Designing a simple airship
As the Vaihasaya gets close to Venus, the realm of Sukracharya, Meghanth is amazed by its beauty. It looks like a polished crystal ball with a thick atmosphere.
Meghnath: Grandpa, Venus looks similar to Earth in size, but it looks polished. Why??
Mayasura: What happens when you heat something at a high temperature?
Meghnath: It will melt.
Mayasura: Exactly… Venus’s surface temperature is 464°. That is why the it looks polished. Most things on Earth cannot survive on its surface. Much later in the future, in 1966, humans from Russia tried to land on the surface using the Venera 3 space probe. It crash landed. Venera 4,5 and 6 were crushed by the atmospheric pressure after successful entry. Some return of data showed that the atmospheric pressure is around 90 times that of the Earth’s. Venera 7 was designed with material that can withstand high pressure and it landed successfully in 1970. However, it was crushed 23 minutes after successful landing, and showed that the surface temperature was 455° to 475°.
Meghnath: But, Grandpa, guru Sukracharya seems to have a huge city floating here already. Can’t this knowledge be carried to the future?
Knowledge transfer
Mayasura: No, it is not possible as most humans with this knowledge were destroyed by various cataclysmic events on Earth. In 1982 and 1985, the Soviet Union launched Vega 1 and 2 respectively, where they deployed a floating helium balloon (Aerostat), which was active for more than 46 and 60 hours.
Meghnath: Grandpa, what are aersotat vehicles and how do they work?
Mayasura: These are aircraft that lift up or defy gravity with the help of density variation. The average density of the craft (airships, hot air balloon and so on) is lower than the density of atmospheric air, which provides buoyancy to float.
Meghnath: What is buoyancy?
Mayasura: When you jump inside water, have you ever felt being pushed up? That is buoyancy, an upward force exerted by a fluid that opposes the weight of the object that tries to immerse.
Meghnath: So, like how we swim in water, airships and hot air balloons swim in air?
Mayasura: Yes. Since the atmospheric density and pressure is too high in Venus, it is easy to build an aerostat.
While talking, Mayasura walks towards the cockpit, takes
Ravana: I can handle this, Uncle. Looks like Meghnath is going to trouble you with more questions.
Ravana and Mayasura shift places, and Mayasura comes to the fuselage.
Meghnath: How did this vimana inflate, grandpa?
Mayasura: That’s due to the compressed helium stored in a canister. We released it to make sure the Vaihasaya can float on Venus.
Meghanth: We can also use hydrogen, right?
Mayasura: Yes, but it is highly inflammable. Helium is an inert gas, and hence safe.
Meghnath: I read that all inert or noble gases are non-reactive and non-corrosive, due to a stable atomic structure.
Mayasura: Yes, I released it at the height of 53km.
Meghanth: Anything specific about this altitude?
Mayasura: Yes. At 50-60km, Venus is more Earth-like in pressure and temperature.
Meghnath: Then, it will be easy to colonise. Also, grandpa, can you teach me design a simple airship??
Mayasura: It needs only four parts. First, an Envelope to fill the air. Then the Gondola, a cabin for people or payloads. Next, control surfaces like fins and rudder to control direction. Finally, a small engine (electric, piston and so on) to generate airflow for direction control.
Meghnath: It seems simple. Why are people trying to build complicated aerodyne vehicles like aeroplanes and helicopters?
Mayasura: Well, for simple payloads, aerostats are fine. But, for higher payloads, we need to design bigger vehicles. Speed also matters. It is also highly unsafe for defence purpose as well.
Meghanth: This place is full of science, which is new to me, Grandpa. I am so excited about meeting Sukracharya.
Vaihasaya slowly lands in Tripura, on top of a beautifully built palace.
…to be continued
The author is the founder and CEO of Vaayusastra Aerospace, an IIT-Madras incubated ed-tech startup that offers Air Science workshops for children between five and 14 years.
There are various parts to an airship. Have you come across any of them online or in your books? Well, in case you haven’t, here is a chance for you to get to know about the parts that make up an airship. In the drawing below, drag and drop the words to the corresponding arrows, and voila, mystery solved.