018.
Anyway, it's very sad to hear such bad news coming from Voyager 1, but we can stay positive
and think about it as an occasion of growth for our engineering systems.
Think about this: communication is not only a matter of satellites and probes. It is also
vitally important to astronauts while they are in space. This is not just because it
allows them to connect with their friends and family on Earth, but because it's the
main way of communication they have to speak to their team of experts on the ground. In
a nutshell, communication for an astronaut means safety.
Communication in low Earth orbit, where the International Space Station (ISS) orbits,
is almost instant. When travelling further into space, communication becomes a bit tricky.
Basically, if we are able to communicate with the Voyager probes, at a distance of 20 billion
kilometres, this means our astronauts will have zero problems when it comes to Moon or
Mars missions.
And solving problems of this kind, when they arise, means taking a step further toward
better communication systems.
Thanks for watching everyone! What do you guys think of Voyager 1 and 2?
Do you think engineers at NASA will be able to re-establish good telemetry for the spacecraft?
Let me know in the comments below, be sure to subscribe, and I'll see you next time on
the channel!