36-year-old ISEE-3 spacecraft flew past Earth

The ISEE-3 route from its launch on August 12, 1978 to August 12, 2014. The

difficult 36-year mission of the ISEE-3 spacecraft is approaching its final completion. Launched in 1978 to study comets and the solar wind, it worked for 21 years, after which it was mothballed in 1999.

This year, a group of space enthusiasts agreed with NASA to bring the device back to life. They conducted a crowdfunding campaign and raised $ 160 thousand. They managed to establish a successful connection with ISEE-3 (using GNU Radio), parse hundreds of pages of paper documentation describing the communication protocol, decrypt the signal, send commands. But, unfortunately, it did not work to start the enginesand adjust the trajectory. However, the path was originally laid so that ISEE-3 returned.

So, on August 9, 2014 the device passed at a minimum distance near the Earth, and on August 10 flew past the Moon at a distance of 15,600 km. Now it will inevitably return to orbit around the Sun.

Communication with ISEE-3 will work for some time. The device transmits readings of scientific instruments and telemetry data.



Collected data transferred to the public domain. Interesting information about how the many-month-long operation to establish communications was posted on the new project site. The idea came to two Skycorp engineers when they had lunch at McDonald's. They realized that it was possible to implement the project if you get the original documentation for ISEE-3. Oddly enough, it was preserved in the NASA archives in piles of yellowed paper from time to time. They were scanned and started to sort.

At the same time, the engineers communicated in forums with other enthusiasts and received help from them. Among the assistants were former NASA employees, operators of amateur radio stations in different countries of the world. By May, we managed to negotiate with the Arecibo Observatory administration to use their 304-meter plate to broadcast the signal. I had to design a transmitter of my own design.

After two weeks of unsuccessful attempts, two-way communication with the device was established, not without the help of NASA engineers.



As already mentioned, it was not possible to start the engines, so ISEE-3 will fly back only in 2029. Perhaps the device will still be in working condition.