If all goes according to plan, in 1995, vehicles made on Earth will lift off from another planet for the first time. The planet is Mars, and the vehicles will be descendants of the first flying machine, the balloon. Conceived and developed by a unique international team, two Mars balloons will send back to Earth a rich data stream of photographs and measurements. During their 10-day lives, the balloons will explore some thousand miles of the Martian surface and make 20 vertical probes of the atmosphere, providing scientists with the data necessary for further exploration of the planet.
The team that is designing and building the Mars balloons is almost as interesting as the mission itself. The Soviet Union has taken the project's leadership, assisted by the French and an amalgam of U.S. engineers sponsored by the Planetary Society (TPS). TPS, the world's largest non-government organization dedicated to the advancement of space flight and the exploration of the planets, recently signed agreements with both the French and the Soviet space agencies. These agreements make TPS an active participant in the conceptualization and design of the Mars balloon. Founded in 1980 by space scientists Carl Sagan, Bruce Murray, and Louis Friedman, TPS now has over 125,000 members worldwide. Working together, this team plans to launch the first mobile robotic explorers to the Red Planet.
First Venus, Now Mars
Scientists have long recognized the value of planetary exploration by balloon. During the 1986 Venus/Halley Comet mission, two Soviet/French balloons were successfully injected into Venus' atmosphere, leaving no doubt as to their capability. That mission, the brainchild of Jacques Blamont of the French Space Administration (CNES) and Roald Sagdeev, then director of the Soviet Space Research Institute (IKI), confirmed the utility of balloons in planetary exploration.
The Venus balloon mission took almost 20 years to bring to fruition. Starting in 1967 with a proposal by Blamont, then director of the Service d'Aeronomie, the leading space research laboratory of France, the mission was originally designed to carry two larger thermal balloons to Venus. These plans were completely changed when, at the suggestion of Sagdeev, the Soviets created the VEGA mission, merging the Venus balloons with a mission to Halley's comet. As a result, the payload allocated for the Venus portions of the mission was significantly reduced. This, in turn, required reduction of the balloon size and the payloads.
As the dual Soviet spacecraft flew past Venus on its way to intercept Halley's comet, the two balloons were successfully deployed on June 13 and June 15, 1985. Each was injected into the dark side of the planet, achieving stable float altitude some 34 miles above the surface.
The superpressure balloons had limited vertical mobility, moving up and down only 650-1,000 feet, and their smaller payload limited battery lifetime to only 48 hours. Nonetheless, they collected valuable data, measuring winds of up to 125 miles per hour during the mission, and provided the basis for the next step in cosmic ballooning - the flight to Mars.
The surface area of Mars is both vast (roughly equivalent to Earth's land area) and treacherous (chasms that dwarf the Grand
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