Venus balloons using water vapor Original Research Article

We propose an inflatable balloon floating below the Venus clouds by the use of water as the lifting gas. The balloon has a unique water vaporizing system that is simple, lightweight and small in size. The balloon shape is chosen to be cylindrical with a large aspect ratio for obtaining a sufficient surface area, which is used for a vaporizer instead of a large and heavy heat exchanging system. The envelope of the balloon has an outer layer for gas-barrier with a high-temperature resistant polymer film and an inner layer for keeping a lot of liquid water widely and thinly. Vaporization of the contained water is accomplished by the large heat flux from the high-temperature atmosphere in the large surface area. Balloon deployment and the inflation sequence are numerically examined. This type of balloon has a potential for a long duration in situ meteorological observation.