Communication | Pointing transmitter towards earth

Finding the Earth should be reasonably straightforward, given its proximity to the Sun, which would be bright from the vantage of Alpha Centauri. The on-board star tracker would also be useful, as would locking onto the Starshot laser system.

It may also be feasible to send commands and even reprogram the entire nanocraft via the Earth-based laser system. The angular diameter of a diffraction-limited beam, at a wavelength of 1 micron with a meter-class antenna, is on the order of 0.1 arcseconds. Pointing to this precision could be achieved by using the photon thrusters.

Dec 23, 2017 22:12 Roberto Navacchia Posted on: Breakthrough Initiatives

Good evening the idea of ​​using an umbrella-shaped antenna might be interesting but the idea I've been thinking about would be to create anchors.
those anchors would be like geostationary nanosatellites stopped along the ship's path. logically they must be positioned in advance of the launch of the ship or the various ships, thus creating a road in the literal sense for communication and monitoring the journey. the bigger problem is not the signal of the ship reaching the earth but rather we have a receiver highly capable to receive the weak signal of the ship. the nanosatellites the anchors are like tolls that monitor the passage of vehicles, and are arranged at key points of the pseudo highway. we currently have about 3 ships out of our solar system we can use their data to get to where they are.
best regards Roberto Navacchia
P.S. sorry my bad english

Jan 10, 2018 19:47 Jeff Draper Posted on: Breakthrough Initiatives

I think Roberto's idea is an excellent one when expanded to account for the true power of the entire Starchip idea. Remember that when it comes time for operational launches in the next several decades the Starchip production will be very cheap and automated, likely done in orbit at the rate of several per day. These chip and sail combinations can be designed for very narrow purposes, i.e. some are just cameras and some are guidance systems and some are transmitter relays. You don't have to have everything in one chip. Fire them off in relays and a transmitter chip can take the weak signals from chips ahead of it and boost them back to Earth. Every so often you launch a guidance chip that has nothing but the guidance software and relies on information from other chips to send signals out that correct trajectories. A swarm of single purpose chips will recover much more scientific data then a constant stream of identical operations.

Feb 26, 2018 21:27 Breakthrough Initiatives Posted on: Breakthrough Initiatives

Thank you for your contribution. Daisy-chaining communication is a viable option.

Sep 13, 2018 16:30 Breakthrough Initiatives Posted on: Breakthrough Initiatives


Using a chain of multiple spacecraft to relay data back to Earth is an intuitively appealing concept, and the relatively low cost and potential customizability of each additional spacecraft makes it all the more interesting. The chief difficulty is simply one of area. Even if each spacecraft is able to use its meter-scale sail to collect the signal from the next spacecraft in the chain, it is tough to compete with the kilometer-scale collecting area of the receiving array on Earth. In order for them to be comparable, the spacecrafts would have to be of order a million times closer together than the spacecrafts and Earth (the ratio of a km to a meter, squared), which implies that there would need to be of order a million spacecrafts in the chain. It's conceivable that a sufficiently clever design, a larger lightsail than we are currently imagining, sufficiently cheap spacecrafts, or some other economic aspect of the problem would make the chain a more appealing option in the future.

- John Forbes and Avi Loeb (Harvard), Breakthrough Starshot

Oct 13, 2023 12:44 Posted on: Breakthrough Initiatives


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