What is a spy balloon? The WW-II relic China has repurposed (GS Paper 3, Science and Tech)
Why in news?
- Days ahead of a planned trip to China by US Secretary of State Antony Blinken, a Chinese spy balloon has been reported flying over the United States.
- While the US Air Force readied fighter jets to shoot it out of the sky, President was advised against doing it for fear of debris.
- The United States took custody of the balloon when it entered U.S. airspace and had observed it with piloted U.S. military aircraft.
What are spy balloons?
- The high-altitude balloons are the same as weather balloons deployed across the world to monitor changes in the local weather of the region. However, when it comes to spy balloons, their purpose is changed. These balloons operate 24,000-37,000 meters above the ground.
- The altitude that these balloons fly at is well above where commercial air traffic flies. Airliners almost never fly higher than 40,000 feet. The highest-performing fighter aircraft typically do not operate above 65,000 feet, although spy planes such as the U-2 have a service ceiling of 80,000 feet or more.
- The advantages of balloons over satellites include the ability to scan wide swathes of territory from closer in, and to be able to spend more time over a target area.
- Unlike satellites, which require space launchers that cost hundreds of millions of dollars, balloons can be launched cheaply.
WWII era:
- Spy balloons are not new and have been in use since World War II.
- Just after the end of the war, the US military started exploring the use of high-altitude spy balloons, which led to a large-scale series of missions called Project Genetrix.
- The project flew photographic balloons over Soviet bloc territory in the 1950s, according to government documents.
- During World War 2, the Japanese military tried to loft incendiary bombs into U.S. territory using balloons designed to float in jet stream air currents. While it did not damage military targets, it did cause civilian causalities.
Why is the matter sensitive?
- The spy balloon was trying to fly over the Montana missile fields, but the U.S. has assessed that it has “limited” value in terms of providing China with intelligence.
- It was not clear what the military was doing to prevent it from collecting sensitive information or what will happen with the balloon if it isn’t shot down.
Scientists split seawater without pre-treatment to produce green hydrogen
(GS Paper 3, Environment)
Why in news?
- Recently, the researchers have successfully split seawater without pre-treatment to produce green hydrogen.
Details:
- The researchers split natural seawater into oxygen and hydrogen with nearly 100 per cent efficiency, to produce green hydrogen by electrolysis.
- They used a non-precious and cheap catalyst in a commercial electrolyser. A typical non-precious catalyst is cobalt oxide with chromium oxide on its surface.
Seawater electrolysis:
- Seawater is an almost infinite resource and is considered a natural feedstock electrolyte. This is more practical for regions with long coastlines and abundant sunlight.
- However, it is not practical for regions where seawater is scarce.
- Seawater electrolysis is still in early development compared with pure water electrolysis because of electrode side reactions, and corrosion arising from the complexities of using seawater.
Significance:
- It is always necessary to treat impure water to a level of water purity for conventional electrolysers including desalination and deionisation, which increases the operation and maintenance cost of the processes.
- The work provides a solution to directly utilise seawater without pre-treatment systems and alkali addition, which shows similar performance as that of existing metal-based mature pure water electrolyser.
Way Forward:
- They will work on scaling up the system by using a larger electrolyser so that it can be used in commercial processes such as hydrogen generation for fuel cells and ammonia synthesis.
