Plasma Wave Subsystem (PWS)

technology

A pair of long antennas and a receiver that listen for electric-field oscillations in the surrounding plasma. Its importance to this mission is a consequence of a failure: Voyager 1's plasma science instrument stopped working in 1980, so when the spacecraft crossed into interstellar space in 2012 there was no direct density measurement available. The plasma wave instrument supplied one indirectly. A disturbance from the Sun sets the local electrons ringing at their plasma frequency, and that frequency depends only on the electron density, so measuring a tone near 2.6 kilohertz gives a density of about 0.08 electrons per cubic centimetre. That number, far above what solar wind at 121 AU would give, is the measurement on which the claim of interstellar arrival rests. The instrument is still operating on both spacecraft in 2026. Not a place.

A technology is not a place. Drawing it on a map would assert something about the world that no stored fact supports.