5 ms·

Im pretty impressed that it made it all the way across the continent in a couple days, i had no idea high altitude balloons could move that fast.

pixl97 4y ago
Technically the ballon isn't moving itself in anyway at all, it instead is depending on the wind. As the atmospheric pressure lowers the maximum speed of the wind can increase greatly. For example the speed of the jet stream commonly exceeds 275 miles per hour. It looks like the strongest jet winds were closer to canada, had the jet been in the US it could have made it across the country in a day.
- ineedasername 4y ago
  There was mention by the Chinese that is had some motive power of its own, or at least strongly implied when their PR said some the thing like “limited maneuvering capability”. That seems to indicate that it had some. It would a bit surprising if a payload the size of 2-3 school buses wasn’t outfitted with a reasonable amount of controllability, at least some control surfaces even if they inexplicably excluded even minimal and limited propulsion.
  - NegativeLatency 4y ago
    Probably ballast control to select favorable winds at different altitudes A reserve of buoyant gas and/or some weights to drop
  - deleted 4y ago
    [deleted]
  - kelnos 4y ago
    "Maneuvering capability" probably means that it can affect its course (probably by ascending or descending to find more favorable winds), not speed.
  - seanmcdirmid 4y ago
    Not much they could do there. Highly likely just up and down: https://www.scientificamerican.com/article/chinese-spy-balloon-has-unexpected-maneuverability/ https://www.scientificamerican.com/article/chinese-spy-ballo... Unless the Chinese have balloon control tech we’ve never even fathomed before. That would be way scarier than the balloon itself.
  - letmevoteplease 4y ago
    "Officials said the balloons are part of a fleet that China uses for surveillance, and they can be maneuvered remotely through small motors and propellers." https://apnews.com/article/politics-united-states-government-china-antony-blinken-51e49202f2a0a50541cde059934c4cfb https://apnews.com/article/politics-united-states-government...
- hackernewds 4y ago
  Imagine the earth is also spinning under the balloon?
  - jacquesm 4y ago
    That doesn't really matter, but the jetstream does matter. That's why it is going West-to-East to begin with.
  - californical 4y ago
    It doesn’t matter for the same reason that the earth doesn’t go flying out from under you if you jump into the air. Yes, it’s spinning, but so is everything else, so it nets to 0
Waterluvian 4y ago
Yeah, atmospheric winds and the jet stream are impressive forces. There is a lot of convection going on up there.
geerlingguy 4y ago
Winds are seriously fast at higher altitudes — check out the different wind speeds using the "height" option on this site: https://earth.nullschool.net/#current/wind/surface/level/orthographic=-96.05,37.86,1316 https://earth.nullschool.net/#current/wind/surface/level/ort...
- Choco31415 4y ago
  I poked at the website a bit and the fastest wind speed I could find in the world was roughly 360 km/h. Over the US there were some 250 km/h winds. That is interesting!
jacquesm 4y ago
The jetstream is fast enough that it factors into any flight at altitude when it comes to fuel estimations and path calculations, up to 12% difference or so iirc.
- mlindner 4y ago
  Indeed this is really obvious to anyone who regularly travels to California and back to the somewhere on the eastern half of the US (or vice versa). The time it takes for the east bound leg is way faster than the west bound leg. Going from San Francisco to Detroit for example is about an hour faster on the east bound direction.

pixl97 4y ago

Technically the ballon isn't moving itself in anyway at all, it instead is depending on the wind. As the atmospheric pressure lowers the maximum speed of the wind can increase greatly. For example the speed of the jet stream commonly exceeds 275 miles per hour. It looks like the strongest jet winds were closer to canada, had the jet been in the US it could have made it across the country in a day.

ineedasername 4y ago
There was mention by the Chinese that is had some motive power of its own, or at least strongly implied when their PR said some the thing like “limited maneuvering capability”. That seems to indicate that it had some. It would a bit surprising if a payload the size of 2-3 school buses wasn’t outfitted with a reasonable amount of controllability, at least some control surfaces even if they inexplicably excluded even minimal and limited propulsion.
- NegativeLatency 4y ago
  Probably ballast control to select favorable winds at different altitudes A reserve of buoyant gas and/or some weights to drop
- deleted 4y ago
  [deleted]
- kelnos 4y ago
  "Maneuvering capability" probably means that it can affect its course (probably by ascending or descending to find more favorable winds), not speed.
- seanmcdirmid 4y ago
  Not much they could do there. Highly likely just up and down: https://www.scientificamerican.com/article/chinese-spy-balloon-has-unexpected-maneuverability/ https://www.scientificamerican.com/article/chinese-spy-ballo... Unless the Chinese have balloon control tech we’ve never even fathomed before. That would be way scarier than the balloon itself.
- letmevoteplease 4y ago
  "Officials said the balloons are part of a fleet that China uses for surveillance, and they can be maneuvered remotely through small motors and propellers." https://apnews.com/article/politics-united-states-government-china-antony-blinken-51e49202f2a0a50541cde059934c4cfb https://apnews.com/article/politics-united-states-government...
hackernewds 4y ago
Imagine the earth is also spinning under the balloon?
- jacquesm 4y ago
  That doesn't really matter, but the jetstream does matter. That's why it is going West-to-East to begin with.
- californical 4y ago
  It doesn’t matter for the same reason that the earth doesn’t go flying out from under you if you jump into the air. Yes, it’s spinning, but so is everything else, so it nets to 0

Waterluvian 4y ago

Yeah, atmospheric winds and the jet stream are impressive forces. There is a lot of convection going on up there.

geerlingguy 4y ago

Winds are seriously fast at higher altitudes — check out the different wind speeds using the "height" option on this site: https://earth.nullschool.net/#current/wind/surface/level/orthographic=-96.05,37.86,1316 https://earth.nullschool.net/#current/wind/surface/level/ort...

Choco31415 4y ago
I poked at the website a bit and the fastest wind speed I could find in the world was roughly 360 km/h. Over the US there were some 250 km/h winds. That is interesting!

jacquesm 4y ago

The jetstream is fast enough that it factors into any flight at altitude when it comes to fuel estimations and path calculations, up to 12% difference or so iirc.

mlindner 4y ago
Indeed this is really obvious to anyone who regularly travels to California and back to the somewhere on the eastern half of the US (or vice versa). The time it takes for the east bound leg is way faster than the west bound leg. Going from San Francisco to Detroit for example is about an hour faster on the east bound direction.