Venera 9

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Venera 9
NSSDC ID 1975-050
Mission goal Investigation of the planet Venus
Client USSR
Launcher Proton K
construction
Takeoff mass 4936 kg
Instruments

Spectrometer, photometer, radiometer, polarimeter, radar, proton, alpha, electron detectors

Course of the mission
Start date June 8th 1975
launch pad Baikonur ramp 81
End date December 25, 1975
 
 June 8, 1975 Start from Baikonur
 
 10/20/1975 Orbiter and lander separate
 
 10/22/1975 Orbiter enters Venus orbit
 
 10/22/1975 Landing of the lander
 
 December 25, 1975 Last contact with Orbiter
Artist's impression of the landed Venera 9 probe.
Photo of the surface of Venus taken by Venera 9

Venera 9 ( Russian Венера-9 ) was a space probe of the USSR to explore the planet Venus . It was launched on June 8, 1975 at 02:38:00 UTC from the Baikonur Cosmodrome with a Proton rocket, consisted of an orbiter and a lander and weighed 4,936 kg. The orbiter was the first spacecraft to enter an orbit around Venus; the lander transmitted the first images from the surface of another planet. Its identical sister probe Venera 10 followed six days later.

Venera 9 and 10 were the first probes of the second generation of Soviet Venus probes, which with their launch weight of almost five tons made possible by the new Proton rockets exceeded all previous Venus missions many times over in payload.

Landing probe

Since the conditions on the ground were known through the Venera missions , the USSR began in 1974 to construct Venus landing probes that were not only supposed to provide atmospheric data, but could also carry out investigations on the ground.

descent

The Venera 9 lander, housed in a 2.5 m ball during the flight, separated from the orbiter on October 20, 1975 and entered the Venusian atmosphere at a relative speed of 10.7 km / s. The descent was divided into the following phases:

  • Atmospheric braking up to an altitude of 65 km and a speed of 250 m / s
  • Parachute braking up to a speed of 150 m / s
  • More parachutes opened, the transmitters were activated and transmitted data
  • The three main parachutes with an area of ​​180 m² opened at a height of 62 km.
  • The three main parachutes were dropped at a height of 50 km, the lander was in free fall, the speed increased again until it decreased again due to the denser atmosphere
  • At 05.13 UTC the lander hit the surface of Venus with a residual velocity of 7 m / s. The rest of the energy was collected by a "crumple system".

Work on the surface of Venus

For the first time, a coarse-resolution panorama image was sent to earth. This was the first image from the surface of an alien planet, just a year before the Mars images from the Viking probes . Further instruments were a gas chromatograph for examining the atmosphere, a sample collector and drill for examining the physical structure of the surface. A seismometer also worked, but did not provide any data in the short time. Before landing, the equipment department had been cooled to −10 degrees Celsius, so Venera 9 worked 53 minutes longer than any previous space probe on the planet.

Orbiter

For the first time a planetary orbiter of the USSR was used. Shortly after separating from the lander, the orbiter made a course correction. At the closest approach to Venus, on October 22, 1975, the thrusters were fired again, so that the orbiter swung into an orbit of 1510 × 112,200 km, with an orbital time of approx. 48 hours. The orbiter itself transmitted images of Venus that are comparable in detail with those of Mariner 6 and 7. Other instruments were an 8–30 µm radiometer for temperature measurement and a 350 nm ultraviolet photometer from the CNES . A second VIS photometer / polarimeter measured between 400 and 700 nm. There was also a 1.5–3 µm infrared spectrometer, a magnetometer and an ion trap. The orbiter weighed 2300 kg empty.

Individual evidence

  1. ↑ a b c Venera 9 and 10. russianspaceweb.com, June 7, 2010, accessed on November 28, 2010 (English).
  2. ^ A b c Robert Reeves, The Superpower Space Race , ISBN 978-0306447686