Voyager 1 Signals from Interstellar Space Detected by Amateur Astronomers on 1950s Telescope (gizmodo.com) 22
"Voyager 1 is currently exploring interstellar space at a distance of 15.5 billion miles (24.9 billion kilometers) away from Earth," writes Gizmodo.
And yet a team of amateur astronomers in the Netherlands was able to receive Voyager's signals on a 1950s telescope designed to detect weak, low-frequency emissions from deep space: NASA uses the [Earth-based] Deep Space Network (DSN) to communicate with its spacecraft, but the global array of giant radio antennas is optimized for higher frequency signals. Though NASA's DSN antennas are capable of detecting S-band missives from Voyager — it can also communicate in X-band — the spacecraft's signal can appear to drop due to how far Voyager is from Earth. The Dwingeloo telescope, on the other hand, is designed for observing at lower frequencies than the 8.4 gigahertz telemetry transmitted by Voyager 1, according to the C.A. Muller Radio Astronomy Station... [W]hen Voyager 1 switched to a lower frequency, its messages fell within Dwingeloo's frequency band. Thus, the astronomers took advantage of the spacecraft's communication glitch to listen in on its faint signals to NASA.
The astronomers used orbital predictions of Voyager 1's position in space to correct for the Doppler shift in frequency caused by the motion of Earth, as well as the motion of the spacecraft through space. The weak signal was found live, and further analysis later confirmed that it corresponded to the position of Voyager 1. Thankfully, the mission team at NASA turned Voyager 1's X-band transmitter back on in November, and is currently carrying out a few remaining tasks to get the spacecraft back to its regular state. Fortunately, radio telescopes like Dwingeloo can help fill in the gaps while NASA's communications array has trouble reaching its spacecraft.
Scientific American shares an interesting perspective on the Voyager probes: we everyday Earthlings may simplistically think of the sun as a compact distant ball of light, in part because our plush atmosphere protects us from our star's worst hazards. But in reality the sun is a roiling mass of plasma and magnetism radiating itself across billions of miles in the form of the solar wind, which is a constant stream of charged plasma that flows off our star. The sun's magnetic field travels with the solar wind and also influences the space between planets. The heliosphere grows and shrinks in response to changes in the sun's activity levels over the course of an 11-year cycle... [Jamie Rankin, a space physicist at Princeton University and deputy project scientist of the Voyager mission] notes, astronomers of all stripes are trapped within that chaotic background in ways that may or may not affect their data and interpretations. "Every one of our measurements to date, until the Voyagers crossed the heliopause, has been filtered through all the different layers of the sun," Rankin says.
On their trek to interstellar space, the Voyagers had to cross a set of boundaries: first a termination shock some seven billion or eight billion miles away from the sun, where the solar wind abruptly begins to slow, then the heliopause, where the outward pressure from the solar wind is equaled by the inward pressure of the interstellar medium. Between these two stark borders lies the heliosheath, a region where solar material continues to slow and even reverse direction. The trek through these boundaries took Voyager 1, the faster of the twin probes, nearly eight years; such is the vastness of the scale at play.
Beyond the heliopause is interstellar space, which Voyager 1 entered in 2012 and Voyager 2 reached in 2018. It's a very different environment from the one inside our heliosphere — quieter but hardly quiescent. "It's a relic of the environment the solar system was born out of," Rankin says of the interstellar medium. Within it are energetic atomic fragments called galactic cosmic rays, as well as dust expelled by dying stars across the universe's eons, among other ingredient.
Earlier this month Wired noted " The secret of the Voyagers lies in their atomic hearts: both are equipped with three radioisotope thermoelectric generators, or RTGs — small power generators that can produce power directly on board. Each RTG contains 24 plutonium-238 oxide spheres with a total mass of 4.5 kilograms..." But as time passes, the plutonium on board is depleted, and so the RTGs produce less and less energy. The Voyagers are therefore slowly dying. Nuclear batteries have a maximum lifespan of 60 years. In order to conserve the probes' remaining energy, the mission team is gradually shutting down the various instruments on the probes that are still active...
Four active instruments remain, including a magnetometer as well as other instruments used to study the galactic environment, with its cosmic rays and interstellar magnetic field. But these are in their last years. In the next decade — it's hard to say exactly when — the batteries of both probes will be drained forever.
And yet a team of amateur astronomers in the Netherlands was able to receive Voyager's signals on a 1950s telescope designed to detect weak, low-frequency emissions from deep space: NASA uses the [Earth-based] Deep Space Network (DSN) to communicate with its spacecraft, but the global array of giant radio antennas is optimized for higher frequency signals. Though NASA's DSN antennas are capable of detecting S-band missives from Voyager — it can also communicate in X-band — the spacecraft's signal can appear to drop due to how far Voyager is from Earth. The Dwingeloo telescope, on the other hand, is designed for observing at lower frequencies than the 8.4 gigahertz telemetry transmitted by Voyager 1, according to the C.A. Muller Radio Astronomy Station... [W]hen Voyager 1 switched to a lower frequency, its messages fell within Dwingeloo's frequency band. Thus, the astronomers took advantage of the spacecraft's communication glitch to listen in on its faint signals to NASA.
The astronomers used orbital predictions of Voyager 1's position in space to correct for the Doppler shift in frequency caused by the motion of Earth, as well as the motion of the spacecraft through space. The weak signal was found live, and further analysis later confirmed that it corresponded to the position of Voyager 1. Thankfully, the mission team at NASA turned Voyager 1's X-band transmitter back on in November, and is currently carrying out a few remaining tasks to get the spacecraft back to its regular state. Fortunately, radio telescopes like Dwingeloo can help fill in the gaps while NASA's communications array has trouble reaching its spacecraft.
Scientific American shares an interesting perspective on the Voyager probes: we everyday Earthlings may simplistically think of the sun as a compact distant ball of light, in part because our plush atmosphere protects us from our star's worst hazards. But in reality the sun is a roiling mass of plasma and magnetism radiating itself across billions of miles in the form of the solar wind, which is a constant stream of charged plasma that flows off our star. The sun's magnetic field travels with the solar wind and also influences the space between planets. The heliosphere grows and shrinks in response to changes in the sun's activity levels over the course of an 11-year cycle... [Jamie Rankin, a space physicist at Princeton University and deputy project scientist of the Voyager mission] notes, astronomers of all stripes are trapped within that chaotic background in ways that may or may not affect their data and interpretations. "Every one of our measurements to date, until the Voyagers crossed the heliopause, has been filtered through all the different layers of the sun," Rankin says.
On their trek to interstellar space, the Voyagers had to cross a set of boundaries: first a termination shock some seven billion or eight billion miles away from the sun, where the solar wind abruptly begins to slow, then the heliopause, where the outward pressure from the solar wind is equaled by the inward pressure of the interstellar medium. Between these two stark borders lies the heliosheath, a region where solar material continues to slow and even reverse direction. The trek through these boundaries took Voyager 1, the faster of the twin probes, nearly eight years; such is the vastness of the scale at play.
Beyond the heliopause is interstellar space, which Voyager 1 entered in 2012 and Voyager 2 reached in 2018. It's a very different environment from the one inside our heliosphere — quieter but hardly quiescent. "It's a relic of the environment the solar system was born out of," Rankin says of the interstellar medium. Within it are energetic atomic fragments called galactic cosmic rays, as well as dust expelled by dying stars across the universe's eons, among other ingredient.
Earlier this month Wired noted " The secret of the Voyagers lies in their atomic hearts: both are equipped with three radioisotope thermoelectric generators, or RTGs — small power generators that can produce power directly on board. Each RTG contains 24 plutonium-238 oxide spheres with a total mass of 4.5 kilograms..." But as time passes, the plutonium on board is depleted, and so the RTGs produce less and less energy. The Voyagers are therefore slowly dying. Nuclear batteries have a maximum lifespan of 60 years. In order to conserve the probes' remaining energy, the mission team is gradually shutting down the various instruments on the probes that are still active...
Four active instruments remain, including a magnetometer as well as other instruments used to study the galactic environment, with its cosmic rays and interstellar magnetic field. But these are in their last years. In the next decade — it's hard to say exactly when — the batteries of both probes will be drained forever.
In flight refuelling (Score:3)
While nobody wants to wait around for another Grand Tour alignment, it shouldn't be too long before we could launch an inertial confinement fusion rocket that could catch up to a Voyager probe.
Of course, matching velocity without pointing your fusion exhaust at the poor thing would be a small challenge compared to trying to replace the power source on a probe that wasn't designed to be worked on in flight.
And of course, once you CAN do that... you wouldn't bother because it would be much better just to send a whole bunch of new instrumentation out there on that fusion rocket and get it out further, faster.
Poor Voyager probes, abandoned to the void.
Re: In flight refuelling (Score:2)
Lol, don't ever change! You're hilarious.
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Poor Voyager probes, abandoned to the void.
Poor Voyager probes? NASA wasn't sure if they were going to make it through the asteroid belt. Then their original mission length was 3 years for Voyager 1 and 5 years for Voyager 2. Here we are almost 50 years later and they're still collecting scientific data on hardware that looks like it's from the stone age compared to what some 7 year old kids have in their pocket. Or parents use to entertain their toddler with baby shark videos. Most tech from that era was sent to the landfill decades ago. Those prob
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Poor in that we can't make them last even longer. Poor in that we can't bring them home and put them in a museum (even though that would shorten their existence drastically).
But yeah, awesome probes, awesome project, one of humanity's greatest achievement so far really.
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We don't need a Grand Tour, just send individual probes -- maybe ones with landers. We can do it with today tech, without waiting for fusion to be viable.
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We started doing that right after Voyager: Galileo and Cassini were built specifically to answer the questions about Jupiter and Saturn that the Voyager data raised.
Orbiters for Uranus and Neptune are being studied at the moment; they have only recently become feasible thanks to advances in reducing launch cost.
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It's interesting to reflect on how modern hardware would have performed.
Faster, sure. Smaller, sure. Less power, sure. But would it survive in space? Given how small the elements are, wouldn't the occasional cosmic ray destroy sufficient elements to kill the whole gadget?
I have a sneaking suspicion a modern processor would be dead within months, or possibly years - but surviving decades?
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More modern processors have survived for decades: Cassini, launched in 1997, operated for 19 years until its fuel ran out.
Today's radiation-hardened processors are built using much larger feature sizes than consumer processors, and are being used for decades in Earth's van Allen belts, which have far higher radiation levels than the surrounding space.
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JHUAPL has done a study for an interstellar mission [jhuapl.edu] which uses current technology only to get a spacecraft up to a speed of 7 AU per year, or twice the speed of the Voyagers.
Wonder what minimum power level is for probe (Score:2)
"In order to conserve the probes' remaining energy"
Small nitpick here is that you cannot really conserve the nuclear batteries, they simply offer less power over time as the plutonium continues to be lost to decay, and the probe just has lower and lower amounts of power it can make use of.
It makes me wonder if the rated 60 years of battery life is really the floor, or if the probe can operate beyond that time with significantly reduced power from the batteries.
I found some interesting calculations on RTG ba
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voyager love us long time
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"...which notes that Voyager batteries are decaying at a fixed rate of 1.7% per year, and are currently at 67% of the initial power provided. So how much longer can the Voyager's systems live as the power drops...
The last thing working will be the cigarette lighter in the dash.
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Some of the instruments would continue to work for quite a while, but the comm system would not be able to send the results back. IIRC it's the single most power-hungry device on the spacecraft.
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They have to pick and choose which scientific instruments and/or heaters to shut off if they want enough power to run instruments at any one time as the power fades. And if some instruments get too cold, they may stop working. I believe they rotate the heater on some instruments/computers/transmitters to spread the risk.
But they are going have to switch off more instruments and heaters over time as the RTG gradually cools.
Nobody knows. T
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They're already past the floor, or where the floor was initially thought to be. A few years ago, they started to switch off heaters on the instruments that were still in operation. To the team's surprise, the instruments continued to work, despite being 60Â C colder than they were designed for.
They've removed voltage regulators from the circuit. This gave them another few W of margin.
There are a few ways the mission can end:
1. Power drops until the RTG can no longer power a single instrument. This will
50 years, 15.5 Billion Miles... (Score:3)
...and I still have to buy a new electric razor every four.
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Heh. Though I imagine if you spent a couple of million bucks on it, it'd have some longevity.
25m radio telescope (Score:2)
That looks cool. I bet I could build that for under $1 million and with one or two years of effort.
Radio astronomy pioneer (Score:2)
The Dwingeloo telescope [camras.nl] was the largest in the world when it was built in 1955. It held that title until Jodrell Bank came online in 1957.
After World War II, Dutch astronomers led by Jan Oort got hold of a German Wurzburg Riese radar antenna, and repurposed it for radio astronomy. In 1951, they managed to detect hydrogen radio emissions at the 21 cm wavelength. They used this telescope to map the hydrogen in the Milky Way, creating the first map of our galaxy.
This success led to money being made available f