What's remarkable is nearly 46 years later both the Voyagers are functional, and a testimony to the reliability & the robustness of the electronics & mechanics of that era. It had only 64kb of memory - about the size of a loaf of bread with the technology available at that time. GE did build the technology, including the command computers and the RTG - Radioisotope Thermoelectric Generators.
Also one should not forget Prof Edward C. Stone, the CalTech Physicist who has served as project scientist for the Voyager program. He received several awards including the NASA Distinguished Service Medal and National Medal of Science.
Prof Stone was the only person to have served as project scientist for Voyager, maintaining his position even while serving as director of NASA's Jet Propulsion Laboratory in Southern California from 1991 to 2001. JPL manages the Voyager mission for NASA. Stone retired from JPL in 2001 but continued to serve as the mission's project scientist.
He retired in October 2022 after serving for 50 years.
"It has been an honor and a joy to serve as the Voyager project scientist for 50 years," Stone said. "The spacecraft have succeeded beyond expectation, and I have cherished the opportunity to work with so many talented and dedicated people on this mission. It has been a remarkable journey, and I'm thankful to everyone around the world who has followed Voyager and joined us on this adventure."
Now back to the topic. How does the Voyager find it's antenna bearings? Quite obviously it can use our Sun to get a fix. But t wasn't enough in terms of accuracy. It needed better alignment because the transmit power of the Voyagers were not that high. Any slight misalignment causes major loss of received power here on the Earth.
The star Canopus was always used for space Navigation. Canopus is the second-brightest star in the night sky, edged out only by Sirius. Also it has an added advantage with its isolation from other bright stars - so it made an ideal choice of getting a secondary fix.
NASA didn't wan't to invest on a new system for the Voyagers and decided to modify & adapt what was used in the previous Pioneer spacecrafts.
This system was designed in the 1970's. The engineers then didn't have the electronics available now. They had access to TTL logic and used Voltage-controlled oscillators, Count-up/count-down logic, Digital integrator (11 bit), Roll error shift register (11 bit)., Precision digital/analog converter (11 bit), Acquisition logic circuits, Count-up bias, High gate latch, Programmable gate circuits, High gate/low gate and cone angle D/A converters to devise a closed loop electro-optical control circuit that could use the sun and other star sensors to align up the antenna towards the Earth.
Also one should not forget Prof Edward C. Stone, the CalTech Physicist who has served as project scientist for the Voyager program. He received several awards including the NASA Distinguished Service Medal and National Medal of Science.
Prof Stone was the only person to have served as project scientist for Voyager, maintaining his position even while serving as director of NASA's Jet Propulsion Laboratory in Southern California from 1991 to 2001. JPL manages the Voyager mission for NASA. Stone retired from JPL in 2001 but continued to serve as the mission's project scientist.
He retired in October 2022 after serving for 50 years.
"It has been an honor and a joy to serve as the Voyager project scientist for 50 years," Stone said. "The spacecraft have succeeded beyond expectation, and I have cherished the opportunity to work with so many talented and dedicated people on this mission. It has been a remarkable journey, and I'm thankful to everyone around the world who has followed Voyager and joined us on this adventure."
Now back to the topic. How does the Voyager find it's antenna bearings? Quite obviously it can use our Sun to get a fix. But t wasn't enough in terms of accuracy. It needed better alignment because the transmit power of the Voyagers were not that high. Any slight misalignment causes major loss of received power here on the Earth.
The star Canopus was always used for space Navigation. Canopus is the second-brightest star in the night sky, edged out only by Sirius. Also it has an added advantage with its isolation from other bright stars - so it made an ideal choice of getting a secondary fix.
NASA didn't wan't to invest on a new system for the Voyagers and decided to modify & adapt what was used in the previous Pioneer spacecrafts.
This system was designed in the 1970's. The engineers then didn't have the electronics available now. They had access to TTL logic and used Voltage-controlled oscillators, Count-up/count-down logic, Digital integrator (11 bit), Roll error shift register (11 bit)., Precision digital/analog converter (11 bit), Acquisition logic circuits, Count-up bias, High gate latch, Programmable gate circuits, High gate/low gate and cone angle D/A converters to devise a closed loop electro-optical control circuit that could use the sun and other star sensors to align up the antenna towards the Earth.
