NASA’s Voyager 1 spacecraft has been having increased technical issues since mid-October. The agency’s Deep Space Network has been working on diagnosing and correcting these problems with the 47-year-old craft. Diagnostics became much harder when Voyager’s communications seemed to be cutting out completely.
It turns out that the spacecraft was using a radio transmitter that hadn’t been utilized since 1981.
Voyager 1
On October 16th, the flight team sent Voyager 1 a signal to turn on its heaters, which it should have had ample power to do. By October 19th, it was discovered that the command had triggered the fault protection system, which autonomously responds to onboard issues. For example, if the craft overdraws its power supply, this system would kick in and conserve power by turning off nonessential systems. However, it can take days or weeks before the team can identify the underlying issue that triggered the system.
In this case, the fault protection system caused the crew to no longer receive communication from the vessel. Spacecrafts like this typically communicate with Earth via an X-band radio transmitter, named for the frequency it uses. The Deep Space Network correctly hypothesized that the fault protection system lowered the rate at which the transmitter was sending back data. Since this mode requires less power, it helps the ship converse resources.
This mode also changes the X-band signal that the team needs to listen for. Once they realized what was going on they were able to locate the signal later that same day. During this time Voyager 1 seemed stable and the group began to work on determining whatever had caused the fault protection system to activate in the first place.
Spotty Communication
But these efforts didn’t last long because later that day communication with Voyager 1 seemingly stopped entirely. This left the flight team to once again assume the fault protection system had been triggered. This time they believed it had switched from the standard X-band transmitter to a second radio transmitter called the S-band because it uses even less power.
The thing is, this method of communication hasn’t been used to send messages to Earth since 1981. The other issue is they weren’t even sure S-band could be detected on Earth given the spacecraft’s distance. So, NASA was basically expecting a call on their cell phone but found out it was getting a messenger pigeon.
Fortunately, engineers with the Deep Space Network were able to find Voyager 1’s signal yet again. The team opted not to try to turn X-Band back on again until they could determine what triggered the fault protection system.
On October 22nd, a message was sent to confirm that the S-band transmitter was still working. Allowing for some form of communication with Voyager 1 while they worked on the issue.
Both Voyagers 1 and 2 have been in space for over 47 years, and are the only crafts operating in interstellar space. Their age coupled with their distance from Earth has led to an increase in complex technical issues. Not to mention all the new challenges this creates for the mission engineering team.
