The Voyager 2 probe, one of NASA's most widely traveled spacecraft, has been unable to communicate with Earth for the past eight months. Voyager 2 has wandered around the edge of interstellar space on its own, collecting data 11.6 billion miles from Earth and sending it back to us.
But we couldn't answer and call back.
The only radio antenna that can communicate with the probe, Deep Space Station 43 (DSS43) in Australia, has been offline while NASA is making a number of hardware upgrades. Some of the transmitters on DSS43 have not been replaced in over 47 years, according to NASA. To test new hardware, the dish pinged Voyager 2 with some commands on October 29th. It was the first time since mid-March that a signal was sent to the spaceship.
And because the probe is so far away, the communications team had to wait over 34 hours for a response.
Sure enough, Voyager 2 received the commands with no problem and sent a "hello" back.
Fortunately, Voyager 2 doesn't seem to know about it terrible things that have occurred on Earth since March.
NASA's Deep Space Network enables Earth-based scientists to communicate with spacecraft and rovers across the solar system. The network consists of three giant telescopes in the US, Spain and Australia.
However, the US and Spanish telescopes cannot communicate with Voyager 2 due to their trajectory. When the probe passed Triton, a moon of Neptune, it was shot out of the plane of the solar system. If you think of the solar system as a plate, the probe is like a pea rolling around a potato and off the side and moving towards the ground. The northern hemisphere telescopes cannot send a signal from this position - but DSS43 can.
With the cosmic call, engineers and scientists can rest assured that the hardware upgrades have not affected our ability to communicate with space probes.
"This test communication with Voyager 2 definitely shows us that the things we're doing are on the right track," said Brad Arnold, project manager for the Deep Space Network at NASA's Jet Propulsion Lab. The upgrades are expected to be completed by 2021.
Even though the probe is now 43 years old, it just keeps going. A year ago, Voyager 2 Scientists released new data collected by the probe when it entered interstellar space. Earlier this year, before DSS43 went offline, Voyager 2 suffered a glitch that shut down his scientific instruments but it was quickly back online and ready to continue its experiments.
