Voyager 1 Team Accomplishes Tricky Thruster Swap (nasa.gov) 46
fjo3 shares a report from NASA: Engineers working on NASA's Voyager 1 probe have successfully mitigated an issue with the spacecraft's thrusters, which keep the distant explorer pointed at Earth so that it can receive commands, send engineering data, and provide the unique science data it is gathering. After 47 years, a fuel tube inside the thrusters has become clogged with silicon dioxide, a byproduct that appears with age from a rubber diaphragm in the spacecraft's fuel tank. The clogging reduces how efficiently the thrusters can generate force. After weeks of careful planning, the team switched the spacecraft to a different set of thrusters. [...]
Switching to different thrusters would have been a relatively simple operation for the mission in 1980 or even 2002. But the spacecraft's age has introduced new challenges, primarily related to power supply and temperature. The mission has turned off all non-essential onboard systems, including some heaters, on both spacecraft to conserve their gradually shrinking electrical power supply, which is generated by decaying plutonium. While those steps have worked to reduce power, they have also led to the spacecraft growing colder, an effect compounded by the loss of other non-essential systems that produced heat. Consequently, the attitude propulsion thruster branches have grown cold, and turning them on in that state could damage them, making the thrusters unusable.
The team determined that the best option would be to warm the thrusters before the switch by turning on what had been deemed non-essential heaters. However, as with so many challenges the Voyager team has faced, this presented a puzzle: The spacecraft's power supply is so low that turning on non-essential heaters would require the mission to turn off something else to provide the heaters adequate electricity, and everything that's currently operating is considered essential. Studying the issue, they ruled out turning off one of the still-operating science instruments for a limited time because there's a risk that the instrument would not come back online. After additional study and planning, the engineering team determined they could safely turn off one of the spacecraft's main heaters for up to an hour, freeing up enough power to turn on the thruster heaters. It worked. On Aug. 27, they confirmed that the needed thruster branch was back in action, helping point Voyager 1 toward Earth.
Switching to different thrusters would have been a relatively simple operation for the mission in 1980 or even 2002. But the spacecraft's age has introduced new challenges, primarily related to power supply and temperature. The mission has turned off all non-essential onboard systems, including some heaters, on both spacecraft to conserve their gradually shrinking electrical power supply, which is generated by decaying plutonium. While those steps have worked to reduce power, they have also led to the spacecraft growing colder, an effect compounded by the loss of other non-essential systems that produced heat. Consequently, the attitude propulsion thruster branches have grown cold, and turning them on in that state could damage them, making the thrusters unusable.
The team determined that the best option would be to warm the thrusters before the switch by turning on what had been deemed non-essential heaters. However, as with so many challenges the Voyager team has faced, this presented a puzzle: The spacecraft's power supply is so low that turning on non-essential heaters would require the mission to turn off something else to provide the heaters adequate electricity, and everything that's currently operating is considered essential. Studying the issue, they ruled out turning off one of the still-operating science instruments for a limited time because there's a risk that the instrument would not come back online. After additional study and planning, the engineering team determined they could safely turn off one of the spacecraft's main heaters for up to an hour, freeing up enough power to turn on the thruster heaters. It worked. On Aug. 27, they confirmed that the needed thruster branch was back in action, helping point Voyager 1 toward Earth.
Fuck yeah, Slashdot! (Score:5, Insightful)
Nerd shit.
Thanks for sharing. Glad we still have the resources to support these efforts after half a century. That alone, is an accomplishment.
Re: Fuck yeah, Slashdot! (Score:5, Insightful)
Re:Fuck yeah, Slashdot! (Score:5, Insightful)
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Even with reposts? /s
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Amazing is, that the original engineers put so many options into the crafts, to "change the runtime configuration on the fly"!
And that it is well documented, that our days youngsters, actually can do it.
Engineering at its finest (Score:5, Insightful)
Engineering at its finest. I am still so impressed whenever they manage a manoeuvre or a change in the setup of that 50 year old spacecraft at a distance of some 25 billion km.
Re:Engineering at its finest (Score:5, Insightful)
People wonder why NASA is so expensive and its programs cost so much compared to the likes of SpaceX.
This is why. A 50yo spaceship that refuses to die.
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People wonder why NASA is so expensive and its programs cost so much compared to the likes of SpaceX.
This is why. A 50yo spaceship that refuses to die.
I'd wager that the expense of the level of redundancy they build in, the extensive code reviews, etc is dwarfed by the expense of choosing suppliers based on congressional district and other similar graft. Also, a counterpoint to this is "SLS" which has all of the expense and none of the engineering quality.
Re:Engineering at its finest (Score:5, Informative)
People wonder why NASA is so expensive and its programs cost so much compared to the likes of SpaceX.
This is why. A 50yo spaceship that refuses to die.
I would not call Voyager "expensive" in the Boeing subcontracting or DOD subcontracting sense. From NASA:
The total cost of the Voyager mission from May 1972 through the Neptune encounter (including launch vehicles, radioactive power source (RTGs), and DSN tracking support) is 865 million dollars.
This is like $5 billion in today's dollars, which, I think, is less than what Boeing has spent on the starliner that they can't get right. And Voyager was state of the art - everything was new tech, SpaceX had the advantage of the existing advanced computer and space tech. Boeing had it too, but they are just useless nowadays...
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Part of the reason for its survival is that they really didn't know what was out there, so they had to overbuild to compensate for the "unknown unknowns". Interplanetary space and now extra-solar system space seem to be less problematic than anticipated, fortunately.
The little craft that can (Score:3)
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Yeah I was 3 years and a day. fucking things almost as old as me lol. BTW belated happy birthday
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I was almost 14, tadpoles.
Can still remember Sagan explaining what the craft's mission was on launch day.
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,br>I'm happy you've been through therapy enough to chat casually about it, but maybe Slashdot isn't the place for that kind of conversation.
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I wasn't even a shine in my father's eyes...
Very impressive. (Score:2)
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Had a girlfriend once who said almost the same thing as her reason for not wanting to have sex on the beach.
Wow! How? (Score:3, Interesting)
This is amazing. How is it possible? What's to be learned here? Is the design just solid and simple? Back on earth there appears to be an entropy risk in engineering products, adding features, nice to have, but only incremental improvements to core function and shorter lifespans. We end up with something complex performing a simple function. An IoT washing machine that lasts for a year.
NASA must have a detailed simulation model of voyager to figure these plans out. How could they tell it was a pipe furring up?
Impressive. Go Humans!
Re: Wow! How? (Score:3, Interesting)
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How could they tell it was a pipe furring up?
Measuring expected and actual thrust from firings, and then running through a root cause analysis when those numbers started not matching up.
"Cold Space" (Score:5, Interesting)
I was raised with the knowledge that space is near absolute zero, which is cold, so I presumed that keeping things warm in space would be quite difficult.
Then I met a guy who designed radiators for NASA.
Since there is no conduction or convection in space, all the calculations are based on radiation, from the craft and the sun.
So what I get from this nice writeup is that Voyager has an allowable temperature range and that over an hour it will cool (radiate) to the lower end of that range, when they will turn back on the main heaters.
Presumably the craft will then very slowly warm back to the current ideal temperature and the thruster system will be warm enough to use.
I do wonder about the NASA system and if they have one old legend who let them know that if they're firing up those thrusters they better preheat it so nothing cracks.
The 70's may have been they heyday of raw American engineering talent.
They sure don't make 'em like they used to!
Re: "Cold Space" (Score:2)
Im betting the preheat is also in the operating procedure and that's how they knew about it. I'd be hard pressed to believe there's anything about NASA that runs on tribal knowledge. Procedures for procedures seems clunky but it's for this exact situation where it is absolutely critical to follow all the steps.
That's not to discount experience though, experience is extremely valuable. Experience is what feeds the procedures and gives them meaning and background. Without experience, procedures become instruc
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A lot of the folks on the team who have retired regularly update NASA with their current contact information just so that they can be queried for this sort of oddball thing. No idea if that happened this time, but it's good to know that people are still available half a century later to take a call.
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The heart of Voyager is the black ten-sided box under the main antenna. The ten-sided box is a ring, with compartments on the periphery that contain the electronics, the transmitters, etc. In the middle of that ring sits the (spherical) fuel tank.
That black stuff is insulation. Most, if not all of the inside is heated. The computers are around 0 ÂC. The fuel tank is kept above the freezing point of the fuel.
Each of the instruments has its own heater. They've been switching some of these off, with instr
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JFHC. Slashdot has always had problems with Dunning Kruger, but this is pathetic. "Space" is NOT COLD. Space is a (near) vacuum. Cold is a concept from thermodynamics that matter will has an internal degree of freedom which is molecules bounding around. When two gasses combine, they will find a common temperature based on temp difference, amount of gas, and a bunch of things. Similarly for liquids and solids. Did I mention that space is a vacuum? IT IS NOT COLD AND DOES MAKE THINGS COLD. As a matte
Amazing (Score:2)
It's amazing that this is still going.
I imagine it would be difficult to replicate it's longevity. I imagine funding for NASA was pretty good when this was first started (it being nearer to the era the space race). Also, most supply chains seem to have built in obsolescence now, and I don't think that was the case or, at the very least, as common. Today's parts/equipment may be more efficient, but it's not long lasting e.g air conditioners/heaters, refrigerators, washer and dryers etc. Commercial supply c
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Re:Amazing (Score:5, Informative)
I imagine it would be difficult to replicate it's longevity
I don't know about that. There have been many recent missions that have far, far exceeded their designs and are arguably more impressive than Voyager.
Examples...
Mars Rover Opportunity was expected to function 90 days by design. It functioned 59 times longer than that (15 years / over 5300 days), and drove over 28 miles on the surface, setting the record for the most distance traveled off-planet by any craft.
Ingenuity was the first aircraft to fly off-planet. The goal was to fly 5 times, assuming it would fly at all and not crash immediately, and the mission was simply to get some metrics about how to fly in that atmosphere. It was intended to fly a few hundred yards is all, and was expected to crash at the end of the final flight. It performed so amazingly well that it flew 72 times over a total distance of 11 miles, and was so useful they began using it to scout ahead and capture data used to determine where to drive the rover. It literally went from a little side tech demo to a massively useful part of the entire mission. Fun side note... it actually has an FAA registration like other aircraft on Earth, registration number IGY.
There have been other rovers and missions lately (Curiosity and Perseverance for example) that have similarly performed phenomenally well, so happily it seems Nasa is continuing the tradition established back in the Voyager era.
The Voyagers are awesome! (Score:2)
Every time I read news about breakthroughs in the Voyagers I feel happy and excited. These ships are awesome and, for me, truly the symbol of technology and craftsmanship.
Impressed (Score:4, Insightful)
It's hard to say which I'm most impressed with - the engineers that designed this thing, or the grandchildren of the engineers that are figuring out how to keep it functioning.
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Survivor Fallacy (Score:2)
Most impressive engineering support feat ever? (Score:2)
Re: Most impressive engineering support feat ever? (Score:1)
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Apollo 13 was also a lesson in the importance of standardization of system components where possible - having to duct tape a square carbon dioxide filter into a round receptacle just because they were made by different vendors, instead of using standardized filters throughout the whole project almost led to disaster for the troubled mission.
Unfortunately that lesson still doesn't seem to have been fully learnt, as indicated with the recent issue of the spacesuits used for Starliner not having compatible con
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Then there was the Mars Climate Orbiter, lost because JPL and everyone else at NASA use metric measurements, but the morons at Lockheed used Imperial.
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Yana Machu (Quechua for 'Old Black'), a 102 year old Baldwin steam engine, was retired just a few years ago from the Peruvian rail system where it had been in continual use since its manufacture (the last 30 as a switching engine and tug for the Cusco section) and placed in a park ear the airport.
There is a lot of ancient hardware out there in use just because "If it ain't broke don't fix it" is such a good piece of advice. There is a 1930s Harley Davidson motorcycle motor running irrigation pumps for a fa