Thread by @BrynnTannehill

Let's talk about the Chinese spy balloon that's somewhere over the Northern Continental US now. There's a lot of speculation by folks (see Fox and Friends) who have zero experience with this. So, let your friendly neighborhood defense analyst have a crack at it. 1/n

https://twitter.com/axios/status/1621483090165080065

First, there's a long history of using balloons to get to the US. The general concept isn't new. Japan used highly inacurate "balloon bombs" to try to start fires. One incident killed six people, but it was declared a secret and hushed up. 2/n smithsonianmag.com/history/1945-j…

The Army has been experimenting with high altitude balloons for for comm relay, ISR, and other missions, although it's an open question if the US would do direct overflights during peace time. Much remains classified. 3/n politico.com/news/2022/07/0…

It should be noted that modern balloons, unlike their WWII Japanese counterparts, have some control of their direction. The computers on board can pick the best altitude to get where they want to go, or come as close as possible. This is how they "steer". 4/n

Shooting down balloons with conventional weapons is a tricky business: modern missile systems aren't meant to shoot at them. First, their IR signature is minimal, so you can scratch AIM-9X off the list to start. 5/n

Then there's the altitude. These balloons can hang out at >90k feet. The best US interceptor, the F-22, tops out a little above 60k. Problem is, even if they got there, shooting it down is next to impossible. 6/n

The gap in altitude is sufficiently large that guns aren't an option. Neither is AIM-9X. AIM-120s are radar guided missiles. However, because the balloon has no doppler compared to the the wind and clouds around it, systems tend not to "see" it. 7/n

Modern weapons systems are designed to ignore things that don't move, like chaff, clouds... or balloons as a side effect.

AIM-120 wasn't really designed to engage targets at >90k feet either. The control surfaces don't function as well at such high altitude. 8/n

MIM-104 Patriot missiles can hit things at high altitude, but again, not meant to hit things that have no relative motion to the wind.

Directed energy weapons might work, but we don't have those in service for this mission. 9/n

This isn't the first time China has sent an ISR balloon over US territory according to a US Defense official.

They also claim that the US isn't shooting it down because of concerns about where the wreckage would land. 10/n

abc7news.com/chinese-spy-ba…

It's also worth noting this is the region of the US where some of it's Minuteman III ICBM silos are located. Countries get really twitchy when you start parking military hardware over their nuclear arsenals. This is part of why the Chines ambassador may have gotten a summons 11/n

The fact that it was clearly visible to people on the ground in Billings, and that it appeared to be as big as the moon, suggests that the balloon is either huge, or that it's at an altitude low enough that engagement might be possible. 12/n

Still, this is a low point for US/China relations. When every civilian in Montana can see China spying on the US, culpable deniability by both parties is impossible. It puts the US in the position of having to act very publicly against China to assuage public concerns. 13/n

P.S. Shooting at it, with either guns or missiles, means ordnance, or the exploded bits thereof, will come raining down on people below. Anything that misses the target will continue downrange for many miles. This is dangerous. 14/n theguardian.com/world/2022/nov…

The balloon poses almost no risk to people on the ground. 20mm canon shells and AIM-120 missiles that miss the balloon (or go right through it) pose a non-trivial risk to civilians on the ground. No need to make a bad situation much worse. 15/n