32 research outputs found
Study of the dynamic of the Venus atmosphere using the automatic interplanetary stations Venera-5 and Venera-6
Analysis of Venus atmosphere with automatic interplanetary station
Venera-11 and Venera 12: Preliminary estimates for the wind speed and turbulence in the atmosphere of Venus
The methods and results of measurements for wind speed and atmospheric turbulence in the clouds of Venus are described, and compared with earlier results. The distribution of wind speed obtained from the data of Venera 12 is in good conformity with the data of the preceding Venera and Pioneer probes, indicating the existence of a constant and powerful zonal movement of the troposphere
Vertical thermal structure of the Venus atmosphere from temperature and pressure measurements
Accurate temperature and pressure measurements were made on the Vega-2 lander during its entire descent. The temperature and pressure at the surface were 733 K and 89.3 bar, respectively. A strong temperature inversion was found in the upper troposphere. Several layers with differing static stability were visible in the atmospheric structure
Aerial Deployment and Inflation System for Mars Helium Balloons
A method is examined for safely deploying and inflating helium balloons for missions at Mars. The key for making it possible to deploy balloons that are light enough to be buoyant in the thin, Martian atmosphere is to mitigate the transient forces on the balloon that might tear it. A fully inflated Mars balloon has a diameter of 10 m, so it must be folded up for the trip to Mars, unfolded upon arrival, and then inflated with helium gas in the atmosphere. Safe entry into the Martian atmosphere requires the use of an aeroshell vehicle, which protects against severe heating and pressure loads associated with the hypersonic entry flight. Drag decelerates the aeroshell to supersonic speeds, then two parachutes deploy to slow the vehicle down to the needed safe speed of 25 to 35 m/s for balloon deployment. The parachute system descent dynamic pressure must be approximately 5 Pa or lower at an altitude of 4 km or more above the surface
Implications of Preliminary VEGA Balloon Results for the Venus Atmosphere Dynamics
The typical 1-2 m/sec vertical winds encountered by the Vega balloons probably result from thermal
convection. The consistent 6.5-kelvin differential between the Vega 1 and Vega 2 temperatures is attributable
to disturbances of synoptic or planetary scale. According to the Doppler tracking the winds were stronger
than on earlier missions, perhaps because of solar thermal tides. The motions of Vega 2 may have been
affected by waves from mountainous terrain
Thermal structure in the Venus middle cloud layer
Thermal structure measurements obtained by the two Vega balloons show the Venus atmosphere in the middle cloud layer to be near-adiabatic, on the whole; but discrete air masses are present that differ slightly from one another in potential temperature and entropy. The Vega 1 temperatures are 6.5 K warmer than measured by Vega 2 at given pressures. Measurements taken by the Vega 2 lander on descent through these levels agree with the Vega 2 balloon data
Meteorological Data Along the VEGA-1 and VEGA-2 Float Paths
During their flight through the Venus atmosphere
the Vega 1 and Vega 2 balloon craft measured
the pressure and temperature of the ambient
medium, the vertical wind-velocity component (relative
to the gondola), the cloud-layer backscatter
coefficient, the mean illumination level, and the number
and time of possible lightning flashes. In addition, the ground radio telescope network measured
the balloon positions and drift velocities by the differential
VLBI technique; these data are now being
processed