Antique Voyager Technology

sea_stuart writes with a story from the Tidbinbilla space tracking station, outside Canberra, Australia. It is still communicating with the two Voyager spacecraft 30 years after they were launched and 18 years after Voyager 2 passed close by Neptune. Here's a little background on Voyager 1 and Voyager 2. "The bank of computers that would look at home in black-and-white episodes of Doctor Who cannot be junked... [T]he 1970s hardware is now our world's only means of chatting with two robot pioneers exploring the solar system's outer limits. Today Voyager 1 is humanity's most remote object, 15.5 billion kilometers from the sun. Voyager 2 is 12.5 billion kilometers from it. Both continue beaming home reports, but now they are space-age antiques. 'The Voyager technology is so outmoded,' said Tidbinbilla's spokesman, Glen Nagle, 'we have had to maintain heritage equipment to talk to them.'"

Comments

I worked on this project

[rimcrazy]

What is little known externally except by those that actually worked on this project is that the radios work at all is amazing. Motorola GEG built the radios in the Voyager spacecraft. Right after launch of both space crafts there was a failure of a critical capacitor that sets the bandwidth of the acquisition loop filter. The net result of that failure was that the signal acquisition of the radios was severely impaired. In order to compensate for this NASA engineers developed an emperical model of the entire spacecraft while it was on it's initial loop around the sun for it's slingshot to Jupiter. Since it was relatively close they could hit the spacecraft with a very large signal thus ensuring acquisition of the transmitted commands. The model consisted of predicting exactly where the front end input LO would be depending upon the temperature of the space craft, the added doppler due to movement, aging of the crystals, etc, etc. Basically anything that could effect the LO was factored in. Once the model was complete, the ground stations would then use and probably still use, this model to predict what the frequency for lockup needs to be. Due to the efforts of the engineers at NASA, they were able to "save" both spacecraft and the mission. And they still work today!!! Pretty amazing.