Low altitude platforms like this excel when it comes to forms of ELINT and SIGINT. Interestingly, SIGINT these days refers to more pedestrian forms of radio communications and in certain cases radars. ELINT in many cases cannot be collected via satellite since ionized regions of the atmosphere occlude signals before they could even reach sensors.

Information on this incident is obviously heavily manipulated, but what I found interesting was once the US divulged a U2 was orbiting the object for some time (primarily because it was one of our only known platforms that could loiter at such a high altitude) TheDrive reported that as we were attempting to collect ELINT from the balloon the transmitters on the balloon were too powerful to jam [0].

I'm not a fan of politics here on HN, but I still maintain this as one of the biggest blows geopolitically to our national security in decades.

0 - https://www.thedrive.com/the-war-zone/u-2-spy-planes-snooped...