Rockets, Launches, Satellites, ISS, etc.

[John Thomas8]

[RTH10260]

Voyager 1: NASA's longest-running spacecraft back in touch with Earth after five months of silence
The Voyager probes are in interstellar space but Voyager 1 stopped sending back usable information in November. After months of work, NASA scientists have now heard back from the spacecraft.

By Mickey Carroll, science and technology reporter
Tuesday 23 April 2024 11:45, UK

NASA's longest-running spacecraft Voyager 1 is sending information back to Earth again for the first time since November.

Scientists have managed to fix a problem on the probe, which was launched 46 years ago, after five months of silence.

On 14 November last year, Voyager 1 stopped sending usable data back to Earth, even though scientists could tell it was still receiving their commands and working well otherwise.

It was first launched alongside its twin, Voyager 2. The pair are the only spacecraft to ever fly in interstellar space, which is the space between stars.

The Voyager probes send back never-seen-before information about our galaxy. Since they blasted off in 1977, they have revealed details in Saturn's rings, provided the first in-depth images of the rings of Uranus and Neptune and discovered the rings of Jupiter.

Although their cameras are switched off to conserve power and memory, they are still sending back information that would be impossible to get anywhere else.

With all this data stuck onboard and the spacecraft more than 15 billion miles from Earth, NASA scientists needed to fix the problem remotely.

The team at NASA's Jet Propulsion Laboratory in California confirmed in March that the issue was with one of Voyager 1's three onboard computers. That computer, called the flight data subsystem, is responsible for packaging the data up before it is sent back to Earth.

Engineers have confirmed that corrupted memory aboard my twin #Voyager1 has been causing it to send unreadable data to Earth. It may take months, but our team is optimistic they can find a way for the FDS to operate normally again

Within the computer, a single chip containing some of the computer's software code had stopped working. Without that code, the data was unusable.

The engineers couldn't pop over and fix it. Instead, on 18 April, they remotely split the code across different parts of the computer.


https://news.sky.com/story/voyager-1-na ... e-13121317

[John Thomas8]

[keith]

Why don't they use the correct name for this brilliant space craft?

V'GER

[Sam the Centipede]

NASA's JPL has excellent news: NASA’s Voyager 1 Resumes Sending Engineering Updates to Earth

Doesn't it put crappy customer service for washing machines, laptops, etc. into perspective? Voyager 1 is nearasdammit 50 years old - half a century - and it's 24 billion kilometres from Earth, so signals take almost a full day to travel between the spacecraft and Earth, it's not communicating properly, but NASA engineers repaired it.

Just WOW!!!

I don't know whether to be more impressed with the folk who designed and built the Voyagers (which have outlasted their design lives by about 4 decades) or by the folk who now keep these old crates ticking over. Well, it's not a competition, I'm impressed with them all.

For those who designed and built Voyager and are still with us on Earth (I don't think any traveled with the spacecraft!), it must be an immense source of well-merited pride that their creations continue whizzing into the void.

[pipistrelle]

Until it turns into Nomad and obliterates planetary systems.

[chancery]

Voyager 1 Just Announced That It Has Detected 300 Unknown Objects Passing By In Space https://youtu.be/yFYPkfFzYaU

I couldn't listen to more than a couple of minutes of this drek. Does anyone have a text version of the punchline? The only Voyager instruments still working are in the particles and fields category, so I'm skeptical that it has detected anything that could be called "objects" in the ordinary sense.

[johnpcapitalist]

NASA's JPL has excellent news: NASA’s Voyager 1 Resumes Sending Engineering Updates to Earth

Doesn't it put crappy customer service for washing machines, laptops, etc. into perspective? Voyager 1 is nearasdammit 50 years old - half a century - and it's 24 billion kilometres from Earth, so signals take almost a full day to travel between the spacecraft and Earth, it's not communicating properly, but NASA engineers repaired it.

Just WOW!!!

I'm really surprised that they had the ability to update the software on a machine that was probably designed in the early to mid 1970s (it was launched in 1977).

The more recent Mars rovers have that ability, because they're running a commercial off-the-shelf (COTS) real-time operating system, most probably Wind River's VxWorks (they used to brag about this at investor presentations before Intel bought them), and those systems have enough extra memory to be able to stage patch sets before installation so they can recover to a known good state if there's a problem.

[chancery]

The engineers who built and initially operated the Voyager spacecraft were mindful of the need to build as much resilience and redundancy into their systems as possible. They were aware that the mission might continue for decades, even though it was originally only approved for long enough to explore Jupiter and Saturn, about three years.

But the challenges are even more formidable than you might imagine. This article was published in 2015:

Why NASA Needs a Programmer Fluent In 60-Year-Old Languages
To keep the Voyager 1 and 2 crafts going, NASA's new hire has to know FORTRAN and assembly languages.

https://www.popularmechanics.com/space/ ... -engineer/

Larry Zottarelli, the last original Voyager engineer still on the project, is retiring after a long and storied history at JPL. While there are still a few hands around who worked on the original project, now the job of keeping this now-interstellar spacecraft going will fall to someone else. And that someone needs to have some very specific skills.

Yes, it's going to require coding, but it won't be in Ruby on Rails or Python. Not C or C++. Go a little further back, to the assembly languages used in early computing. Know Cobol? Can you breeze through Fortran? Remember your Algol? Those fancy new languages from the late 1950s? Then you might be the person for the job.

"It was state of the art in 1975, but that's basically 40 years old if you want to think of it that way," Suzanne Dodd, program manager for the Voyager program, said in a phone interview. "Although, some people can program an assembly language and understand the intricacy of the spacecraft, most younger people can't or really don't want to."

The last true software overhaul was in 1990, after the 1989 Neptune encounter and at the beginning of the interstellar mission. "The flight software was basically completely re-written in order to have a spacecraft that could be nearly autonomous and continue sending back data to us even if we lost communication with it," Dodd said. "It has a looping routine of activities that it does automatically on board and then we augment that with sequences that we send up every three months."

That's when it's time to turn back to old documents to figure out the logic behind some of the engineering decisions. Dodd says it's easy to find the engineering decisions, but harder to find the reasoning. This means combing through secondary documents and correspondence hoping to find the solution, trying to get in another engineer's head.

The last resort is picking those engineers' brains directly. Many are retired, and are working on 40-year-old memories. Still, the small team working on Voyager today has a list of engineers and others on-hand to call in emergencies. Dodd herself has worked on the spacecraft off and on since 1984, just before the Uranus flyby.

"People's memories 40 years later aren't always accurate," Dodd says. "It's good to have that data point, but you can't guarantee 100% that that was the correct rationale when somebody's trying to recall it."

The New York Times picked up the saga two years later, when Zottarelli finally retired, with an excellent long-form article (gift link).

The Loyal Engineers Steering NASA’s Voyager Probes Across the Universe
As the Voyager mission is winding down, so, too, are the careers
of the aging explorers who expanded our sense of home in the galaxy.

https://www.nytimes.com/2017/08/03/maga ... =url-share

Unlike the astrophysicists who devise experiments for Voyager and who interpret the results, the core flight-team members don’t have the luxury of being able to work simultaneously on other missions. Over decades, the crew members who have remained have forgone promotions, the lure of nearby Silicon Valley and, more recently, retirement, to stay with the spacecraft.

And a wonderful low-key documentary on the team was released in 2022, It's Quieter in the Twilight, which you can stream from Amazon or on PBS.

https://www.imdb.com/title/tt17658964/

You'll find your room gets a little dusty if you watch it.

[northland10]

I'm really surprised that they had the ability to update the software on a machine that was probably designed in the early to mid 1970s (it was launched in 1977).

They're not Microsoft and other tech companies who scheduled EOL to be 2 days after you installed the update.

They also did not annoy Voyager by trying to daily force it to a new version that has more bugs than an Indiana Jones movie (hint.. MS.. I don't want to use Teams 2023 until you fix the damn thing).

[Sam the Centipede]

I think JohnP is saying that building hardware and software that could be updated remotely over a radio signal seems very advanced for the 1970s.

I don't know anything about communications and surveillance satellites but perhaps they were doing similar things back then? It's obviously not ideal if a simple glitch in a bit of code causes an expensive piece of equipment to lose some significant capabilities.

Moving the code away from damaged memory areas working blind from at 22 Tm (22 terametres) is monstrous cool.

And the foresight in building Voyager so it had robust algorithms for what to do if it can't find home, terrific.