Mariner 2, shown here in an artist's concept, became the first spacecraft to successfully visit another planet when it flew less than 22,000 miles from Venus on December 14, 1962. The craft discovered that the cloud-covered surface of Venus is extremely hot. It also helped measure the length of a Venusian day, and while traveling toward the planet it detected the solar wind. [NASA]
NEUGEBAUER: It was just a hair-raising mission. Several things failed and then just recovered by themselves. It took about three miracles to get Mariner 2 to Venus. It just looked like the end several times along the way.
Fifty years ago, Marcia Neugebauer oversaw one of the experiments for the first successful mission to another planet. Mariner 2 flew less than 22,000 miles from Venus on December 14th, 1962.
In those early days of rocketry, missions failed as often as they succeeded. In fact, a twin Venus spacecraft, Mariner 1, had to be blown up less than five minutes after launch. And the United States still hadn’t even reached the Moon.
Mariner 2 was problem-plagued almost from the moment of launch. A sensor had a hard time tracking Earth, one of its solar panels failed, and it overheated. Yet even before it reached Venus, Mariner 2 was making important discoveries.
It resolved a dispute, for example, about the solar wind. Most physicists expected to find some sort of flow of charged particles from the surface of the Sun. But there was a major disagreement about the form of that flow. One leading scientist expected a million-mile-an-hour gale. But another expected more of a gentle breeze.
Within weeks, Mariner 2 resolved the issue — it discovered a high-speed solar wind that never let up during the long cruise to Venus.
But Mariner 2 is best known for transforming our concepts of Venus itself. More about that tomorrow.
Script by Damond Benningfield, Copyright 2012
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