How are the Voyager probes still communicating from interstellar space?

The answer

Voyager 1 and Voyager 2, launched in 1977, continue transmitting data from interstellar space - over 24 billion and 20 billion kilometers from Earth respectively. Their 23-watt radio transmitters, weaker than a refrigerator light bulb, send signals that take over 22 hours to reach Earth, where NASA's Deep Space Network's 70-meter antenna dishes detect them. The probes are powered by radioisotope thermoelectric generators using plutonium-238, which produce about 4 watts less each year. By 2025, power levels have dropped to roughly 220 watts, forcing engineers to disable heating and non-essential instruments. In 2023, Voyager 2 briefly lost contact after a wrong antenna-pointing command, but NASA reestablished communication using a powerful 100-kilowatt uplink signal. Scientists expect to maintain some instrument contact until approximately 2030.