Global Aerospace Corporation (GAC) and its personnel have been developing revolutionary technologies for exploration of planetary atmospheres and surfaces from balloon altitudes. These technologies include altitude changing balloons at Venus, superpressure balloons at Mars and hot-air balloons at Titan.
Why is a balloon a good vehicle for planetary exploration?
An ideal vehicle would be able to gather data involving the planet’s atmosphere, surface and interior. Orbiters are limited in the quality of surface data they can obtain: data resolution is lower at their distance. Planetary entry probes can reach the surface and obtain far more data on surface composition, but they cannot travel to different parts of the planet’s surface – or, in the case of a rover, not very quickly. While planetary entry probes can analyze the atmosphere, they can do so for only a limited amount of time, during their entry trajectories. Landers are limited to analyzing only small parts of the planetary surface at a time.
Trajectory control allows a balloon to approach a planet’s surface more closely than an orbiter can, which enables collection of higher resolution images and more spectroscopic data. The balloon can also travel through the atmosphere slowly enough to gather information such as chemical composition and weather data.
What characteristics must such a balloon have?
All planetary balloons must be able to survive the trip from Earth to the target planet. The balloon material must be strong enough to undergo sterilization and then tight folding and packaging. Multiple g forces during launch introduce more stress, and in space the package (balloon, gas tanks and scientific instruments) must withstand low temperatures and exposure to electromagnetic and particle radiation. Upon entering the target planet’s atmosphere, the package has to withstand sharp deceleration forces and the balloon must then be deployed and inflated without tearing or tangling.
To gather scientific data, a planetary balloon must then be able to travel to different locations in a planet’s atmosphere as well as reach the surface. In order to do so, such a balloon has to have a way to change buoyancy. This can be accomplished by using a gas that will condense at a particular altitude and temperature, such that this altitude would be the maximum one for the balloon. The balloon will then sink until it reaches an altitude at whose temperature and pressure the liquid becomes a gas again and expands. Thus the balloon’s path oscillates among different atmospheric levels and hence can collect data on different conditions, helping to measure for example weather patterns. Such a balloon’s material must have low permeability to both the lifting and the phase change liquid/gases. Further requirements for the balloon and instruments plus packaging will depend on the planet or moon being explored.