Mariner 10 near Venus

Press, Volume CXIV, Issue 33452, 6 February 1974, Page 12

Mariner 10 near Venus

CN.Z. Press Association—Copyright) PASADENA (California), February 5. With 107 million troubled miles behind it, Mariner 10 has accelerated to its top speed to begin televising Venus as it swings around the cloudwrapped planet and flies on towards Mercury.

The first picture of what it is hoped will be a 17-day photographic mission is due to be received at the Jet Propulsion Laboratory in Pasadena early on Wednesday (New Zealand time). The spacecraft should beam about 1200 pictures to Earth, beginning from its closest approach to Venus, 3600 miles. Under the pull of Venusian gravity, the 11081 b craft will accelerate to 24.658 miles an hour at the point of closest approach. As it passes that point, the planet’s gravity will begin to drag on it, slowing it down so that the gravitation of the Sun can bend its flight path inwards to intercept Mercury. The plans call for Mariner 10 to transmit back to Earth 3712 pictures of Venus in all from its two cameras—one with a wide-angle lens, the other for close-ups—over the next 16 days, as it speeds away. It is also equipped to test the Venusian atmosphere with infra-red, ultra-violet, radio, plasma, and magnetic instruments. Because of its thick cloud cover. Venus was once thought to have a steamy, humid climate like that of I Earth’s tropical rain forests,! but radio astronomers and: Russian and American robot, space-explorers have estab-I lished that the Venusian! atmosphere is far too hot,; and under too great pressure, j for the planet to have any resemblance to Earth, or to support life. The atmsphere is apparently mostly carbon dioxide, with pressures up to 90 times that of Earth, and temperatures up to 900 degrees Fahrenheit. Mariner 10 has been afflicted by a series of minor problems. including the failure of

jits camera heaters —which ,1 later recovered as mysteriously as they had failed, an ! unexplained switch to the back-up power system, and a faulty camera-scan platform. Mariner 10 is supposed to dive to within 621 miles of Mercury on March 29, but without those adjustments, it will miss the planet by about 15,000 miles.