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Comment by pengaru | Hacker News Reader

Impressive that NORAD can detect, and an F-22 can then hit such a small target with no substantial heat signature using a missile.

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No, not impressive. The club is a radio hobby club and the balloon is a radio beacon balloon, which transmits its location and height unencrypted on an open frequency, as do basically all balloons. Except for those from china, apparently.

If they really shot down that balloon, and not a Chinese one, they used a 500,000 rocket started by a 200mm plane to kill a $100 balloon. Spending so much on so little on the other hand is impressive.

> which transmits its location and height unencrypted on an open frequency

Usually once every hour or every other hour for a quick second long burst, otherwise they are powered down and just floating. Pico balloons can't carry more than a few grams and depend on solar panels to charge up a battery enough to transmit.

Also air to air missiles are not magic. They don't have secret decoders for every imaginable protocol to lock on to targets (and assume they aren't lying about their location). They are either slaved from the planes radar, contain their own radar, or use heat signatures to lock on.

Your overall point stands, but I can see where the original poster seems to be coming from. There are "anti-radiation missiles", which lock into transmitters to blow them up.

IE: The AGM 88 "HARM" missile does this. But these are not used by air-superiority fighters like F22, but instead by "Wild Weasel" fighter jets against ground RADAR targets.

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I think the poster you responded to magically assumed that a AGM-88 would work against a balloon. But that is mistaken: the balloon isn't transmitting enough of a RADAR signature for something like HARM to lock into it.

As a taxpayer, I think the AF using a $100 (or was it $12) balloon for target practice is way better than say the $570K BQM-167 remote drone that they'd normally use!

https://dronedj.com/2021/03/24/the-air-forces-training-drone...

Those cost differences are striking. An adversary could launch thousands very cheaply. I wonder how militaries would react to so many potential targets.

In the worst case, you would react by directly attacking the adversary that launched them. Hopefully by the time things had reached that level you would have had an opportunity to exhaust all diplomatic channels and could have found a more peaceful resolution.

With technical escalation.

https://en.m.wikipedia.org/wiki/Barrage_balloon

Investment would lean back towards gun based AA, like anti-air artillery since the objects are so high. Investments are already going back into that direction as cheap drones like the SHAHED are easily managed affordably by systems like Gepard. It's actually quite fun to see these systems revived.

I think laser-based weapons would be more likely, honestly. It should be possible to heat up a balloon enough to melt the envelope without an absurd power supply.

Perhaps not so well when everyone's a Captain Kirk.

They said thousands, not 99.

And they usually have radar reflectors on them also.

Such as - https://www.overlookhorizon.com/wp-content/uploads/2018/09/5...

Missiles are not designed to lock onto voluntary transponders, for hopefully obvious reasons, meaning the AIM-9x in this instance has demonstrated either a very sensitive IR sensor, or a very sensitive radar setup.

Sure there's a radio signal, but Sidewinders are heat seekers. While I can believe one went for the electronics package on the Chinese balloon these pico balloons shouldn't have anything more than a bit of solar heating.

Detecting them is probably easy--note the balloon material appears shiny. Probably aluminized mylar, it will show up on radar.

Of course the rockets are heat seeking. But someone has to give the order. They have sensors, they investigate. They report up the chain of command. I don't even want to know how many people were involved from the moment it was detected to the moment the order was given. 100? 1000? More? And no one bothered. And the US weather service alone starts around 60,000 to 100,000 balloons a year.

It doesn't matter how you FIND an object if you can't target it. That's why articles crying that china can track the F22 and F35 are meaningless, because knowing something is in your sky and being able to direct a munition into it are very different things. Pilots who have practiced dogfighting the F35 have expressed surprise at just how close you can be and still be unable to get a good enough radar return from the targeting beam to actually shoot at it.

Can you explain why the chain of command has anything to do with whether or not it should be considered an impressive technical feet for a thermal-imaging missile to lock onto a balloon?

I didn't say it was a good use of resources.

When you think about it, not really. The F22 went into service 15 years ago and has a radar cross section about the size of a honey bee. I would hope that our air defenses would be designed to detect aircraft like that, and I would also imagine a balloon with no thought to stealth would show up really nicely on any radar that didn't filter it out.

As for the heat signature, and I admit I'm doing more guesswork here, it works via IR contrast. As long as the balloon was sufficiently warmer than the air around it, and you were close enough, it should track just fine.

For NORAD and other air defense platforms, they're a ton of filtering that must be done to ignore cruft, otherwise they'd be responding to floating plastic bags, birds, etc, constantly.

From the missile system and fighter radar perspective, that's not something they heavily (if at all) test these platforms against, because that's not a threat there's any expectation to face.

I think it's hilarious that our defense tracking infrastructure is too good at seeing stuff and that causes problems.

only took a couple of tries

That was a different UFO, the one over Lake Huron. This one was over Canada.

Isn't each missile $400k?

Each missile purchased puts food on the table for a defense contractor living in Chantilly, VA. (The military industrial complex welfare state is very lucrative as long as you keep your mouth shut, your head down, and obey)

No wonder they blamed F-35 programme as the main reason why American roads aren't fixed.

Which is always a stupid take. America is absurdly wealthy. We could burn half a trillion dollars a year in a big bonfire and still easily afford all the niceties of a modern nation like good infrastructure and healthcare.

We might have to actually tax a proportional amount from ultrarich and megacorps, but I'm perfectly fine with the people receiving 70% of all increase in wealth since the 50s paying a significant amount of tax.

Who did? The worst roads in America are all (meant to be) maintained with local/state money. The road surface of the federal highways are all in a reasonable state, although many bridges are sketchy. The F-35 isn't the reason an average country road in America looks like the surface of the Moon.

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