The U.S. lost all satellite reconnaissance data on New Year’s eve for a Y2K problem while sharing satellite data with both Russia and China during that period.

A Y2K outage in the Pentagon’s reconnaissance satellites at 7:00 p.m. on December 31, 1999 (midnight 01/01/2000 GMT), causing the loss of all data, including top-secret, spy satellite highest priority data.

The Joint Chiefs of Staff head of Y2K preparedness, Rear Admiral Robert F. Willard, had not mentioned the problem at his 9:30 p.m. news conference. It was later learned that Willard had not been notified of the outage by the Pentagon. The outage was understood to have lasted for three days, with the most sensitive reconnaissance data being redirected to other sites for manual deciphering.

Disturbingly, a mid-1998 Boston Globe article reported that the United States was sharing early-warning satellite data with both Russia and China to prevent uncertainty and panic over the possibility of an unknown attack if Y2K darkened those countries.

Had sophisticated and far-reaching cyber warfare techniques been available in 2000, the outage could have resulted in catastrophic consequences for the United States.