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Venera 2
| title |
Venera 2 |
| date |
11.12.1965 |
| description |
Although the 3MV-3 and 3MV-4 type spacecraft were originally intended for Mars exploration, the Soviets re-equipped three of the series, left over from the 1964 Mars launch windows, for Venus exploration in 1965. This particular vehicle was scheduled to fly past the sunlit side of Venus at no more than a 40,000-kilometer range and take photographs. During the outbound flight, communications with the spacecraft were poor. Immediately before closest approach in late February 1966, ground control commanded to switch on all the onboard scientific instrumentation. o The closest approach to the planet was at 02:52 UT on 27 February 1966 at about a 24,000-kilometer range. After its flyby, when the spacecraft was supposed to relay back the collected information, ground control was unable to regain contact. Controllers finally gave up all attempts at communication on 4 March. Venera 2 eventually entered heliocentric orbit. Later investigation indicated that improper functioning of 40 thermal radiator elements caused a sharp increase in gas temperatures in the spacecraft. As a result, elements of the receiving and decoding units failed, the solar panels overheated, and contact was lost. Ironically, the scientific instruments may have collected valuable data, but none of it was ever transmitted back to Earth."Editor's Note: This mission profile was originally published in *Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000*, by Asif A. Siddiqi, NASA Monographs in Aerospace History No. 24" |
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Venera 9
| title |
Venera 9 |
| date |
06.08.1975 |
| description |
Venera 9 was the first of a new generation of Soviet space probes ('4V') designed to explore Venus. Launched by the more powerful Proton launch booster, the new spacecraft were nearly five times heavier than their predecessors. Each spacecraft comprised both an orbiter and a lander. The 2,300-kilogram orbiters (at Venus orbit insertion) were designed to spend their missions photographing the planet in ultraviolet light and conducting other scientific investigations. The landers, of a completely new design, employed aerodynamic braking during Venusian atmospheric entry and contained a panoramic photometer to take images of the surface. Without any apparent problems and with two trajectory corrections (on 16 June and 15 October), Venera 9's lander separated from its parent on 20 October 1975, and two days later, it hit Venus's turbulent atmosphere at a speed of 10.7 kilometers per hour. After using a series of parachutes, the lander set down on the planet's day side at 05:13 UT on 22 October. Landing coordinates were 32° north latitude and 291° longitude at the base of a hill near Beta Regio. During its 53 minutes of transmissions from the surface, Venera 9 took and transmitted the very first picture of the Venusian surface from a height of 90 centimeters. These were, in fact, the very first photos received of the surface of another planet. The lander was supposed to transmit a full 360° panorama, but because one of the two covers on the camera failed to release, only a 180° panorama was received. Illumination was akin to that of a cloudy day on Earth. The image clearly showed flat rocks strewn around the lander. The Venera 9 orbiter meanwhile entered a 1,500 x 111,700-kilometer orbit around the planet at 34°10' inclination and acted as a communications relay for the lander. It became the first spacecraft to go into orbit around Venus. The Soviets announced on 22 March 1976 that the orbiter's primary mission, which included using French-made ultraviolet cameras to obtain photographs in 1,200- kilometer swaths, had been fulfilled. |
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The Surface of Venus from th
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| title |
The Surface of Venus from the Venera 10 Lander |
| date |
10.25.1975 |
| description |
Venera 10 Lander image of the surface of Venus at about 16 N, 291 E. The Lander touched down at 5:17 UT on 25 October 1975 and returned this image during the 65 minutes of operation on the surface. The sun was near zenith during this time, the lighting was about what would be seen on Earth on an overcast summer day. The objects at the bottom of the image are parts of the spacecraft. The image shows flat slabs of rock, partly covered by fine-grained material, not unlike a volcanic area on Earth. The large slab in the foreground extends over 2 meters across. Automatic gain control and logarithmic quantization were used to handle the unknown dynamic range of illumination. The raw image was converted to optical density according to Russian calibration data, then to linear radiance for image processing. It was interpolated with windowed sinc filter to avoid post-aliasing (a "pixilated" appearance), and the modulation transfer function ("aperture") of the camera was corrected with a 1 + 0.2*frequency**2 emphasis. This was then written out as 8-bit gamma-corrected values, using the sRGB standard gamma of 2.2. The bottom image is a digitally in-painted version, using Bertalmio's isophote-flow algorithm. (Venera 10 Lander, processed surface image) (Image posted with permission, copyright 2003 Don P. Mitchell. All rights reserved.) *Image Credit*: NASA |
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Venera 3
| title |
Venera 3 |
| date |
11.06.1965 |
| description |
This was the second of three 3MV spacecraft the Soviets attempted to launch toward Venus in late 1965. Venera 3 successfully left Earth orbit and released a small 0.9- meter-diameter, 337-kilogram (some sources say 310-kilogram) landing capsule to explore the Venusian atmosphere and transmit data on pressure, temperature, and composition of the Venusian atmosphere back to Earth during the descent by parachute. During the outbound trajectory, ground controllers successfully performed a midcourse correction on 26 December 1965 and completed 93 communications sessions. However, contact was lost on 16 February 1966, shortly before the Venusian encounter, although the spacecraft automatically released its sterilized lander probe, which landed inertly on the Venusian surface at 06:56 UT on 1 March 1966. It was the first time a humanmade object had made physical contact with another planetary body besides the Moon. Later investigation confirmed that Venera 3 suffered many of the same failures as Venera 2, such as overheating of internal components and the solar panels. |
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