Voyager 2 is back online after eight months of radio silence
theregister.com
Voyager 2 is back online after eight months of radio silence
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Re: Voyager 2 is back online after eight months of radio silence
#2I don't think the Register's headline is very accurate. The probe itself remained online, and there was plenty of radio communication happening during that period; it was just one-way, from Voyager 2 to Earth. From NASA's press release:
> The call to Voyager 2 was a test of new hardware recently installed on Deep Space Station 43, the only dish in the world that can send commands to Voyager 2. ... Since the dish went offline, mission operators have been able to receive health updates and science data from Voyager 2, but they haven't been able to send commands to the far-flung probe, which has traveled billions of miles from Earth since its 1977 launch.
https://www.nasa.gov/feature/jpl/nasa-contacts-voyager-2-usi...
Re: Voyager 2 is back online after eight months of radio silence
#3I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn.
Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platform is a maddening predicament: knowing that the spacecraft is flying past wonders that have never been witnessed, that we will not see again for years or decades, and the incurious spacecraft staring fixedly off into space, ignoring everything.
The scan platform is driven by actuators containing gear trains. So first the JPL engineers ran an identical copy of a flight actuator in a simulated mission. This actuator failed after 348 turns; the actuator on the spacecraft had failed after 352 turns. The problem turned out to be a lubrication failure. Good to know, but what to do about it? Plainly, it would be impossible to overtake Voyager with an oilcan.
The engineers wondered whether they could restart the failed actuator by alternate heating and cooling; maybe the resulting thermal stresses would induce the components of the actuator to expand and contract at different rates and unjam the system. They tested this notion with specially manufactured actuators in the laboratory, and then jubilantly found that in this way they could start the scan platform up again in space. Project personnel also devised ways to diagnose any additional trend toward actuator failure early enough to work around the problem. Thereafter, Voyager 2’s scan platform worked perfectly. All the pictures taken in the Uranus and Neptune systems owe their existence to this work. The engineers had saved the day again.
Our hacks are nothing compared to the hacks of these old school nasa programmers :)
Re: Voyager 2 is back online after eight months of radio silence
#4I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
Our hacks are nothing compared to the hacks of these old school nasa programmers :)
The amazing thing (to me) is that they developed the Voyager spacecraft in an era when space flight wasn't hugely popular and the budgets at NASA were being cut regularly. NASA went from a peak of $6bn a year in the mid-sixties under Johnson to almost half that under Ford and Nixon. The engineers were well-respected and they clearly felt the work was important, but they weren't particularly well paid. They did this for the love and the science.
Re: Voyager 2 is back online after eight months of radio silence
#5I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
Our hacks are nothing compared to the hacks of these old school nasa programmers :) The amazing thing (to me) is that they developed the Voyager spacecraft in an era when space flight wasn't hugely popular and the budgets at NASA were being cut regularly. NASA went from a peak of $6bn a year in the mid-sixties under Johnson to almost half that under Ford and Nixon. The engineers were well-respected and they clearly f…
It's great, but hardly amazing. Most academic research is done by underpaid PhD and postdoc students for the love of science, and most of that is far less glamorous than SPACE.
Re: Voyager 2 is back online after eight months of radio silence
#6I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
I found out that usually happens when you have some constraints. The more constraints the more clever ways people find to achieve their goal.
Re: Voyager 2 is back online after eight months of radio silence
#7I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
It has become commonplace to solve hardware problems with software. But many times it is not for heroic reasons, it's because hardware is cost-reduced.
Re: Voyager 2 is back online after eight months of radio silence
#8"The probe launched on August 20th 1977, but is still just seventeen light-hours away"
43 years for 0.00194 light years... makes me feel :( huh ... and nearest star Proxima Centauri is 4.2441 light years away ... :/
Re: Voyager 2 is back online after eight months of radio silence
#9I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
I found out that usually happens when you have some constraints. The more constraints the more clever ways people find to achieve their goal.
Up until so much constraints than even the most clever give up.
Re: Voyager 2 is back online after eight months of radio silence
#10I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
I found out that usually happens when you have some constraints. The more constraints the more clever ways people find to achieve their goal.
It makes me think of the demoscene, that is doing things like getting 3D graphics on the Commodore or whatever it was.