The thought that the sites might be shielded horizontally but not vertically is intriguing. However, it does seem a bit of a stretch that the people involved with approving nuclear sites would approve such an approach. "Why are the pigeons on the roof glowing?"
I wouldn't say not shielded, but perhaps less shielding on top.
Consider a missile silo.
You can't detect much radiation from the lateral directions but you might from overhead. Personnel are located to the sides of the launch silo and must be protected. A vehicle driving on a road many miles away might not be able to tell very much.
BUT - Might it be possible that taking overhead radiation measurements for several years could give you a database such that you could estimate when a site had warheads installed in its missiles, or how roughly how many nukes were ready to go? Might you be able to learn when a site is or isn't a threat?
Montana is one of the states that has these missile silos.
But fixed sites like we're talking about don't spring up overnight. Satellite imagery will note the facilities being built, and unusual features such as heavy shielding. Classic intelligence work would uncover the contractors, and gain insight into the design of the facility. The balloon would only be useful if we WERE running some sort of "shell game".
Sure, the facility is a fixed location and well known. But is it ready to launch an attack? Not all missiles are ready to go all the time. Missiles and facilities are frequently undergoing maintenance and upgrades and warheads are often removed, serviced, replaced, etc. Would it be useful for an enemy to know which sites are ready to shoot and which are not, or at least which are at reduced capacity? You bet.
Of course, this is just speculation about why a balloon might be useful when flown over Montana. There could be other reasons.
Last edited: