EXPLAINED: All About Spy Balloon As US Probes 'Chinese' Surveillance Device

The Pentagon is tracking a suspected Chinese surveillance device over its airspace, but this isn't the first time such a balloon has been seen over the US.  

The US Department of Defense has tracked down the "intelligence-gathering" suspected Chinese spy balloon flying over American airspace. The development comes days ahead of the Beijing visit of Secretary of State Antony Blinken.

"The United States government has detected and is tracking a high-altitude surveillance balloon that is over the continental United States right now," Pentagon Press Secretary, Brigadier General Patrick Ryder said in an official statement.

"NORAD (North American Aerospace Defense Command) continues to track and monitor it closely," he said, adding the balloon was spotted over Montana on Thursday and is “said to be the size of three buses”.

“Once the balloon was detected, the US government acted immediately to protect against the collection of sensitive information,” Ryder said.

The incident comes on the back of escalating tensions between the two countries over a series of issues. While China said it is working to "verify" reports it flew a spy balloon over the US, reported news agency AFP.

US Response Over Surveillance Balloon

The Pentagon is keeping a track of the suspected Chinese surveillance balloon over its airspace. In a statement, Pentagon said: “The balloon is currently travelling at an altitude well above commercial air traffic and does not present a military or physical threat to people on the ground.”

Senior US officials advised President Joe Biden against shooting it down as the debris could pose a safety threat, reported Reuters.

Pentagon says it is monitoring a spy balloon and this isn't the first time such a balloon has been seen over the US.  

On Thursday, Canada’s National Defence also gave a statement saying it was tracking a “potential second incident”.

What Are Spy Balloons?

A spy balloon is typically a piece of spying equipment for instance camera attached beneath a balloon flying in space under the influence of wind currents, the British daily 'The Guardian' reported. The equipment attached to such balloons may be powered by radar or solar energy. Spy balloons can fly at 24,000 metres or 37,000 metres. This height is above commercial air traffic as airlines never fly higher than 12,000 metres.

Reason For Using Spy Balloons Over Satellites

Explaining the use of spy balloons, John Blaxland, Professor of International Security & Intelligence Studies at the Australian National University, said lasers or kinetic weapons are now being invented to target satellites.

Hence there is a resurgence of interest in balloons, Blaxland told 'The Guardian'.

He explained that the balloons don’t offer the same level of persistent surveillance compared to satellites, but are easier to retrieve, and much cheaper to launch. 

Balloons can track more territory from a lower altitude and stay for a longer period in a given area because they move more slowly than satellites, according to a 2009 report to the US Air Force’s Air Command and Staff College.

When Were They First Used?

For the first time, spy balloons were first used in the 1860s during the American civil war.

“At that time Union men in hot air balloons, binoculars at the ready would try to gather information about Confederate activity further away. They sent signals back via morse code or a “piece of paper tied to a stone”, says Blaxland.