The resilience of the signal part... https://www.allaboutcircuits.com/news/voyager-mission-anniversary-celebration-long-distance-communications/ https://www.al

The resilience of the signal part... https://www.allaboutcircuits.com/news/voyager-mission-anniversary-celebration-long-distance-communications/ https://www.allaboutcircuits.com/news/voyager-mission-annive... > The uplink carrier frequency of Voyager 1 is 2114.676697 MHz and 2113.312500 MHz for Voyager 2. The uplink carrier can be modulated with command and/or ranging data. Commands are 16-bps, Manchester-encoded, biphase-modulated onto a 512 HZ square wave subcarrier. The "Manchester encoding" brings us to https://www.allaboutcircuits.com/technical-articles/manchester-encoding-what-is-it-and-why-use-it/ https://www.allaboutcircuits.com/technical-articles/manchest... https://en.wikipedia.org/wiki/Manchester_code https://en.wikipedia.org/wiki/Manchester_code Note that "16 bps" while the system runs at 160 bps. This suggests that the data is repeated ten times and xor'ed with a clock running at 10 HZ. While there's no VOY set up now, https://eyes.nasa.gov/dsn/dsn.html https://eyes.nasa.gov/dsn/dsn.html will occasionally show it. When that happens, you will likely see two set up for it. I've not seen them set up across multiple facilities - the facilities are 120° apart and only one has a spacecraft above the horizon for any given length of time. --- In the "sensitivity to photons" category, I'll also mention https://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiments https://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment... At the Moon's surface, the beam is about 6.5 kilometers (4.0 mi) wide[24][i] and scientists liken the task of aiming the beam to using a rifle to hit a moving dime 3 kilometers (1.9 mi) away. The reflected light is too weak to see with the human eye. Out of a pulse of 3×10^17 photons aimed at the reflector, only about 1–5 are received back on Earth, even under good conditions. They can be identified as originating from the laser because the laser is highly monochromatic. While there's no signal there, we're still looking at very sensitive equipment.