- 4548 -
VOYAGER SPACECRAFT - they
just keep going? - The Voyager 1 spacecraft is sending back a
steady stream of scientific data from uncharted territory for the first time
since a computer glitch sidelined the historic NASA mission seven months ago.
------------------------------ 4548
- VOYAGER SPACECRAFT
- they just keep going?
-
- Currently the farthest spacecraft from
Earth, Voyager 1 stopped communicating coherently with mission control in
November 2023. The probe seemed caught up in a “Groundhog Day” scenario, with
its flight data system’s telemetry modulation unit sending back an
indecipherable repeating pattern of code from billions of miles away.
-
- A creative fix by the Voyager mission team
restored communication with the spacecraft, and engineering data began
streaming back to mission control in April, 2024, informing the team of the
spacecraft’s health and operational status.
-
- However, data from Voyager 1’s four science
instruments, which study plasma waves, magnetic fields and particles, was
missing. This information is important to show scientists how particles and
magnetic fields change as the probe flies farther away.
-
- On May 19, 2024, the Voyager team sent a
command to the spacecraft to start returning science data. Two of the
instruments responded, but getting data back from the other two took time, and
the instruments required recalibration. Now, all four instruments are beaming
back usable science data, according to an update shared by NASA on June 13.
-
- Voyager 1’s flight data system is
responsible for collecting information from the spacecraft’s science
instruments and bundling it with engineering data that reflects the probe’s
health status. Mission control on Earth, located at NASA’s Jet Propulsion
Laboratory (JPL) in Pasadena, California, receives that data in binary code, or
a series of ones and zeroes.
-
- It took time and some out-of-the-box
thinking for Voyager mission specialists to decode the spacecraft’s garbled
code. But once they did, they determined the cause of the issue: 3% of the
flight data system’s memory was corrupted.
-
- A single chip responsible for storing part
of the system’s memory, including some of the computer’s software code, isn’t
working properly and the loss of the code on the chip caused Voyager 1’s
science and engineering data to be unusable.
-
- Since there is no way to repair the chip,
the team stored the affected code from the chip elsewhere in the system’s
memory. They couldn’t pinpoint a location large enough to hold all the code, so
they divided it into sections and stored it in different spots within the
flight data system. There are still
minor fixes needed to manage the effects of the initial issue.
-
- Among other tasks, engineers will
resynchronize timekeeping software in the spacecraft’s three onboard computers
so they can execute commands at the right time.
The team will also perform maintenance on the digital tape recorder,
which records some data for the plasma wave instrument that is sent to Earth
twice per year.
-
- The spacecraft is currently about 15
billion miles away from Earth, while its sister vehicle, Voyager 2, has
traveled more than 12 billion miles from Earth. The twin probes lifted off
weeks apart in 1977, and after initially flying by Jupiter, Saturn, Uranus and
Neptune, their missions have been extended to 46 years and counting.
-
- Both are in interstellar space and the only
spacecraft to operate beyond the heliosphere, the sun’s bubble of magnetic
fields and particles that extends well beyond Pluto’s orbit. As the sole extensions of humanity outside
the heliosphere’s protective bubble, the two probes are alone on their cosmic
treks as they travel in different directions.
-
- Think of the planets of Earth’s solar
system as existing in one plane. Voyager 1’s trajectory took it up and out of
the plane after passing Saturn, while Voyager 2 passed over the top of Neptune
and moved down and out of the plane.
-
- The information collected by these
long-lived probes, the only two spacecraft to directly sample interstellar
space with their instruments, is helping scientists learn about the cometlike
shape of the heliosphere and how it protects Earth from energized particles and
radiation in interstellar space.
-
- Over time, both spacecraft have encountered
unexpected issues and dropouts, including a seven-month period in 2020 when
Voyager 2 couldn’t communicate with Earth. In August 2023, the mission team
used a long-shot “shout” technique to restore communications with Voyager 2
after a command inadvertently oriented the spacecraft’s antenna in the wrong
direction.
-
- We never know for sure what’s going to
happen with the Voyagers, but it is constantly amazes when they just keep going.
-
-
September 4, 2024 VOYAGER
SPACECRAFT - they just keep going? 4548
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--------------------- --- Thursday, September 5,
2024
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