# We have NO method of capturing a slowly flying balloon? **URL:** \ **Category:** Factual Questions\ **Created:** [February 14, 2023, 7:30pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792 "2023-02-14T19:30:47Z")\ **Posts on this page:** 16\ **Page:** 4
**Author:** ![fordgt100](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@fordgt100](https://boards.straightdope.com/u/fordgt100)\ **Post date:** [February 28, 2023, 10:35pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/61 "2023-02-28T22:35:32Z")
I’m sure eBay or Etsy sells an inexpensive General Purpose Balloon Retirement System for cheap. Probably made in China though. So… ---
**Author:** ![EdwardFound](https://avatars.discourse-cdn.com/v4/letter/e/4af34b/32.png) [@EdwardFound](https://boards.straightdope.com/u/EdwardFound)\ **Post date:** [March 1, 2023, 12:48am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/62 "2023-03-01T00:48:52Z")
How about a rocket that’s fired above the balloon and deploys a drone hanging from a parachute or parafoil. The drone couldn’t fly at that altitude, but would have enough thrust to guide its descent until the chute cords snagged onto the balloon. As it dragged the balloon down into denser air it would gain enough thrust to pull the balloon towards a safe fall spot - or maybe into range of a plane or helicopter capable of snagging the balloon. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [March 1, 2023, 12:58am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/63 "2023-03-01T00:58:43Z")
> [@Al128](#): > > in a traditional fixed-wing airplane, I assume, there is a relationship between speed and service ceiling … What you are referring to is commonly called the coffin corner: > **[Coffin corner (aerodynamics)](https://en.wikipedia.org/wiki/Coffin_corner_(aerodynamics))** > > Coffin corner (also known as the aerodynamic ceiling or Q corner) is the region of flight where a fast but subsonic fixed-wing aircraft's stall speed is near the critical Mach number, at a given gross weight and G-force loading. In this region of flight, it is very difficult to keep an airplane in stable flight. Because the stall speed is the minimum speed required to maintain level flight, any reduction in speed will cause the airplane to stall and lose altitude. Because the critical Mach num Th... There is an upper and lower airspeed limit when it comes to wing lift: the lower limit from stall speed (too slow, and the wings need more angle of attack than they can support), and the critical Mach number at the upper end (too fast, and you get shock waves that reduce lift). Between these is where you can fly safely, but because the two values approach each other as you increase altitude, there’s an upper limit to your service ceiling. The U-2 famously spends much of its time in the coffin corner, with maybe a 5-knot margin on either side. And it does mean that there’s no such thing as a low-speed flyby–or a high-speed one, either. ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [March 1, 2023, 1:43am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/64 "2023-03-01T01:43:05Z")
thx, interesting to learn that the higher up you are, the less degrees of freedom concerning your airspeed, you have… … but then again (after a few moments of analysis) it makes sense that in an ever thinner medium you need to fly ever faster to achieve the same amount of lift to keep you “bouyant”. … until this ever-faster gets you to run into buffetting speed - that starts delaminating the air-flow over your wings I assume there are tricks to stretch this coffin corner (e.g. var. wing geometry or so) ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [March 1, 2023, 2:41am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/65 "2023-03-01T02:41:16Z")
> [@Al128](#): > > I assume there are tricks to stretch this coffin corner (e.g. var. wing geometry or so) It seems you can move it up higher and faster, but it’s still a corner. Here’s the SR-71’s flight envelope, showing the corner still exists at Mach 3.2 and 85,000 feet. [![](https://i.stack.imgur.com/pI67e.gif) ](https://i.stack.imgur.com/pI67e.gif) ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [March 1, 2023, 1:29pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/66 "2023-03-01T13:29:56Z")
I imagine a lot of it has to do with exactly what path the cannon rounds took- if they transited the lower half and didn’t actually poke holes in the part that was holding the gas in, it might not actually let much out. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 1, 2023, 10:16pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/67 "2023-03-01T22:16:41Z")
On thinking about this some more, holes in the bottom half of a balloon wouldn’t matter because they’re letting lift gas out-- They’d matter because they’d let ordinary air in. ---
**Author:** ![gnarator](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gnarator/32/8266_2.png) [@gnarator](https://boards.straightdope.com/u/gnarator)\ **Post date:** [March 1, 2023, 10:35pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/68 "2023-03-01T22:35:38Z")
> [@Dr.Strangelove](#): > > The U-2 famously spends much of its time in the coffin corner, with maybe a 5-knot margin on either side. And it does mean that there’s no such thing as a low-speed flyby–or a high-speed one, either. Correct, stall speed is 10 knots less than maximum speed at altitude (post #15). The U2 is a notoriously difficult airplane to fly, requiring great skill and concentration to fly within such narrow margins, navigate the correct route, and run the cameras. At high altitudes it requires a delicate touch, but when it descends to thicker air it takes some strength to move the controls. The plane was made for a specific purpose, so its structure is quite delicate and lightweight. It won’t be carrying missiles or snagging any balloons. ---
**Author:** ![Ssounder](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@Ssounder](https://boards.straightdope.com/u/Ssounder)\ **Post date:** [March 2, 2023, 2:37am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/69 "2023-03-02T02:37:45Z")
I hope the US doesn’t spend any time or $$$ developing a system that can capture a slow flying balloon. If it’s in our airspace and not registered, and if NORAD deems it a plausible threat, I support their decision to shoot it down. I don’t see any political traction going on demanding that we recover them all and report every detail. If the owners are acting honestly and with goodwill, they should report that they lost a balloon and own up to their lack of proper registration/communication. Then list the steps they would take to avoid future incidents. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 2, 2023, 2:51am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/70 "2023-03-02T02:51:21Z")
We’re not trying to capture the balloons to be nice to the balloons’ owners. We’re trying to capture the balloons so we can figure out what the heck they’re doing, because the owners aren’t going to tell us. ---
**Author:** ![Ssounder](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@Ssounder](https://boards.straightdope.com/u/Ssounder)\ **Post date:** [March 2, 2023, 2:56am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/71 "2023-03-02T02:56:05Z")
Imo if it’s a plausible threat, shoot 1st and ask questions later. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [March 2, 2023, 3:08am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/72 "2023-03-02T03:08:40Z")
Would flying a version of the Reaper military drone kamikaze-style through the fabric of the balloon do the trick? They have a [ceiling of 50,000 ft](https://en.wikipedia.org/wiki/General_Atomics_MQ-9_Reaper#Specifications_(MQ-9A)), so they should be able to reach the neighborhood of the balloons, and they’re relatively slow. In terms of cost, it looks like Spain bought 4 unarmed drones (and 2 ground stations) for 25 million Euros and planned a 5-year operating budget of 171 million Euros. That was back in 2015. So presumably one could piggyback off of existing US military drone operations infrastructure, strip down an unarmed drone to even lower (i.e., cheaper) limits, and buy and operate balloon recon-and-kill units for a significantly lower cost than that. ---
**Author:** ![Ssounder](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@Ssounder](https://boards.straightdope.com/u/Ssounder)\ **Post date:** [March 2, 2023, 3:23am UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/73 "2023-03-02T03:23:36Z")
Even a simple weather balloon _transmits_ it’s findings back to it’s host via radio signals. The DOD is absolutely intercepting these transmissions and analyzing them before deciding whether they pose a possible threat to North American sovereignty. Q: Why would an innocent weather balloon use an encryption key that the DOD can’t read? ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [March 2, 2023, 2:29pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/74 "2023-03-02T14:29:51Z")
> [@Ssounder](#): > > Q: Why would an innocent weather balloon use an encryption key that the DOD can’t read? If it’s just sending out numerical info with no text, which is what you’d expect if it’s a research instrument, it’ll be pretty opaque to everyone except the people who sent it out. Doesn’t matter if it’s encrypted or not. ---
**Author:** ![Steve\_MB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steve_mb/32/5339_2.png) [@Steve\_MB](https://boards.straightdope.com/u/Steve_MB)\ **Post date:** [March 2, 2023, 2:36pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/75 "2023-03-02T14:36:35Z")
> [@Ssounder](#): > > Q: Why would an innocent weather balloon use an encryption key that the DOD can’t read? Because with modern processing, there’s just no point in bothering with weak encryption if you’re going to bother with encryption at all (which is usually the case, given that encryption is useful for things like ID verification as well as preventing unauthorized access). ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [March 2, 2023, 2:42pm UTC](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792/76 "2023-03-02T14:42:38Z")
These days, it’s more remarkable if a device does not encrypt its communications. [Previous page](https://boards.straightdope.com/t/we-have-no-method-of-capturing-a-slowly-flying-balloon/979792.md?page=3)