What are spy balloons, how do they work and why wouldn't China use a satellite? trends now
Chinese-American relations took a nosedive at the weekend, when the US destroyed a suspicious 'spy' balloon launched from Beijing.
The massive white orb had drifted across US airspace before being shot down by the US Air Force over the Atlantic on live TV on Saturday.
China claimed ownership of the balloon and insisted it was an unmanned weather surveillance aircraft that had veered off course, but the US remains unconvinced.
US officials have said it was being used for surveillance and intelligence collection, although it did not pose 'a military or physical threat'.
Here's what you need to know about spy balloons, from how they work to why they're being used as an alternative to satellites.
How does a spy balloon work? China's surveillance balloon is still shrouded in mystery to some extent, but experts say it could have sensors, a radar, and multiple cameras pointing down at Earth's surface. These could have powerful zoom and infrared capabilities to see in the dark
The huge, high-altitude Chinese balloon sailed across the US on Friday, drawing severe Pentagon accusations of spying and sending excited or alarmed Americans outside with binoculars
WHAT ARE SPY BALLOONS?
Spy balloons are huge, high-altitude balloons, each around the size of three buses, that are used as surveillance devices.
They provide an alternative surveillance option to satellites, which are at a higher altitude in low-Earth or medium-Earth orbit.
These spy balloons have high-tech equipment attached, including cameras and sensors.
China's spy balloon was spotted ahead of a planned trip to Beijing by US secretary of state Antony Blinken, which has now been postponed.
The balloon first entered US airspace over Alaska on January 28, before drifting over Canada and then back into the US.
A US fighter jet shot down the balloon over the Atlantic off South Carolina on Saturday, a response China described as an 'obvious overreaction'.
HOW DO THEY WORK?
Spy balloons contain gas such as hydrogen and helium that aid them to float with the wind, although US officials said this balloon had propellers to help steer it.
The Pentagon said the balloon was maneuverable and showed it could change course.
Spy balloons typically operate higher than commercial airplanes or even fighter jets and spy planes.
According to reports, China's balloon this week was registered floating at around 60,000 feet (11.3 miles), while most commercial airliners go up to 40,000 feet.
Surveillance balloons typically operate higher than commercial airplanes or even fighter jets and spy planes
The balloon was shot down Saturday off the coast of South Carolina by an F-22 fighter jet (pictured here in file photo)
According to the Washington Post, the lower part of the balloon has a 'ballonet', which can let in and out surrounding air.
If there's enough surrounding air in the ballonet, the whole balloon will sink, because this air is heavier than the helium above it.
The balloon can then rise and sink to catch winds that blow in the required direction, although this process can be aided by additional propellers.
WHAT SPY DEVICES WOULD THE BALLOON HAVE?
The surveillance balloons are equipped with cameras, sensors and radars, which point down at the ground, all powered by attached solar panels.
Sophisticated cameras allow them to take photographs of what's down on the Earth's surface, potentially with powerful zoom capabilities.
It's even likely these cameras can see outside of the visible part of the electromagnetic spectrum, such as infrared, letting them observe at night.
'If it's nighttime, a camera operating in the visible part of the spectrum is not going to show you anything – it's all going to be dark,’ said aerospace engineer Iain Boyd at the University of Colorado Boulder.
'But an infrared camera can pick up things from heat in the dark.'
The US was concerned because the balloon loitered over sensitive areas of Montana where nuclear warheads are siloed.
China insisted it was a weather surveillance aircraft, but according to the US it was carrying equipment in the pod under the balloon that is not usually associated with standard meteorological activities or civilian research.
IS THE SPACE BALLOON DANGEROUS?
The Pentagon said Thursday evening that the balloon was not a military or physical threat – in other words, it was not carrying weapons.
However, it's thought the primary danger to the US was potentially compromising the secrecy of sensitive sites.
The balloon's solar panels can be made out from this shot. China has claimed ownership of the device but has insisted it was a weather surveillance aircraft
The suspected Chinese spy balloon drifts to the ocean after being shot down off the coast in Surfside Beach, South Carolina, February 4, 2023
Even if the balloon was not armed, it posed a risk to the US, said retired Army General John Ferrari, a visiting fellow at the American Enterprise Institute.
The flight itself, he said, could be used to test America's ability to detect incoming threats and to find holes in the country's air defense warning system.
It may also have allowed the Chinese to sense electromagnetic emissions that higher-altitude satellites cannot detect, such as low-power radio frequencies which could help them understand how different US weapons systems communicate.
China's weather balloon excuse should be dismissed outright, said Oriana Skylar Mastro, an expert on Chinese military affairs and foreign policy at Stanford University.
'This is like a standard thing that countries often say about surveillance assets,'
