9X has a cooled focal plane IR sensor, from which it derives video. IOW the sensor is an IR video camera on gimbals.
In the video you see the limited burn time of this relatively short range missile, and hear the sonic boom it generates immediately after launch.
I believe the warhead did not detonate, or perhaps the missile was purposely configured with a mass simulator in place of the warhead, to make the bring down as safe as possible. If the missile went through the balloon itself there may not have been a contact destruct generated in any case.
“and hear the sonic boom it generates immediately after launch.”
Stick to your day job.