GS Advance Program for UPSC Mains 2025, Cohort - 1 Starts from 24th October 2024 Click Here for more information
Source: This post on HAPS (High-Altitude Pseudo-Satellite vehicles) has been created based on the article “Why India wants to develop high-altitude pseudo-satellite vehicles, powered by the Sun” published in “Indian Express” on 14th February 2024.
UPSC Syllabus Topic: GS Paper 3 Science and Technology – Developments and their applications and effects in everyday life.
News: The article discusses HAPS (High-Altitude Pseudo-Satellite vehicles) and its applications and advantages. It also highlights the engineering challenges in developing HAPS?
Read more about High-Altitude Pseudo-Satellite vehicles (HAPS) here.
Background:
Last week, the Bengaluru-based National Aerospace Laboratories (NAL) successfully flew a prototype of a new-generation unmanned aerial vehicle (UAV) that is being seen as a huge technology breakthrough.
Why was this UAV different?
It can fly at great heights, about 20 km from the ground. It runs entirely on solar power and can remain in the air for months.
Such UAVs belong to a class of flying objects called HAPS (high-altitude pseudo-satellite vehicles), or HALE (high-altitude long-endurance vehicles).
HAPS are meant to fly in the stratosphere (region between 17 and 23 km above the earth’s surface) since wind speed is very low and ideal for light-weight aircraft to remain stable.
No country has mastered this technology yet. However, the successful test flight shows that India has capabilities like some other countries trying to develop this technology.
What are the possible uses of HAPS?
- Surveillance and monitoring.
- Disaster management.
Why are HAPS better than currently available technologies?
1) Comparison with Drones: Normal UAVs, or drones are mostly battery-powered and cannot remain in the air beyond a few hours. They fly at relatively low levels, because of which their vision is restricted to small areas.
However, it can easily keep an eye over 200 sq km of area.
2) Comparison with Satellites: Satellites in low-earth orbits are continuously moving with respect to Earth. They cannot constantly keep an eye on the target area. Geostationary satellites (36,000 km above the ground) can keep a constant gaze over one area but are expensive, and once deployed, cannot be repurposed or reoriented.
However, HAPS can be easily redeployed over another location, or can be reequipped with a different payload.
What are the engineering challenges in developing HAPS?
1) Solar Power issue: The biggest challenge is to generate enough solar power to keep the aircraft flying, the payloads operating, and the batteries charging.
2) High Battery Density Required: Because of limitations of space and weight, solar cells and batteries need to have very high efficiency (in terms of energy density – the amount of energy stored in a battery in proportion to its weight).
3) Design-related challenges: The aircraft needs to be extremely lightweight to minimize the power requirement, but it also has to be stable at the same time.
4) Low Temperatures: Temperatures in the stratosphere can drop to -50 degree Celsius or lower. Electronics need to be kept warmer, and this forms an additional burden on power resources.
5) Low Air Density: Air density in the stratosphere is just about 7% of what it is at sea level. That creates complications in producing lift and thrust.
Question for practice:
What are HAPS (High-Altitude Pseudo-Satellite vehicles)? Why are they better than currently available technologies? What are the challenges in developing HAPS?
