At first, Santos-Dumont worked with hot air balloons. One problem with hot air balloons was that they were very difficult to steer. After making a few hot air balloons that could go up and down well, Alberto Santos-Dumont decided to build a good steering system. He built eleven hot air balloons that could be steered, called dirigibles, between 1898 and 1905. His third balloon in this project, "Santos Dumont No. 3", worked. He was able to steer it around the Eiffel Tower and land where he meant to land. His "Santos Dumont No. 6" won the Deutsch de la Meurthe prize.