Vega At Venus Options

[Paolo]

I have an AWST article that says that the Vega buses were occulted by Venus and performed radioccultation experiments. However, no results were apparently ever published and the occultation is not mentioned anywhere else. Anybody knows anything more?

[bobik]

A 2012 review article on the VEGA project states the following about the Vega-1 event:

During the descent of the landers in the atmosphere, from the point of the release of the lower hemisphere and until the landing, measurements were made of the atmospheric temperature and pressure as well as the angular velocity of rotation of the vehicle about the three axes. The curves of the atmospheric temperature and pressure during the descent of the Vega 1 and 2 landers are well consistent with, and almost similar to, the calculated curves, which confirms the validity of the computational model of the atmosphere. ... The maximum spin rates around the longitudinal axis during the parachute descent were 64 and 24 deg/s and those around the transverse axis were 60 and 30 deg/s, respectively; during the descent with drag devices, the longitudinal rates did not exceed 25 and 15 deg/s and the transverse rates did not exceed 60 and 35 deg/s. During the descent of the Vega 1 lander, at an altitude of about 17 km above the planet’s surface, the landing signaling device, a shock sensor set for 6 ± 1.5 units overload, was activated. The altitude region from 10 to 20 km is characterized by the maximum gradient of the horizontal wind component, which must be accompanied by a considerable turbulence of the vertical wind component. Calculations suggest that the premature activation of the signaling device of the Vega 1 lander could have been caused by a sudden vortex flow with a velocity of more than 30 m/s.

So in this version of the story, the gust which hit the Vega-1 lander had a velocity of about 30 m/s, but not, as Kerzhanovich indicated, the lander itself was "flung back upward at seventy miles an hour". By the way, wouldn't a gamma-ray densitometer be a reliable instrument for the indication of touchdown?