Venera 4
Published on Jun 12, 2008 at 4:46 pm.
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Filed under history, space exploration.
41 years ago, on June 12, 1967, a modified R-7 rocket lifted off from deep within the Soviet Union carrying a spacecraft to another world. The spacecraft was Venera 4, and it was on its way to Venus. Venera 4 was not the first spacecraft to arrive at Venus. That honor goes to the American Mariner 2 spacecraft, launched in 1962. But, Mariner 2 just flew by Venus. Venera 4 was destined to actually enter the planet’s atmosphere.
As the name implies, Venera 4 was not the first spacecraft that the Soviet Union sent to Venus. However, it was the first one to work as expected. Contact with Veneras 1 and 2 was lost as they were en route. Venera 3 had arrived, but contact was lost before it entered the atmosphere, so it sent back no data from the most important part of its mission. Soviet scientists knew that these first spacecraft to Venus had no chance of landing, but the goal was to enter the atmosphere and send back as much data as possible before the spacecraft was destroyed.
Venera 4 worked nearly flawlessly, making it the first spacecraft to perform in situ studies of another planet’s atmosphere. On October 18, 1967, after four months traveling through space from Earth to Venus, the Venera 4 atmospheric probe made its dive into the atmosphere. It deployed a parachute to slow its descent. It then used thermometers, a barometer, and gas analyzers to monitor the atmosphere as it descended. Contact was finally lost at an altitude of about 25 kilometer. The pressure and temperature on Venus are fatal to most spacecraft, and Venera 4 undoubtedly was crushed long before making it to the surface of the planet (though the first reports released by the Soviet Union had claimed that the craft had actually landed intact on the surface of the planet). Even if it had not been crushed, the heat would have destroyed the electronic circuitry of the craft.
Interestingly, Venera 4 wasn’t alone in its trip to Venus. Launched two days later, America’s Mariner 5 spacecraft also was on its way to Venus, flying by on October 19, one day after Venera 4 had arrived.
Today, with the amazing images coming back from Phoenix and the other successful space missions, we tend to overlook these important first steps in planetary exploration. But, without spacecraft like the early Venera series or the Mariners, we wouldn’t be where we are today in planetary exploration.
-Astroprof
Image Credit: NASA, NSSDC
