GS Paper - II

Taiwan said on 25 November 2024 it had detected a Chinese balloon over the sea northwest of the island. It is the first time since April that Taiwan has reported such an incident. The balloon was sighted around 111 km to the north Keelung port. According to Taiwan’s Defence Ministry the balloon entered the island’s air defense identification zone. The incident comes as China maintains pressure on Taiwan, as Beijing regards Taiwan as part of its own territory rather than an independent nation.

High-altitude balloons

• Balloons have been in frequent use for several decades now, though the first uses go back at least 200 years.
• They are used mainly for scientific purposes but increasingly for tourism and joy rides, surveillance, and disaster relief and rescue.
• The bigger balloons can be as large as a football stadium, go up to 40-50 km from the ground, and carry a few thousand kilograms of payloads.
• Most of these are built of thin sheets of polyethylene, like the common plastic bags, and are filled mostly with helium gas.
• Balloons can stay in flight from anywhere between a few hours to a couple of months. Those that are meant to remain in air for long and go higher up in the atmosphere are made of more advanced materials for increased sturdiness.
• Balloons typically have a basket attached to them, called gondolas, that carry instruments or human beings. In unmanned flights, the gondolas are also attached to a parachute.
• Once the job of the balloon is done, a device in the gondola is triggered to snap its ties with the balloon as well as create a rupture in the fabric of the balloon.
• With the help of the parachute, the gondola then glides down to the earth, followed by the ruptured balloon.
• The possible landing zone is calculated ahead of the flight based on weather conditions.

Scientific missions

• The most common use of balloons is in scientific research. In a way, balloons equipped with instruments were able to perform the functions of a satellite before the space age dawned.
• Even in the times of advanced satellites, there are situations in which balloons are considered more suitable.
• Weather agencies routinely use balloons to make measurements – of air temperature, pressure, wind speed and direction, aerosol concentrations.
• Because of the high altitudes that today’s giant balloons can attain, they are considered useful for astrophysicists and even space agencies.
• These are relatively clear spaces, much above the heights at which airplanes fly and far below the nearest orbits, about 200 km from earth, where satellites are placed.
• Very often, they offer better opportunities to observe specific parts of the earth, and are also thousands of times cheaper than satellites.
• Moreover, because the balloons are brought down after their job is done, the instruments used are recoverable and reusable.
• NASA has a full-fledged balloon programme that does four-five launches every year. Several universities and research institutions also use balloons for research work.
• Balloon-based experiments have resulted in at least two Nobel prizes for Physics, in 1936 and 2006.

Surveillance

• High-altitude balloons are tempting vehicles for espionage operations, though their use is not known to be very common.
• Drones and satellites are used more frequently, and spy planes have been in use since World War I. But here again, balloons have certain advantages. They can hover over an area for a prolonged time.
• Big balloons can carry a few thousand kilograms of payload, which means they can be packed with spying instruments.
• The biggest advantage is the greater prospect of their remaining undetected. Because of their relatively slow movement, balloons are mostly flagged as birds by defence radars, thus escaping attention. In fact, the US has now said it will recalibrate its radar systems to detect slow-moving objects.
• Balloons lack sophisticated navigation systems of an aircraft, drone or satellite, being largely on the mercy of wind speed and direction.
• But the balloon that was downed on 4 February 2024 seemed to have a solar panel attached to it, which has given rise to the possibility of it powering an onboard propulsion device.

Ballooning in India

• Scientific balloons have been used in India for more than 70 years, the first one having been sent in 1948 by Homi Bhabha for cosmic ray research.
• The Mumbai-based Tata Institute of Fundamental Research (TIFR) started balloon fabrication work in the 1950s, and several balloon flights were launched from Mumbai and Hyderabad.
• Sometimes later, in 1969, the TIFR opened a full-fledged Balloon Facility in Hyderabad, which remains India’s largest such facility today.
• Scientists from different research institutions have used it to launch more than 500 flights till now. It is regularly used by the space institutions under ISRO, and weather research institutions like the Indian Institute of Tropical Meteorology in Pune.
• Institutions like the Bengaluru-based Indian Institute of Astrophysics and Hyderabad’s Osmania University, as well as some private educational institutions, also have balloon programmes.