VOYAGER 1 Have Fixed Problems And is Back fully operative!
Hey! Not so long ago, we posted a video about Voyager 1.
We said there were some problems, which were not compromising the overall mission, but
they had to be solved. These problems concerned the so-called AACS
instrument onboard the spacecraft: basically, engineers noticed they were receiving bad,
bad data from the probe. It didn't really reflect what was actually happening onboard.
Launched in 1977, both Voyagers have operated far longer than mission planners expected,
and are the only spacecraft to collect data in interstellar space. The information they
provide from this region has helped drive a deeper understanding of the heliosphere,
and the diffuse barrier the Sun creates around the planets in our solar system, so they provide
us with very important pieces of information.
The AACS instrument onboard Voyager 1 wasn't working properly, and they had to fix this
problem as soon as possible. After some time, the team finally figured
out what was going wrong. It was a networking problem.
But what is that? And how did they fix it?
Follow me in this video to get to know the answer to these questions, and more!
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In modern society, computers are heavily relied on for daily tasks and entertainment. You
just need to say “Hey google!”, or “Hey Siri”, and you have the whole world in one
hand.
Nowadays, most people think they know everything there is to know about computers and the technology
behind them. These objects have made a great impact on us all. They seem to be perfect
tools, but sometimes they happen to fail, and if they can't be fixed, we can, and we
should put them to sleep...forever!
The thing is – computers fail because they are human-made objects. And humans are not
perfect, which means laptops, smartphones, robots, and all that kind of stuff are most
likely destined to fail, sooner or later.
When it comes to space science and exploration, scientists always make sure to build and use
the best hardware they have, and most of the time what is brought to space is technology
at its best. But, as you can see, issues often arise, and engineers have to fix the problem,
or the mission will fail.
This is of course part of the mission itself, and it is what we call the “troubleshooting”
part. Take, for example, Artemis 1 mission. People from all over the world couldn't wait
for it to be launched on Aug 29, 2022. What happened instead? NASA wasn't able to fix
some problems right before liftoff, so the launch was scrubbed.
Problems like this happen all the time, but some of them are more subtle, and harder to
spot, even harder to solve, than others.
In the case of Voyager 1 the AACS (attitude articulation and control system), responsible
for maintaining the spacecraft orientation, was sending out data to Earth.
The only – but big – problem was that basically...we didn't know where this data
was coming from.
Let me explain it better.
Readouts from the probe's orientation data seemed to suggest that Voyager didn't know
where it was. 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 is what controls the 45-year-old spacecraft’s orientation and it was...speaking
a weird language.
Engineers couldn't really understand why, but they had to solve the problem as soon
as possible because the AACS was giving them precious information about the mission. It
was providing them with telemetry.
Telemetry is the in situ collections of measurements or other data at remote points and their automatic
transmission to receiving equipment (telecommunication) for monitoring. This word comes from the greek
roots “tele” - remote – and “metron” - measure.
Without telemetry, our spacecraft travels blindly in the universe.
The garbled data meant that Voyager 1 was communicating information about its location
and orientation that didn’t match up with the possible true location and orientation
of the spacecraft. Otherwise, the probe was behaving normally, as was its twin, Voyager
2. Both spacecraft launched in the summer of 1977, and Voyager 1 is the farthest human-made
object in the universe.
These probes are in interstellar space – a high-radiation environment that no spacecraft
have flown in before.
But finally, after some time, engineers found and solved the problem.
What happened was that the system began sending the telemetry back to Earth through a faulty
computer aboard Voyager 1, and the computer corrupted the information before it could
be read out from the team on Earth.
See? I told you! Computers are not perfect machines!
Thank God, engineers are good at problem-solving.
This “networking problem” is similar in spirit to something IT professionals might
face here on Earth. Essentially, the AACS was sending telemetry data all right, but
it was routing it to the wrong computer.
It took a while for the team to figure out the problem, and it wasn’t clear why AACS
suddenly began routing data to the wrong computer. Maybe it received a faulty command from another
computer. That implies there’s a problem somewhere else that they’ll have to solve.
But, so far, the issues are not a threat to the spacecraft.
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Suzanne Dodd, Voyager’s current project manager, said that once the engineers figured
out that the dead computer might have been part of the problem, they had a way forward.
They simply solved the problem by telling AACS to switch over sending to the correct
computer system. And it worked!
“We’re happy to have the telemetry back,” said Dodd.
“We’ll do a full memory readout of the AACS and look at everything it’s been doing.
That will help us try to diagnose the problem that caused the telemetry issue in the first
place. So we’re cautiously optimistic, but we still have more investigating to do.”
Luckily enough, the annoying issue with AACS didn’t set off any fault protection systems
onboard the spacecraft.
If it had, Voyager 1 would have gone into “safe mode”. Safe mode is an operating
mode of a modern unmanned spacecraft during which all non-essential systems are shut down
and only essential functions such as thermal management, radio reception, and attitude
control are active. The process of entering safe mode sometimes referred to as "safing",
involves a number of immediate physical actions taken to prevent damage or complete loss.
Power is removed from non-essential subsystems. Regaining attitude control, if lost, is the
highest priority because it is necessary to maintain thermal balance and proper illumination
of the solar panels.
However, entering safe mode does not mean the mission is compromised.
A lot of spacecraft entered safe mode. For instance, New Horizons in 2007, due to an
uncorrectable memory error in the primary command and data handling computer; or maybe
Kepler space telescope, that was triggered by an onboard processor reset twice in 2009.
Even the Hubble Space Telescope entered safe mode. It was October 2018, and it went safe
after one of its three active gyroscopes failed. At any given time, Hubble needs three of its
six gyroscopes operating to ensure optimal efficiency. In August 2005, Hubble began operating
in a new two-gyro mode to extend the telescope’s life and ensure it had at least two functioning
gyroscopes until Servicing Mission 4. Although the telescope can operate on only one gyroscope
if needed, the regions of the sky that are on view are limited.
Within years after the last servicing missions Hubble lost three gyroscopes (all of an older
design) till October 2018.
And then, Hubble went safe again in 2021. In that case, science observations were temporarily
suspended.
Last but not least, the Mars dust storm caused Opportunity Rover to enter safe mode on 13
June 2018. The rover was alimented by solar panels, but the dust storm made the atmosphere
so opaque, that almost all sunlight was blocked: the rover was unable to recharge its batteries.
In this case, this also brought the Opportunity mission to an end: on February 13, 2019, NASA
declared the mission was complete after the spacecraft had failed to respond to over 1,000
signals sent since August 2018.
But don't despair! During the period of garbled signals, Voyager 1's AACS continued working,
which indicated that the problem was either upstream or downstream of the unit. The fact
that data were garbled provided a good clue to related computer issues.
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Well, what can I say? So far so good!
We are happy to hear good news. The twin Voyager 1 and 2 spacecraft 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.
They are record holders: 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, a place where no other human-made spacecraft has ever flown before.
Voyager 2 entered this region sometime later, on Nov 2018. Both spacecraft are still sending
scientific information about their surroundings through the Deep Space Network, or DSN.
The primary mission was the exploration of Jupiter and Saturn.
The closest approach to Jupiter occurred on March 5, 1979, for Voyager 1.
The closest distance to Saturn was reached by Voyager 1 on November 1980.
Here are some amazing snapshots taken during these flybys. Aren't they amazing?
The Voyager spacecraft 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.
The Voyager mission also provided us with this beautiful narrow-angle color image of
the Earth, dubbed “pale blue dot”.
This is a part of the first ever 'portrait'
( of the solar system taken by Voyager 1.
The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance
of more than 4 billion miles from Earth.
This video ends here! Are you happy? Voyager 1 is still working properly!
Let us know how excited you are in the comments below!
And if you enjoyed the video, don't forget to share it, and I'll see you next time on
the channel.