NASA sends first commands to Voyager 2 in eight months
NASA is back in contact with Voyager 2 after almost eight months of silence. Radio communication has not been possible because the Deep Space Station 43 (DSS43) in Australia is undergoing an upgrade, but on October 29 it sent a signal to Voyager 2, which successfully carried out the commands and returned a confirmation signal.
The 43-year-old Voyager 2 is currently over 11.6 billion miles (18.8 billion km) away from Earth as it hurtles toward interstellar space, never to return. Thanks to its nuclear power source, it will remain functional for several more years and is sending back data about the outside of the heliosphere on the edge of the solar system.
Unfortunately, the conversation has been entirely one sided since March because DSS43, the only radio antenna capable of sending a powerful enough signal at the right frequency has been down for a major upgrade. This upgrade includes installing two new transmitters and improved heating and cooling equipment, power supply equipment, and additional electronics.
The 70-m (230-ft) DSS43 is part of NASA's Deep Space Network (DSN), which is a collection of three ground stations located in Goldstone, California; Madrid, Spain; and Canberra, Australia. These allow the space agency to remain in contact with deep-space missions around the clock. However, the stations in Spain and the United States can't communicate with Voyager 2. Only DSS43 can.
The reason is that when Voyager 2 flew by Neptune's largest moon Triton in 1989, the maneuver sent the craft over the planet's north pole and then on a trajectory that went south of the plane of the ecliptic. This means that Voyager 2 is only visible in the southern sky and is never visible to Goldstone or Madrid. That leaves only DSS43 in the Southern Hemisphere. The DSS43 upgrades have already left a gap in the DSN for sending commands, but for Voyager 2 it meant a complete loss.
DSS43 is scheduled to return to full service in February 2021.
"The DSS43 antenna is a highly specialized system; there are only two other similar antennas in the world, so having the antenna down for one year is not an ideal situation for Voyager or for many other NASA missions," says Philip Baldwin, operations manager for NASA's Space Communications and Navigation (SCaN) Program. "The agency made the decision to conduct these upgrades to ensure that the antenna can continue to be used for current and future missions. For an antenna that is almost 50 years old, it's better to be proactive than reactive with critical maintenance."