...its pretty clear that the "rumors" I mentioned
are certainly not classified any longer, and I won't be betraying my security oath if I tell you about how I learned about this.

I had worked with SAR data before, when I was at my oil company job, but one of the earliest satellites launched with synthetic aperture radar capability suddenly went silent. The official line was that it had just failed unexplainedly due to some internal malfunction.

Years later, when I was working for a defense contractor, the rumor went around that it had been shut off deliberately when they found the wakes of submerged submarines could be clearly seen in images of open ocean waters. This was a NASA earth resources mission, with no military or intelligence potential and the protocol was for open distribution, so they simply had to pull the plug on it before the Soviets started using our own freely available data to track our boomers.

We wouldn't have had security access to any of this, but the spook community is a small, and alas, a gossipy one, so soon we were speculating about just what had happened to the bird.