Patching Voyager from 12 Billion Miles

NASA patching nearly-50-year-old code on Voyager 1 and 2 — at distances where instructions take 18 light-hours to arrive.

Voyager spacecraft. Image: NASA/JPL.

Patching code written almost 50 years ago at a distance of 12 billion miles (over 18 light-hours):

“Voyager 1 and Voyager 2 have traveled more than 15 billion and 12 billion miles from Earth, respectively. At those distances, the patch instructions will take over 18 hours to travel to the spacecraft. Because of the spacecraft’s age and the communication lag time, there’s some risk the patch could overwrite essential code or have other unintended effects on the spacecraft. To reduce those risks, the team has spent months writing, reviewing, and checking the code. As an added safety precaution, Voyager 2 will receive the patch first and serve as a testbed for its twin. Voyager 1 is farther from Earth than any other spacecraft, making its data more valuable.”

https://www.jpl.nasa.gov/news/nasas-voyager-team-focuses-on-software-patch-thrusters

Originally posted on LinkedIn.