The list of possibilities is endless. There are signals that are important to national security that you never dreamed of.
When trained for maintenance and repair of the Nike Hercules missile I had to gain a Top Secret NIC NAC clearance due to a portion of the signals relayed to the missile. Had the enemy known the signal they could have rendered the system useless. There are numerous signals for various military systems that must be guarded.
Well, I didn't receive any military training save that necessary to run Uncle Sam's missile warning satellites. But after that, I spent 20+ years "in the black," designing space systems to support various national needs. Let's try to reverse engineer what the Chinese were up to.
First, as myself and others have wondered, and NO ONE SEEMS TO BE ABLE TO ANSWER...why a balloon? Why a balloon of limited life, flying OVERTLY, vs. a satellite that lasts for years and runs over the target area a couple of times a day (or stays continually in view, in GEO)? What can the balloon provide that a satellite can't?
While we're at it, what does the balloon platform give you that rented house crammed with electronic gear, or a van, or a used Cessna 206 can't provide?
Sure, there are signals important to national security that we never dream of. But which ones are of the nature that a ordinary ground or aircraft-based collector can't receive them?
One mission comes to mind, that requires long loitering in a very precise location (both lat and long, AND altitude). But balloons can't do that. They can go up and down, and parlay wind currents to shoot for a given spot. But they won't stay there long, and their ability to control is really kind of poor. But they *could* surf around, passing through these key locations at semi-random. But the time will be short! They can't loiter, with winds blowing 15-50 knots, and that's where the money is.
And, again, you're operating OVERTLY. All we have to do is shut down the appropriate systems if the balloon starts venturing too close to the key points.
Can think of a couple other missions, but they too step rather close to my past life. A balloon would work for those, but there's not much advantage to it.
Finally, let's try to configure the Chinese balloon payload. Ironically, it's going to be very similar to a spacecraft. It has solar arrays, it has "propulsion" tanks (hydrogen or helium to top off the balloon).
Biggest problem is having batteries to let it run all night. It'd need LOTS of batteries. LEO Satellites are in the dark ~45 minutes at a time; this time of year, the Chinese balloon is in the darkness 14 hours day. Even geosynchronous satellites have to handle only 75 minutes or so out of 24 (worst case).
It needs an antenna and a comm system to upload its take to satellites, either Low Earth Orbit ones or regular commsats in geostationary orbit.
To use that, the payload needs an attitude determination system. It needs to know its attitude and orientation to point its comm antenna. Also needs it to point the solar array, but there are lower-cost workarounds for it.
It'll need somewhat of a thermal control system...not much air slipping past. Radiators, probably on the back of the solar arrays like the Space Station.
So...how much is left for the mission payload? Antenna (assuming the mission is ELINT), processor, recorder. With a balloon as the main lifting body, probably not a lot.
Consider the alternative: The balloon's mission is weather data collection, just like the Chinese claim. But they get all furtive about it, and make people THINK something nasty is going on. It's whole purpose is to get certain people riled up.
Ron Wanttaja
Larry Walters - your country is calling you…
