Determination of Venus Winds by Ground-Based Radio Tracking of the VEGA Balloons

Abstract

A global array of 20 radio observatories was used to measure the three-dimensional position and velocity of the two meteorological balloons that were injected into the equatorial region of the Venus atmosphere near Venus midnight by the VEGA spacecraft on 11 and 15 June 1985. Initial analysis of only radial velocities indicates that each balloon was blown westward about 11,500 kilometers (8,000 kilometers on the night side) by zonal winds with a mean speed of about 70 meters per second. Excursions of the data from a model of constant zonal velocity were generally less than 3 meters per second; however, a much larger variation was evident near the end of the flight of the second balloon. Consistent systematic trends in the residuals for both balloons indicate the possibility of a solar-fixed atmospheric feature. Rapid variations in balloon velocity were often detected within a single transmission (330 seconds); however, they may represent not only atmospheric motions but also self-induced aerodynamic motions of the balloon.

Six years of Venus winds at the upper cloud level from UV, visible and near infrared observations from VIRTIS on Venus Express

“…This global trend was derived by Ignatiev et al (2009) from VIRTIS-M spectroscopy and VMC images and was later confirmed by Lee et al (2012) by joint analysis of the VeRa and VIRTIS instruments on Venus Express. A recent detailed work based on VIRTIS data confirms this trend (Haus et al, 2014) which is also in agreement with earlier radiative transfer results (Zasova et al, 2007) and in situ measurements during the descent of the Venera and Pioneer Venus probes (Schubert, 1983) and from tracking of VEGA balloons (Preston et al, 1986).…”

Overview of the coordinated ground‐based observations of Titan during the Huygens mission

“…VLBI tracking of planetary spacecraft for navigation was developed in the mid‐1970s and has been frequently used since then [ Thornton and Border , 2003]. VLBI observations of planetary probes have also been used to measure lunar rotational dynamics [ King et al , 1976; Slade et al , 1977] and winds on Venus [ Counselman et al , 1979; Preston et al , 1986; Sagdeyev et al , 1992]. We note that the VLBI technique offers extremely high angular resolution that is inversely proportional to the baseline (distance) between the telescopes involved.…”

Infrasound and Gravity Waves Over the Andes Observed by a Pressure Sensor on Board a Stratospheric Balloon

“…The Venus ground atmospheric conditions (9e 6 Pa and 700 K) do not allow any long‐duration deployment on the surface, even modern technology cannot withstand these temperatures and pressures for more than a couple of hours. In contrast, balloons with infrasound sensors would overpass these limitations and may be able to probe the interior structure of a planet by acoustic pulses from seismic activity on its surface (Garcia et al, ) and its atmosphere structure and dynamics (Preston et al, ).…”