Venus Balloon Probe to Visit Chemically Violent World

Earth's nearest planetary neighbor, Venus, is similar to our world in size, but its environment it truly alien. The weather on Venus is ruled not by water, but by battery acid. Venus seems endowed with more than its share of sulfur, and that sulfur combines with other elements to form complex things like sulfuric acid hazes. Acid rain is a real issue on Venus.

What can we learn from our cosmic neighbor, and how can it help us better care for our own world?

For the answer to this and other questions, researchers like the Jet Propulsion Laboratory's Viktor Kerzanovich have been working to send an ambitious balloon mission to the hothouse world. The probe is called VALOR, for Venus Atmospheric Long-duration Observatory for in-situ Research.

In interviews conducted by the author with several project scientists for a forthcoming book, Kerzanovich said:

We have been working for several years to fly a new type of balloon on Venus that will last for about 30 days, so we hope that this will be a very spectacular and very science-rich project. VALOR is a big balloon that can carry about 400 kilos above the Venus surface.

VALOR would be the third balloon to visit the skies of Venus. In 1985, two comet-bound Soviet probes dropped off landers at Venus, each carrying an "aerostat" balloon probe designed by Soviet and French engineers. As the landers descended, they released their helium-filled balloons some 33 miles above the ground. The altitude was important, says balloon designer Jacques Blamont:

Venus ballooning is very easy above 50 kilometers [31 miles] altitude. It is more cool up there. At lower levels, it is still possible, but has not been done.

Each Teflon balloon spanned 11½ feet in diameter and carried a battery-powered instrument gondola to observe pressure, temperature, light levels, windspeeds, and mist density. The missions lasted until their batteries gave out, nearly 48 hours into each flight.