How NASA Fights to Keep Dying Spacecraft Alive

[Krank]

No human-made object has ever traveled farther than Voyager 1, which has made it about 12.5 billion miles from Earth since its launch in 1977. That’s about 137 times the distance from Earth to the Sun, a measure known as an astronomical unit or AU. The probe’s twin, Voyager 2, is at about 112 AU, meaning it too should reach interstellar space sometime in the next few years. Given Voyager 1’s enormous head start and speed – it’s traveling at around 40,000 miles per hour – it’s certainly conceivable that nothing will overtake it as humanity’s most distant outpost in any of our lifetimes...

...In the vacuum of space, there’s nothing to corrode or degrade the spacecraft other than the occasional stray particle, meaning there’s every possibility that these probes will still be out there somewhere millions of years from now. By then, it’s entirely possible that the last humans in existence will be the couple carved onto the Pioneer plaque, those photographed for Voyager’s Golden Record, and Pluto discoverer Clyde Tombaugh, an ounce of whose ashes are aboard New Horizons.



https://www.scientificamerican.com/article/how-nasa-fights-to-keep-dying-spacecraft-alive/

[CitizenBBN]

It will be back, once it finds that machine planet.

As i understand it it's still transmitting isn't it? I know it was when it broke through and basically informed us that there may be more solar system than we thought.

[kingcat]

Love the V YGER reference.

[Krank]

As i understand it it's still transmitting isn't it? I know it was when it broke through and basically informed us that there may be more solar system than we thought.

From the article...

To remain in contact with both Voyager 1 and its twin Voyager 2 nearly 40 years after launch, NASA scientists have had to slowly power down the scientific instruments until, sooner or later, nothing but the transmitter remains. According to Dodd, 2020 is when the shutdown will really begin in earnest in the final effort to squeeze as much time as possible out of the probes’ plutonium batteries.

“We will shut off the heater for a lot of the instruments, and that will save anywhere from two to four watts of power, so six months to a year of power,” she said. That will expose the instruments to the elements of outer space, where it’s only a handful of degrees above absolute zero. “When you shut off the heater, it could mean the instruments stop working because it gets too cold. It could mean that they will continue to work, we really don’t know.”

Here on Earth, Dodd and her team can use NASA’s most modern technology to stay in contact, but the Voyagers are effectively relics of the 1970s.

“The computer systems and whatnot are vintage 1974, 1975, when the spacecraft was being built,” said Dodd. “Your iPhone has 100,000 times more memory than the Voyager spacecraft.”

She compared the challenge of uploading new software to the spacecraft with playing a game of Tetris, with the team having to cram irregular blocks of data into tiny spaces.

[Krank]

Citizen, I would have to dig a little to answer your "limits of the Solar System" question.

As I understand it (or roughly recall it), current estimates of the Solar System's size, which would include ginormous outer fields of weird magnetic bubbles and the heliopause, run to something like three to five light years across... I think, lol. To me, when thinking about our local "feeling" about how relatively close the different planets, and even the Kuiper Belt (Pluto, et al), are to us, our "family", if you will, it's mind-blowing that the entire affected area of space of the entire Solar System stretches half way to the next Star system (Alpha Centauri, et al).

What Voyager I has confirmed, I believe, is some quantification of the edge of the heliopause, but I am unsure if the craft has crossed some actual "last boundary" or not. It is WAY way out there, though, and it is beyond the Oort Cloud and such.

[Krank]

Okay, found this from 2013...

Launched over 35 years ago, Voyagers 1 and 2 are on an epic journey outward from the Sun to reach the boundary between the solar plasma and the much cooler interstellar medium. The boundary, called the heliopause, is expected to be marked by a large increase in plasma density, from about 0.002 cm−3 in the outer heliosphere, to about 0.1 cm−3 in the interstellar medium. On 9 April 2013, the Voyager 1 plasma wave instrument began detecting locally generated electron plasma oscillations at a frequency of about 2.6 kHz. This oscillation frequency corresponds to an electron density of about 0.08 cm−3, very close to the value expected in the interstellar medium. These and other observations provide strong evidence that Voyager 1 has crossed the heliopause into the nearby interstellar plasma.


http://science.sciencemag.org/content/early/2013/09/11/science.1241681


This makes a lot of sense. Basically, a rather large change in temperature, relative to already crazy cold temps, as it is, is strong evidence that a barrier has been passed.

We have a sentry representing "us" out there, beyond our Sun's grasp. That's crazy.

[CitizenBBN]

Yep, that's what I was trying to recall, the heliosphere. I knew that the area now defined as the entire solar system is much farther out than the Kuiper Belt, I thought that was the part it got into.

Cool that our 1970s tech is still out there working. NASA does good work. Their talk about computer memory reminds me of when I first started coding. Working within the memory constraints was a constant part of the challenge. Not so much now.

[dan_bgblue]

strong evidence that Voyager 1 has crossed the heliopause into the nearby interstellar plasma.

There is still a good bit of discussion on that, and some astro scientists contend that event is still to come as Voyager 1 was still detecting "solar wind" particles when that article was published.

[Krank]

There is still a good bit of discussion on that, and some astro scientists contend that event is still to come as Voyager 1 was still detecting "solar wind" particles when that article was published.

Very well could be, dan.

This is one of those things that is, really by definition, extremely difficult to get totally accurate, moment to moment, just from one or two "readings".

I mean, the craft has less power than a flip phone, lol, plus they are having to preserve power most of the time to keep what basic instruments they have running, plus the thing is out there in extreme darkness, extreme cold, etc....

so it sounds like what you have heard or read indicates that it has possibly NOT gotten to the absolute edge of the heliopause (which is what I was originally unsure of), so those folks must contend that the drop in temperature happened, but it was still not enough evidence to strongly indicate being beyond the Sun's relative grasp... even though somebody (NASA?) first came out with this whole "entering interstellar space" thing, like in 2013... I think, lol.