Two incidents in the same time frame, and as it turns out, against two satellites launched within a few months of each other, both from Vandenburg in June and December 1999. Both are earth-observation satellites.

I haven't had time to dig any deeper, but I'm betting that both satellites were based on the same bus, and probably had common components in areas such as communications command and control.

This suggests that somebody (they imply the Chinese) came into possession of very specific information about how to hack specific systems. Maybe even a master encryption key, something that would be deucedly difficult to change aboard the bird after launch. Classic chicken-and-egg security problem, squared.

The specificity is good news, as it limits the scope of the threat very narrowly. It's probably manageable, where a broad conceptual hack would be a first-order nightmare.