“Voyager 2, that's the call of the earth. Are you reading?"
Last week the answer was finally "yes". And luckily, after eight months of no communication, Voyager2 appears to be fine.
On October 29th, NASA's Deep Space Network communicated with the spacecraft Voyager 2 for the first time since March of this year. The only radio antenna powerful enough to send and receive the weak signals from the 43-year-old spacecraft is the 70 meter wide Deep Space Station 43 shell in Canberra, Australia. But the gigantic radio bowl was offline for repairs and upgrades.
The communication last week was part of a test of the new hardware, but the upgrades are still ongoing.
"Work on DSS43 has not yet been completed," said Richard Stephenson on Twitter. Stephenson works in Operations at the Canberra Deep Space Communication Complex. “Shortly after a good command link with Voyager 2 was confirmed, the engineering team started working on further structural improvements. The antenna has yet to be optimized for X-band, which requires clear skies and a few weeks of work. "
NASA expects the work to be completed in February 2021. It currently takes about 17 hours and 25 minutes for a signal to reach Voyager 2, and then the same time for the spaceship to send a signal back to Earth (For the latest data on the two Voyager spaceships, see here.)
An artist concept depicting one of NASA's two Voyager spaceships, the most distant and longest-living spacecraft known to man. Photo credit: NASA / JPL-Caltech
During the repairs, Voyager 2 was "flying solo" based on the last commands it received before the Canberra Court went offline. Voyager 2 returned a signal confirming that it had received the "call" and carried out the commands with no problem.
The upgrades to DSS43 include two new radio transmitters. One of them spoken to by Voyager 2 hasn't been replaced in over 47 years. The engineers also upgraded heating and cooling equipment, power supplies, and other electronics required to operate the new transmitters.
Every now and then there is a perspective shot that triggers a "Wow! That's big" comment. Seeing the man walking across the surface of the bowl towards the hoist is one of those shots. pic.twitter.com/DeKcOGwigH
– Richard Stephenson (@ nascom1) November 2, 2020
"What makes this job unique is that we work at every level of the antenna, from the pedestal near the ground to the feedcones in the center of the dish that extend over the edge," said Brad Arnold. the DSN project manager at NASA's Jet Propulsion Lab. "This test communication with Voyager 2 definitely shows us that the things we are doing are on the right track."
The Deep Space Network consists of radio antenna systems that are evenly distributed around the world. You are in Canberra; Goldstone, California; and Madrid, Spain. The positioning of the three facilities ensures that almost any spaceship with a line of sight to Earth can communicate with at least one of the facilities at any time.
However, the Canberra court is the only one that can communicate with Voyager 2. To see Neptune's moon Triton up close in 1989, the probe flew over the planet's north pole. This trajectory deflected it south relative to the plane of the planets and has been moving in that direction ever since. The spaceship is now more than 18.8 billion kilometers from Earth and so far south that it has no line of sight with radio antennas in the northern hemisphere.
The upgrades to DSS43 will also be beneficial for other space missions, particularly the landing of the Perseverance rover on Mars on February 18, 2021.
Voyager 2 captured this image of Neptune in 1982 when it was more than 7 million km from the planet. The Great Dark Spot in the center of the picture was the first storm ever seen on Neptune. Photo credit: NASA / JPL.