Yay! Woot woot!
Celebrating like Disco Stu!
A signal from Voyager 2 has been detected by NASA's Deep Space Network (DSN) over a week after communications with the distant probe were lost, the US agency's Jet Propulsion Laboratory (JPL) on Tuesday. The disco-era spacecraft was detected by Canberra Deep Space Communication Complex's 70-metre dish, Deep Space Station 43 ( …
The Dara O’Briain programme about the moon was good BUT it was wrecked by the constant breaks for adverts every 10 minutes. Without the adverts the whole thing could have been condensed down to about 20 minutes. Best watch it on catch-up if you have the ability to skip the ads!
> Interesting that this news is released the same day as Dara O’Briain Wonders of the Moon airs on television. Coincidence……..?
I only ended up with half an ear on the show when it explained what a supermoon was -occasionally reported right here- but the BBC explains the current batch of lunar phenomena here (namely Sturgeon Moon, (rare) Blue Moon, (rarer) Harvest Moon respectively)
// Mr O'B? -->
This gives a bit of insight regarding the question "what happens on the reset".
From New Scientist.
But if anything were to go wrong, we would have no way to send any commands to Voyager 2 while the antenna is pointed away from Earth. “We are now generating a new command to attempt to point the spacecraft antenna toward Earth,” said Dodd. “There is a low probability that this will work.”
Even if it doesn’t work, all is not lost – Voyager 2 is programmed to automatically reset its orientation a few times a year in case of situations just like this one.
I'm curious as to whether at that distance Sol is still the brightest star in the neighbourhood (my guess would be yes) - and if Earth is close enough that the angular distance between Earth and Sun matters (also yes). That would ease the task of working out where to point the dish, I suppose.
...my guess would be yes... -- Your guess would be correct!
Calculate apparent magnitude: m = (M-5) + (log10(d*5))
m = apparent magnitude
d = distance in parsecs
M = abs magnitude
(M) Abs Mag Sol = 4.75
(d) V2 distance = 134 AU = 0.0006496456 pc
m = (4.75 - 5) + (log10(0.0006496456 * 5))
m = -0.25 + -2.48835349431
m = -2.23835349431
Taking Sirius app mag from Earth (cos too lazy to calc the difference, and it'll be insignificant!):
Sirius m = −1.46
Sol m at V2 = -2.24
So yup, Sol still brighter.
 As the brightest star in the night sky.
PS. Heeeelp! I need a life!
PPS. I'll calculate the distance V2 needs to be for that not to be the case, after some therapy -->
PPPS: No, really: Heeeelp!!!
Also on ElReg: https://www.theregister.com/2023/07/31/nasa_mistakenly_disconnects_voyager_2/
"NASA reckons the situation is temporary and will not end the probe's nearly 46-year stint in space as it is programmed to recalibrate its position a few times a year. October 15 is the next scheduled reset."
If I've done my Maths right* I calculate that all we need to do is put a massive radio telescope 0.7 light hours (~750 billion kilometers) from Earth, where Voyager 2 is actually pointing and we're back in business. I'm sure there's an egotistical billionaire or three that would be willing to try.
[*It's been a while since I put any real trust in my prowess with trigonometry, so your mileage (or km-age) may vary.]
You can check against our workings from the article "We've lost our probe!" last Monday;
Draco's calcs: https://forums.theregister.com/post/4704486
Yours Truly: https://forums.theregister.com/post/4705186
[I made it 1.125B km - but looking back I'm not sure my inputs were correct!]
Though primarily focusing on Voyager 1 - Tom Scott visited the JPL a few years back - https://www.youtube.com/watch?v=YLlzx6v8CcA - and the intro to that video still freaks my mind.
"The Voyager 1 space probe is the furthest man-made object from Earth, and the fastest. But right now, it is moving towards us. Relatively speaking."
Note what is said about the strength of Voyager 2's signal strength in those videos. It is strong - several dB above the noise, and stronger than other probes which you would expect to be stronger. Voyager 2 will run out of power for its communications before it is too far away to contact. Uh... as long as the spacecraft has its antenna pointed Earthward.
And that's our closest neighbouring star.
Technically, Proxima Centauri is the closest star (Alpha Centauri is a 3-star system and Proxima Centauri is Alpha Centauri C). If you are talking about Alpha Centauri as a star, and not the system, then it would refer to either Alpha Centauri A or to A and B together (as they appear as one star in the night sky due to their proximity).
At some point, Proxima Centauri will be further away, as it orbits the A-B system, but this won't happen for another 25,000 years or so, at which point A and B will alternate being the closest star (every 79 years) until Proxima comes back round again.
At its current speed V2 travelling from Alpha Centauri AB to Proxima would take in the region of 4000 years! (Depending on the flexibility of rounding!)
From the esteemed Wiki: Currently, the distance between Proxima Centauri and Alpha Centauri AB is about 13,000 AU (0.21 ly), equivalent to about 430 times the radius of Neptune's orbit.
 That's about the age of the Earth *cough* according to some *cough cough*
" That's about the age of the Earth *cough* according to some *cough cough*"
It is about two thirds of the age of the Earth, the planets and the stars, as well as everything else according to the Abrahamic myths.
Some other creation stories *do* have her being younger and some far older.
By a strange coincidence, Science has the current age of the Earth and the half-life of a uranium isotope being of roughly the same magnitude.
"Weird to think it'll be another 300 years before it gets to the Oort cloud."
And millennia before she passes out of it. The cometary zone is *huge*. It extends half-way to Proxima ...
Which leads to interesting ideas.
Should Proxima and all her little freinds, such as Wolf 359, have extended cometary zones it may be possible for City-Farms to use the ambient resources
to sustain themselves while drifting from one to another. Interstellar travel, the slowest way. Indeed, a loosely coherent "civilisation" of City-Farms may be
the easiest way to colonise the Galaxies.
Not that it will ever happen but it's nice to think about.
"Space is mind numbingly big." Citation needed?
"just faithfully doing its duty"
Hmmm... Where have I heard that story before?
A lonely space craft, roaming through space, sending signals dutifully, but getting no reply from its creators who killed themself by war and pollution...
OP: "...hoping that someone talks to him?" You sure it's a boy? ;)
Talks to *her*.
Machines are generally considered to be feminine in English, ships more so and all of those little robots are ships. Spaceships.
Planets, stars, countries and a few other classes of objects are also female. Why this is is too deeply buried in the Anglo-Saxon-Teutonic past to be
It may seem strange, but even Sol and Jupiter are female. :)
Why do I now have a vision of a giant mirror ball hanging off the back of Voyager, and NASA shining some flashing lights into the night sky looking for a reflection to pinpoint it's position.....
Maybe it also has a medallion and hairy chest wig, too ?
But, top marks to the boffins, as usual, and tip of the hat to whoever thought of putting in a self-alignment cron job, all those years ago.
Data slowly starts arriving again.
October 17th: Jackie, the junior researcher, who nobody ever listens to, notices anomalies from the magnetometer.
October 28th: Europa occluded. Jackie knocks excitedly on door to gamma ray observatory
November 20th: Xeelee Nightfighter, wings furled, settles into Lunar orbit. Pilot apologises for bumping into Voyager, supplies NASA with insurance details
November 22nd: first attempts to sue Xeelee pilot for whiplash arrive at JPL.
December 9th: Xeelee insurance company responds to the claims.
Date unknown: remnants of humanity stare up at gaps in the dark, dark clouds, thinning at last, as the first stars are seen to shine through once more.
Brings back childhood memories of my first cassette tape recorder (Sanyo) and the above album which was given to me, or maybe it was that woman with the leg I remembered the most...
$DEITY, did you have to remind me?
If 1970s technology can reliably and consistently sort itself out and talk to Earth after nigh-on 50 years, think what a craft with today's tech could achieve. Even using radiation-hardened 'old' but relatively proven hardware based on, say, 20 year old technology would be a massive leap over what VGER can do.
I'm thinking even higher resolution photos of Saturn's moons, Pluto etc.
Don't think there's been a post and I cant find out how Voyager actually reorients itself.
I can't imagine mechanical gyros would still be running after all this time (I could be wrong), random searching for a home signal would be too vague, a star finder (and plate solving) would work but not with 1970's level hardware .... So how does it know where its relevant bits are pointing, where it's going in space and whether it's going to get there ...?
Sun and Earth Pointing: The spacecraft are designed to keep their high-gain antennas pointed toward Earth, and their solar panels. oriented toward the Sun. This ensures that they can maintain communication with Earth and continue to receive power from the Sun for their systems. They don't comb for a signal as that would consume propellant which over the life of the mission is now very low. Just pointing at the sun and knowing the time from the ultrastable clock allows a compute of the change of antenna orientation from sun to earths orbital position. The futher away the spacecraft from earth the smaller the angle of change requred to adjust for Earth orbital position round the sun. By now it's probably very small.
Voyager has a system called Attitude and Articulation Control Subsystem (AACS) which is responsible for maintaining orientation etc. It has various systems in it, including a "Sun Sensor" and "Star Tracker" both used for attitude reference. There's an article here on how it was designed to be autonomously fault tolerant given that communicating with earth was critical for mission success. https://arc.aiaa.org/doi/epdf/10.2514/6.1981-1812 (requires sign in after abstract)
This article has some more details as well... https://hackaday.com/2023/07/31/just-how-is-voyager-2-going-to-sort-out-its-dish-then/
Effectively the star tracker keeps its eye on the Star "Canopus"- which is conjunction with the direction of the Sun, allows it to orient itself.
I've followed the voyager missions since their launch in 1977 and being a space nerd I would have been sad if the end of this voyager was caused by human error. What is gobsmacking is the sensitivity of the ground station to be able to detect the carrier with the voyager dish 2 degrees off beam, wow!
Call me nostalgic or whatever but I've seen stuff going on long before most of you readers were even born! I don't remember the unix timestamp of 0 as I was still watching 405 lines TV of Apollo back then.
Great news, but I'm a bit confused. They lost contact with Voyager when the antenna was moved 2 degrees off beam, but they can still send a signal to re-align the antenna? Two degrees is quite a big error over such a distance. So they haven't lost contact? Or was it just a very weak signal due to the 2 degree misalignment and they managed to bash a signal into it by using high power? And another question - if Canberra can contact it, why can't the slightly bigger Jodrell Bank? Or maybe the angles are wrong at the moment? Sorry about all the question marks but I have a vast stock of them that I really must get through.
2 degrees off as a straight line, like say a laser, is an enormous error, but for a radio signal there will be a certain amount of beam spread. At that distance, even a spread of microns per mile would likely be enough to hit Earth's entire orbit (no I did not try the math.) There are also sidelobes off the main signal for a parabolic antenna that allow for a surprisingly strong signal when the aim is a couple of degrees off. As I recall from my satcom days, a sidelobe is about 10dB lower than the main signal, and occasionally caused acquisition problems when the ground station operator was incapable of understanding that no, he is not locked on, keep tracking over. Anyway, a sidelobe would be detectable from an off-center antenna and may even work well enough to command the satellite to realign early. It's far from optimal and not guaranteed to work, but then it may when you consider the baud rate of 1970s communications when 4.8KBPS was incredibly fast.