The Prodigal Son Returns, But...

The Prodigal Son returns, but we no longer speak its language...  The story came from the always interesting blog of Emily Lackdawalla a few days ago.  The spacecraft known as the International Sun/Earth Explorer 3 (ISEE-3), launched in 1978 and repurposed in 1983 to study a pair of comets, then named the International Cometary Explorer (ICE), is returning to Earth's vicinity.  She reports that though a dozen of 13 instruments continue to operate, and it still has maneuvering fuel, at NASA's investigation into a possible repurposing of it, Goddard Spacecraft Center indicates we can no longer communicate with it.  Obviously the standards for radio signals has changed in those decades and the hardware needed to upload information to the spacecraft was retired and surplused in 1999.  The cost to rebuild new hardware to speak in an obsolete standard was determined to be too high to consider. 

So while it listens for instructions as it approaches the Earth, we won't be able to talk to it.  Interestingly, if it is ever recovered, NASA has already donated it to the Air and Space Museum, but that would require extraordinary effort as well.  As a long-term fan of spaceflight, it is sad to see it happen, but I'm amazed it hasn't happened before.  How many of you can download software for your computer from 3.5" floppies which was the standard just 15 years ago?