Welcome home

On August 12, 1978 NASA launched a small spacecraft called ISEE-3 to study the interaction between the earth's magnetic field and the "solar wind" emanating from the sun.

In 1997, NASA abandoned ISEE-3 due to a data link rate which had deteriorated to the point of unusability.  There has been no regular contact since, although the spacecraft remains in an orbit around the sun which occasionally brings it back near earth.  A brief carrier signal was established in 1999.

In 2008, a deep space comms network reestablished a data link with ISEE-3.  To the surprise of all, the spacecraft is still almost fully functional, and even has some propellant remaining.  The problem: the equipment involved in communicating with the spacecraft is now ancient history, and no longer exists.  NASA announced that rebuilding it was not worth the cost and that the spacecraft would be abandoned.

Enter the internet.

The original specs on the spacecraft were long since in the public domain, so a group of scientists, engineers and programmers decided to explore the option of open-sourcing control of the craft.  The ISEE-3 Reboot Project was born.

The team managed to obtain and construct the necessary communications gear (think Space Cowboys here) and somehow talked The Man into letting them install it on the Arecibo antenna.  It's basically a remodulator and power amplifier with the rest of the hardware done totally in software as wire-wrap hadn't been invented at the stage that ISEE-3 flew.

On May 29, 2014, the team successfully established a datalink with ISEE-3 and have managed to command the spacecraft into engineering mode to begin transmitting telemetry and allow debugging.  The next step is to fire an orbital adjustment burn which will place the spacecraft in an extended earth halo orbit.  if this doesn't happen by mid-June 2014, the next time we see ISEE-3 will be sometime in 2040.

Hopefully, welcome home, little fella.