Not useful, because the signal are too weak to be picked up probe to probe.
On earth, the tiny signal from Voyager at this distance is picked up by dish the size of a football field; same with sending of the signal.
Not useful, because the signal are too weak to be picked up probe to probe.
On earth, the tiny signal from Voyager at this distance is picked up by dish the size of a football field; same with sending of the signal.
Very true insofar as it's a description of Voyager communications. Voyager was 1970s radio engineering. Radio signals spread wide, so you need a big dish to catch it. These days we are using lasers, and laser divergence is several orders of magnitude smaller. And regardless of tech, relay enforces a minimum distance for any signal to spread.
This is a silly counterexample - why would we launch them that far apart? It’s a terrible idea for multiple reasons. We’d want them close together, with some redundancy as well, in case of failures.
What dish size would be required for a “cylindrical/tubular mesh” of probes, say, 1AU apart (ie Earth-Sun distance)? I’m pretty sure that would be manageable, but open to being wrong. (For reference, Voyager 1 is 169AU from Earth, but I have no idea how dish size vs. signal strength works: https://science.nasa.gov/mission/voyager/where-are-voyager-1...)
Light year is 63,241 AU. That means tens of thousands of relays. It would super expensive and super unreliable. The other problem is that achievable speeds are super slow, Voyager is 25,000 years per light year which means that would wait 100,000 years for relays to Alpha Centauri to be possible.
Much easier just to send probe with large antenna or laser, and make a large antenna at Earth.
Starlink has 10k satellites as per this Month. 60k doesnt seem unreasonable?
Starlink has a use case.
At Voyager 1 speeds, it'll take 70,000 years for a probe to reach Proxima Centauri. So you'd just be launching a probe a year for the next 70,000 years to create a temporary chain on a course to fly by one particular star. And for what purpose? Okay, in 70,000 years, if everything works out as expected, we have a chain of probes on a course to fly by Proxima Centauri. What problem does that solve for us ("us" here being whatever is kicking around on Earth after a period of time 5x that of recorded human history thus far).
The dish isn't the size of a football field, it's a 70 meter dish (football field is 110 meters), it can however, transmit at 400 kilowatts of power
Unlike the other comments I actually agree, physics has not changed since the 1970's, even the most focused laser and detector would need to be positioned perfectly to where the next probe would be, and with the nearest star 4 light years away we would be talking a chain of dozens, any of which may fail some way. The probes would also likely be small, cell-phone sized, power restricted, and difficult to shield (you couldn't just throw in the latest wiz-bang 2025 electronics as it all has to be hardened to work multiple decades) Best is a big, transmitter and good receiver one end.
You could send a good amount of small probes and make them become the big antenna dish basically. As long as you cover the bases, you can have layers of "big antenna dishes" in onion layers.
> the tiny signal from Voyager at this distance is picked up by dish the size of a football field
Lots of small fishes can resemble a large fish.
Laser communication could potentially address some of those issues.
Maybe, but if your probe is heading directly towards another solar system then it will be backlit by its destination.
https://space.stackexchange.com/questions/33338/why-is-the-o... is a neat question that addresses this issue.
And yes, the transmitters will need to be powerful enough be a distinct signal over the background of the star that is in the line of sight of the receiver / beyond the transmitter.
My understanding is that's a solved problem - NASA's Deep Space Optical Communication has demonstrated laser communication even with the sun in the background. Laser wavelength and modulation are noticeably different than a stars noise if you filter and just look for the wavelength and modulation of the laser, which is notably shorter and faster than most of the noise coming from the star.
What if the probes carry smaller probes left behind at specific intervals that act as repeaters?
These baby probes could unfold a larger spiderweb antenna the size of a tennis court.
We need quantum entanglement based communication. Maybe without full collapse, using weak measurements, like Alice continuously broadcasts a "retrocausal carrier wave" by sequencing planned future post-selection measurements on her entangled qubits, which backward-propagates through time-symmetric quantum evolution to create detectable perturbations in the present states, biasing Bob's qubits away from pure randomness to encode message patterns.
Both parties perform weak measurements on their qubits to extract these subtle signals without collapsing the entanglement, preserving high coherence across the stream. A quantum Maxwell's demon (e.g. many experiments but can be done: https://pubmed.ncbi.nlm.nih.gov/30185956/) then adaptively selects the strongest perturbations from the wave, filters out noise, and feeds them into error correction to reliably decode and amplify the full message.
I put something together: https://github.com/DOSAYGO-STUDIO/quacomms?tab=readme-ov-fil...
> which backward-propagates through time-symmetric quantum evolution to create detectable perturbations in the present states,
That's not how quantum physics works. You might be misunderstanding delayed-choice. If you do think it works this way, I encourage you to show a mathematical model: that'll make it easier to point out the flaw in your reasoning.
You cannot exchange information with quantum entanglement. It’s impossible.
The problem is each relay needs its own power source so it's not going to be as light and small as you would like. Solar power doesn't work very well outside of the solar system, or even really in the outer solar system.
On the plus side your big probe could push off of the small probe to give itself a further boost, also necessary because otherwise the small probes need thrusters to slow themselves to a stop.
Sure, drop one repeater every light-day. 1500 of them. Each one will need fuel to decelerate enough to remain in place.
You can't leave anything behind. That would need to be accelerated to 50,000 km/h or have even bigger rockets than launched Voyager in the first place.
Football field might even be too small…
Wasn’t Arecibo used for Voyager?
It might have from time to time... but it had limited ability to track.
As I type this, DNS Now is currently receiving data from Voyager 1. https://eyes.nasa.gov/apps/dsn-now/dsn.html
https://imgur.com/a/kXbhRsj for a screen shot of the relevant data.
The antenna data is https://www.mdscc.nasa.gov/index.php/en/dss-63-2/
No. Or not any more, DSS-43 at the Canberra Deep Dish Communication Complex is the only antenna that can communicate with the Voyagers.