On 21 July, flight controllers in Pasadena, California, uplinked a series of commands that inadvertently caused the Voyager 2 spacecraft to aim itself and its high-gain antenna at a point in space 2 degrees away from Earth. Since then, the probe has been incommunicado, unable to receive commands or beam telemetry and science data to the ground.
While the misalignment is relatively minor, at Voyager 2’s distance from Earth – 19.9 billion kilometres, or 12.4 billion miles – it’s more than enough to keep the spacecraft’s increasingly weak signal, less than a billionth of a billionth of a watt by the time it reaches Earth, from hitting NASA’s Deep Space Network antennas.
Not to worry. NASA says Voyager 2 is programmed to reset its orientation several times a year to keep its antenna precisely aimed. The next reset is expected on 15 October, when flight controllers will be standing by to resume two-way communications. Round-trip travel time for signals to and from Voyager 2: about 37 hours.
Launched in 1977, Voyager 1 departed the solar system after flybys of Jupiter and Saturn. Voyager 2 followed suit after flybys of Jupiter Saturn, Uranus and Neptune. Both have departed the solar system and are now sailing through interstellar space, racing away from the Sun at more than 54,700 kph (34,000 mph).