Possible themes in 'aeronauts based on a true story' are adventure and the pursuit of knowledge. The aeronauts were on an adventure, going where few had gone before. Their flights were also about learning more about the world above us. Additionally, a theme could be the human spirit's ability to overcome challenges. They had to overcome technical, physical, and mental challenges, which is a great testament to the human spirit.
The themes could include exploration. Just like explorers on land, these aeronauts were exploring a new frontier - the sky. Also, perseverance is likely a theme. They would have faced many setbacks but kept going. There might also be a theme of scientific discovery, as their flights contributed to the understanding of things like air currents and weather patterns.
One possible theme could be courage. The aeronauts must have been very brave to take on the unknown of the skies in the early days. Another theme might be innovation, as they were constantly trying out new ideas and techniques in flight.