 So, let us start today's talk. Good morning and welcome to all. Today's lecture is basically rooted in history. We have lots of lessons to learn from history and we will look at the historical perspective of LTA systems. The aim of this particular talk is to give you an exposure on how this technology started off, how it reached a peak and then there was a period in which there were lots of negative views about LTA systems and then it has bounced back recently. So, looking at the historical data available, one can classify as 5 main periods. Now, there is no reason for classifying in this manner and I am not a historian as you know. I have done this only on the basis of certain interesting events that took place. So, from ancient ages to the first world war is the first period which is a very long period as you can imagine and then between the two wars, there were certain things that took place, certain motivations were there to evolve this technology. During World War II, there were some applications which were very unique. After that, the technology went into a kind of hibernation. So, from 1940s to mid-80s, there was not much happening but then it bounced back in mid-80s due to a very interesting project and then from now on it is again up on the rise and that is why we are actually having this course. So, let us look at the first period. The first period started with the Chinese balloons and all of us are aware of these lanterns. We see them in all festivals including Wood, Indigo, Techfest. There have been many instances when these lanterns have been lit up in the sky. This is the most primitive LTA system. So, it all started. The first known LTA system if we forget about historical and unproved or undocumented information is the Chinese. They developed this Chinese lantern and the main application that they found for this was to use it for signaling during a military operation. And then the Mongolians have used it in some kind of a battle in 1291. So, that is how it started. Now, we will try to trace the historical developments of LTA systems using this map of the world and also the map will change slightly as the history progresses. But broadly speaking this is the kind of map from 1912 approximately. We use it for our explanation. So, you see that there is British Raj in India. So, Pakistan, Bangladesh, Sri Lanka and India are all under the British Rajs there. So, this is what was primitive 220 AD to 280 AD. After that, the first recorded flight of a balloon was made in Lisbon, Portugal. So, what happened is that there was a Brazilian Portuguese priest and he did this flight in front of the king. The maximum height achieved was only 4 meters and this was nothing but a paper balloon. But please understand even today to make a simple paper balloon filled with hot air and to make it rise 4 meters it is not a simple task. I am going to challenge you with an assignment very soon and you will realize that what seems very simple is not actually that simple. Anyway, so for historical purposes we had this first flight of a balloon in Europe and then our friend Henry Cavendish discovered this gas called hydrogen in 1766 and people realized that apart from being highly combustible this gas also is much lighter than air and therefore it can be used for some meaningful purposes. So, in 1783 we had the first flight as we all know from our school textbooks of the manned balloon flight. But interestingly the first flight ever was not a manned flight. Perhaps they were too scared and unsure whether it is safe. So, it is said that they took a duck, a rooster and a pig, put it on this balloon. They have no voice, they have no, you know they had no choice and it was raised up. When it went successfully they said oh this seems to be safe. So, then we had the manned flight which was in 1783. This was done by two brothers, the Montgolfier brothers as we call them. And interestingly the balloon was made of paper and the gas used was hot air. So, this was the first hot air balloon in history which carried human beings. This is 1783, many, many years after hydrogen has been discovered but because of combustibility of hydrogen people were worried whether we can use it and even now people worry whether hydrogen can be used as a lifting gas for man carrying applications. So, just 12 days after the first manned flight with the balloon, Professor Jacques Charles and Robert Brothers what they did is they used the gas produced discovered by Henry Cavendish. So, history has a very interesting information that something like 1.5 tons of sulphuric acid was poured over from 4 tons of aluminium or aluminium of some such compound or maybe metallic compound and the gas so produced was used to fill the balloon. But unfortunately the gas was very hot when it was produced it became cold very soon. So, there were issues in getting the lift. Similarly it did succeed and we had this bag filled with hydrogen carrying human beings. Now, let us move on to England now. This happened in France and as you know there is a very strong rivalry between England and France which is driven by technical development since many many years. So, therefore this rivalry took place also in the area of LTA systems. So, soon after the next year a Britisher created a balloon to fly in England. Then we had another Frenchman Jean-Pierre Blanchard. He is going to be appearing in few more slides in the future. He is a very interesting character very adventurous person did a few things. So, during that time one of the biggest challenges for human beings was to cross the English channel which is 24 miles distance between England and France. So, now we have built channel tunnel below the ocean to connect these two countries but at that time many aviation first were scored over across the channel flight. So, there was a challenge and Jean-Pierre was able to meet the challenge by doing across the channel flight using a balloon. And as you can see this is a hot air balloon because there is a throat on the bottom which is open and then we also had the first aviation disaster very soon. Aviation has a very bad name for disasters but if we start looking at numbers you will actually find statistically aviation is quite safe. Nevertheless it makes news. So, in this case now can you guess where it took place by looking at the flag? Anybody? It is not Scotland. It is Ireland. It is not Wales also that arrow is pointed slightly below the location but I thought the flag will give it away. It is Ireland. So, this took place in 1785. Just two years after the discovery and the first manned flight we had the first disaster in which a hot air balloon caught fire. Interestingly it is not hydrogen to be blamed here. It is hot air. And this happened in Ireland in a town called Toremore and this fire was so fierce that 130 houses were burnt down and this whole town was damaged. So, this town which is a part of this Ireland as you know is just next to UK or actually part of Northern Ireland is a part of UK. And this is this town in the middle of Ireland which had the first aviation disaster. Then the same gentleman was also instrumental in bringing LTA systems to USA. So, he did a kind of trans American flight in a hot air balloon and with that the technology started travelling to other countries. So, he is our friend who crossed the Atlantic Ocean to America and then flew within America. He also was instrumental in using an IC engine for the first time. Before that people were trying to use small steam engines to produce the required thrust force. He was the first to use IC engines but many, many, many years later. Yes, Amir. No, not in the balloon. He just crossed the Atlantic Ocean on a ship but very good question. It shows that you are attentive when you are listening because history can be little bit boring but I just want to make it interesting looking at the timeline and seeing slowly how the technology is progressing. So, he did not travel across the Atlantic Ocean using a balloon but within America he is able to travel across. Then we look at the first airship. Yes. Yes, now you can go around the world. Yeah, yeah, yeah. People have gone around the world in hot air balloon. There was a competition and our friend Richard Branson also took part in one competition but this record was broken very recently. There is a very interesting documentary on discovery which talks about around the world flight on a hot air balloon. So, now it is possible to fly but it is possible to fly because of technological developments, not that much in the area of LTS systems. Can you guess which technology enables people to fly across around the world with hot air balloons today? GPS is one thing. Yes, GPS will give you where you are but GPS will not enable you to do something, not that much. No, it is a hot air balloon. It is not going to be propelled. Yes, there is technological development in weather forecasting. It is said that they have developed a mathematical model which can predict the wind at any place in the world with 36 hours in advance. Accurately, very accurately. They could predict it for a long time but very accurate predictions for a 36 hour forecast and that information is not publicly available. It is a very well guarded secret. So, what they did is they were able to go around the world purely by controlling the flight of the balloon so that they would put it in the right wind pattern because it is all driven by wind. So, yes, other things are also very important including a capsule to keep the people protected from the atmospheric conditions at those altitudes. They actually want to hit the jet streams and then be driven by the jet streams. So, other things are also technically very important. In fact, Breitling, the company which makes these very famous chronographs, they were the people who sponsored this called Breitling Orbiter. So, I would urge you to look up on this particular thing and maybe somebody can give a link on the modal page about the documentary around the world flight in a hot air balloon.