In recent years, we have grown used to seeing a stream of new pictures taken from the surface of Mars and the Moon from advanced landers and rovers on these worlds. Combined with images acquired decades ago by earlier missions (especially the half dozen manned Apollo landing missions, in the case of the Moon), we have been treated to a myriad of vistas from multiple sites across these worlds. Unfortunately, the same cannot be said about our nearest planetary neighbor, the cloud-shrouded Venus. Although most of the hidden surface of Venus has been mapped to a resolution as good as 120 meters using radar-equipped orbiters, we only have close up surface images from four sites across this geologically varied world owing to the harsh surface environment with an atmospheric pressure about 90 times that of the Earth with temperatures around 460° C.
While the first successful landing on Venus was made in December 1970 by the Soviet Venera 7 (see “Venera 7: The First Landing on Another Planet”), this lander and its successor, Venera 8 which reached Venus in July 1972 (see “Venera 8: The First Characterization of the Surface of Venus“), did not carry cameras because the glacial one-bit-per-second transmission rate could not support them. It was only after the introduction of the much larger and more capable 4V-1-series of Venera landers built by the NPO Lavochkin design bureau that cameras and other advanced instrumentation could be supported using the carrier spacecraft as a relay. The first images from the surface of Venus (or the surface of any planet, for that matter) were returned in October 1975 by the Venera 9 and 10 missions (see “Venera 9 and 10 to Venus”).
This is a processed version of the panorama returned by Venera 9 from the surface of Venus on October 22, 1975. It was created by Ted Stryk applying modern digital image processing techniques to the original data. Click on image to view the original source. (Russian Academy of Sciences/Ted Stryk)
This is a processed version of the panorama returned by Venera 10 from the surface of Venus on October 25, 1975. It was created by Ted Stryk applying modern digital image processing techniques to the original data. Click on image to view the original source. (Russian Academy of Sciences/Ted Stryk)
While Venera 9 and 10 successfully returned one view each from the surface of Venus, they actually each carried a pair of imagers with one on each side of the 660-kilogram landers. Unfortunately, the lens caps on the second imager on each lander failed to eject properly. The second pair of heavier 731-kilogram 4V-1 landers, Venera 11 and 12 which reached Venus in December 1978, also carried a pair of improved cameras each but this time both lens caps on both landers failed to be ejected resulting in the failure to return any images. The next opportunity to secure images from the surface of Venus had to wait for the arrival of the first pair of improved 4V-1M landers launched in the fall of 1981.
Here is a diagram of the Venera 13 and 14 landers. The call outs for the labelled components are 1) accelerometers, 2) nephelometer, 3) mass spectrometer, 4) gas chromatograph, 5) spectrometer & UV photometer, 6) telephotometers, 7) penetrometer, 8) X-ray flourescent spectrometer for aerosols, 9) X-ray flourescent spectrometer for soil, 10) drill & soil delivery device, 11) pressure and temperature instruments, 12) radio spectrometer, 13) hygrometer and 14) experimental solar cells to measure surface illumination. Click on image to enlarge.
The “cameras” carried by the 4V-1 landers were a pair of panoramic telephotometers mounted on opposite sides of the pressure vessel at a height of 0.9 meters above the ground. Similar in design to those carried by earlier Soviet Moon and Mars landers (as well as the cameras on NASA’s Viking landers, see “First Pictures: Viking 1 on Mars – July 20, 1976”), these telephotometers scanned one column of the scene at a time to build up a full 37° by 180° panorama. With the telephotometers canted 50° downward, they could scan from the foot of the lander out to the horizon on either side. Unlike the telephotometers carried by Venera 9 and 10, the units on the newer landers had four detectors fitted with clear, red, green and blue filters. By continuously rescanning the scene with each successive color filters, color panoramas could be produced. These telephotometers would create 1024-by-252-pixel images digitized to 9 bits – a significant improvement over the earlier imagers with their 512-by-128-pixel images digitized to 6 bits. Handling this 24-fold increase in imaging data was made possible with the introduction of the new Soviet 70-meter RT-70 radiotelescope located in Yevpatoria, Crimea. Using the lander’s carrier spacecraft as a relay during its distant flyby, the data rate from the surface of Venus increased from 256 to 3,000 bits per second.
A view of the 70-meter RT-70 radiotelescope in Yevpatoria, Crimea used to receive data from the Venera 13 and 14 missions. (S. Korotikiy)
The first of the improved 4V-1M landers, Venera 13, touched down on the surface of Venus at 03:57:21 UT on March 1, 1982. It landed at 7.55° S, 303.69° E on the rolling hills adjacent to Dolya Tessera east of Navka Planitia. Measurements after landing showed that the atmospheric pressure was 89.5 times that of Earth with a temperature of 465° C (although the interior of the lander was kept at a more comfortable 30° C). Immediately after landing, both telephotometers successfully ejected their covers and started scanning the scene. One of the telephotometers was programed to scan the entire 180° scene successively in clear, red, green and blue detectors – a process that would take almost an hour even with the improved data uplink. In order to return at least a fragment of full-color data in the nominal 30-minute design life of the lander, the other telephotometer was programmed to scan the entire 180° scene first through the clear filter followed by scanning just a 60° segment on the right side (where a 9-centimeter-wide color calibration target was deployed) through red, green and blue filters. Both telephotometers repeated this scanning pattern until contact was lost with its carrier passing 36,000 kilometers overhead.
A Soviet-processed version of the panorama returned by Camera 1 on Venera 13 on March 1, 1982. Note that only the right third, which was scanned using all four filters, is in color. Click on image to enlarge. (Don Mitchell).
A Soviet-processed version of the color panorama returned by Camera 2 on Venera 13. The ejected lens cap is visible near the center at the foot of the lander. Click on image to enlarge. (Don Mitchell)
After transmitting for a record 127 minutes from the surface of Venus (a record which stands to this day), Venera 13 managed to transmit a total of 11 full panoramas and 10 partial ones. The panoramas were combined to fill in gaps from missing data and create full color views. With the Sun 54° above the horizon (the equivalent solar time of 9:10 AM), about 2.5% of the Sun’s light reached the surface to give an overall orange to yellow appearance to the scene due to the lack of bluer wavelengths penetrating the dense atmosphere. The huge improvement in image quality compared to the earlier Venera 9 and 10 panoramas was apparent with objects as small as a fraction of a millimeter visible at the foot of the lander. The landing site, with rolling ridges visible in the distance, was dominated by flat, layered strata with small rocks and fine grain material eroded from the bedrock filling the hollows. The movement of small grains visible at the foot of the lander between successive scans of the telephotometers were consistent with a gentle (if not very refreshing) breeze with a speed of 0.3 to 0.6 meters per second. Venera 14 repeated this feat four days later landing 950 km southwest of its sister on March 5, 1982. Along with the panoramas returned during the 57-minute active life of Venera 14, these images remain the only color views with have of the surface of Venus even four decades later.
A Soviet-processed version of the panorama returned by Camera 1 on Venera 14 on March 5, 1982. Note that only the right third, which was scanned using all four filters, is in color. Click on image to enlarge. (Don Mitchell).
A Soviet-processed version of the color panorama returned by Camera 2 on Venera 14. Click on image to enlarge. (Don Mitchell)
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Related Reading
“Venera 9 and 10 to Venus”, Drew Ex Machina, October 22, 2015 [Post]
General References
Brian Harvey, Russian Planetary Exploration: History, Development and Prospects, Springer-Praxis, 2007
Wesley Huntress, Jr. and Mikhail Ya. Marov, Soviet Robots in the Solar System: Mission Technologies and Discoveries, Springer-Praxis, 2011
V. I. Moroz, “Summary of Preliminary Results of the Venera 13 and Venera 14 Missions”, in Venus (D.M. Hunten, L. Colin T.M. Donohue and V.I. Moroz, editors), pp. 45-68, University of Arizona Press, 1983
Paolo Ulivi with David M. Harland, Robotic Exploration of the Solar System Part 1: The Golden Age 1957-1982, Springer-Praxis, 2007
Andrew Wilson, Solar System Log, Jane’s Publishing, 1987