Voyager 2 is back online after eight months of radio silence • Hacker News Board

Re: Voyager 2 is back online after eight months of radio silence

#61

Post by onion2k » Tue, Nov 03, 2020, 2:53 PM UTC

melling wrote: post #59

onion2k wrote: post #4

Earlier quoted context omitted.

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…

We spent more money under Nixon and Ford than we do now. You’re not familiar with how much money as a percentage of GDP we spent in the 1960s? It’s noteworthy. https://en.m.wikipedia.org/wiki/Budget_of_NASA#Annual_budget We were building the Space Shuttle and exploring the planets. I wish we could spend money on NASA like we did in the 1970’s

I wish we could spend money on NASA like we did in the 1970’s

I absolutely agree. It's far worse now. And, not at all coincidently, NASA is doing much less science now. A return to the 70s budget by GDP would be good, but a return to the 60s budget by GDP would be even better.

Re: Voyager 2 is back online after eight months of radio silence

#62

Post by Kye » Tue, Nov 03, 2020, 2:55 PM UTC

ponker wrote: post #22

superasn wrote: post #3

I 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…

They didn't even spin something 350 times before launching it out of the solar system?

It's remarkable to see people doing the usual "well this could obviously have been avoided by..." on something still functioning after 43 years and almost 12 billion miles from home in the most hazardous environment known to humans.

They did an absolutely amazing job and I take it as a given that this was not some novice mistake.

Re: Voyager 2 is back online after eight months of radio silence

#63

Post by shireboy » Tue, Nov 03, 2020, 2:56 PM UTC

"Which will be just in time for the arrival of the Perseverance Rover on Mars, another mission DSS43 will handle"

Wait, so they sent Perserverance on it's way to Mars without comms in the southern hemisphere? Or is this a backup?

Re: Voyager 2 is back online after eight months of radio silence

#64

Post by onion2k » Tue, Nov 03, 2020, 2:57 PM UTC

prox wrote: post #18

Cthulhu_ wrote: post #10

Earlier quoted context omitted.

It makes me think of the demoscene, that is doing things like getting 3D graphics on the Commodore or whatever it was.

Future Crew - Second Reality

Check out Zarch on the Acorn Archimedes. https://www.youtube.com/watch?v=MNXypBxNGMo It's an awesome 3D game from 1987 (with truly awful sound). That was made 6 years before Second Reality, on a RISC-based computer. It's incredible.

Re: Voyager 2 is back online after eight months of radio silence

#65

Post by NKosmatos » Tue, Nov 03, 2020, 3:01 PM UTC

It's only fitting to put a link to the Deep Space Network (DSN), displaying what all the dishes are doing right now (spacecrafts, data rates...): https://eyes.nasa.gov/dsn/dsn.html

Re: Voyager 2 is back online after eight months of radio silence

#66

Post by radiorental » Tue, Nov 03, 2020, 3:04 PM UTC

m463 wrote: post #7

superasn wrote: post #3

I 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.

I'm not sure I'd agree with that at all. On the surface of this planet software is used to simulate hardware as it's much quicker to iterate on a design.

In space, however, you can only run the hardware in it's destined environment once. Software is critical to the design process regardless of the HW costs.

Re: Voyager 2 is back online after eight months of radio silence

#67

Post by tduberne » Tue, Nov 03, 2020, 3:10 PM UTC

NiceWayToDoIT wrote: post #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 ... :/

That's funny, I had exactly the opposite reaction. Almost 20 light hours sounds far for something we basically strapped on the top of a big firecracker, which probably provided propulsion for at most a few dozen minutes... The fact that it was even possible to make that thing fly over several planets before exiting the orbital plane on a predictable course, and that one can still communicate with it as it exits the heliosphere is truly awe inspiring to me.

Re: Voyager 2 is back online after eight months of radio silence

#68

Post by Denvercoder9 » Tue, Nov 03, 2020, 3:10 PM UTC

shireboy wrote: post #63

"Which will be just in time for the arrival of the Perseverance Rover on Mars, another mission DSS43 will handle" Wait, so they sent Perserverance on it's way to Mars without comms in the southern hemisphere? Or is this a backup?

The Mars rovers, including Perserverance, usually communicate directly over a high-speed link with one of several relay satellites orbiting Mars. The smaller antennas of the DSN can communicate with the relay satellites as well.

Furthermore, the locations of the stations aren't determined by the hemispheres. Everything DSN is used for is far enough away from Earth that it doesn't matter if the antenna is in the northern or southern hemisphere. The reason for the spread-out stations is the rotation of the Earth, which for half of the day puts the Earth in between the station and the satellite.

Re: Voyager 2 is back online after eight months of radio silence

#69

Post by moftz » Tue, Nov 03, 2020, 3:34 PM UTC

Hnrobert42 wrote: post #45

frank2 wrote: post #40

Earlier quoted context omitted.

But a duplicate of the actuator failed in a lab on Earth after almost exactly as many turns as the actuator in space lasted -- that's how they determined the cause of the spacecraft's going offline.

True, but that confirmed the test run in space, not the other way around. It may have be hard to know in advance if 348 failures on Earth is representative of space, especially because it wouldn’t just be that one system. It would have been lots of parts built in to system working together.

Original mission for Voyager 2 was Jupiter and Saturn fly-bys which was mostly a success. The idea is to engineer parts to survive the mission and maybe go a bit further if you aren't at a point of diminishing returns in regards to cost. If it costs $1000 for a 10% gain in life of part, maybe go for it. $1M for 10%? Maybe not. Additionally, gamma radiation can do some weird things to materials and can effect things differently depending on dose rate. Lubricants can increase in viscosity and acidity under gamma. Radiation effects on spacecraft was not as big of a deal back then. Missions were short and electronics weren't small enough to have noticeable radiation effects.

Re: Voyager 2 is back online after eight months of radio silence

#70

Post by matthewdgreen » Tue, Nov 03, 2020, 3:37 PM UTC

part1of2 wrote: post #51

brazzy wrote: post #5

Earlier quoted context omitted.

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.

> Most academic research is done by underpaid PhD and postdoc students for the love of science I’d hardly call the graduate papers coming out of academia equivalent to the level of innovation & creativity of what the engineers above described. Perhaps they’re both underpaid, but one is certainly more amazing. Hardly the same.

You should read Rhodes’ “The Making of the Atomic Bomb” if you want to understand what incredible engineering feats academic scientists are capable of — when the people are tightly focused on achieving a single goal. You should also read Rhodes’ book if you want to understand why unguided fundamental scientific research itself is so critical, even when it doesn’t immediately seem useful to you: without the discoveries of science, nuclear fission wouldn’t have been understood. (Of course, many will disagree that the development atomic bomb is a good outcome, but that’s a very different conversation.)