Venus express: Highlights of the nominal mission

Abstract

-Venus Express is the first European (ESA) mission to the planet Venus. Its main science goal is to carry out a global survey of the atmosphere, the plasma environment, and the surface of Venus from orbit. The payload consists of seven experiments. It includes a powerful suite of remote sensing imagers and spectrometers, instruments for in-situ investigation of the circumplanetary plasma and magnetic field, and a radio science experiment. The spacecraft, based on the Mars Express bus modified for the conditions at Venus, provides a versatile platform for nadir and limb observations as well as solar, stellar, and radio occultations. In April 2006 Venus Express was inserted in an elliptical polar orbit around Venus, with a pericentre height of ~250 km and apocentre distance of ~66000 km and an orbital period of 24 hours. orbit. In particular, fundamental problems in the fields of atmospheric structure and composition, morphology and distribution of clouds and hazes, atmospheric dynamics, properties of plasma and magnetic field, and escape processes, are all addressed by the Venus Express observations. These investigations will shed light on the current climate of Venus, will make it possible to reconstruct the evolutionary path of our sister planet, and will make significant contribution to the field of comparative planetology.The Venus Express payload consists to a great extent of the instruments inherited from the Mars Express and Rosetta missions, which were found to be quite suitable for making a breakthrough in Venus studies (Titov et al., 2001). The payload core consists of a suite of imagers and spectrometers, combining wide spectral range from the UV to the thermal IR. Broad band context imaging and high spectral resolution makes the mission payload the most capable remote sensing package ever flown to Venus. This suite is complemented by a radio science experiment to investigate the structure of the neutral atmosphere and ionosphere. Two experiments monitor the ambient magnetic field and study the plasma environment and escape processes.

Atmospheric thermal structure and cloud features in the southern hemisphere of Venus as retrieved from VIRTIS/VEX radiation measurements

“…Real dipole features were seen very rarely during the VEX mission, however (Limaye et al, 2009). Luz et al (2011) andTitov et al (2009) also showed polar eye morphologies quite different from a dipole. Figure 8).…”

Thermal structure of Venusian nighttime mesosphere as observed by VIRTIS‐Venus Express

“…The Venus Express mission carries a variety of experiments suitable for the study of Venus temperature fields [ Titov et al , 2009; Drossart et al , 2007]. In this context, the mapping IR channel of the Visual and Infrared Thermal Imaging Spectrometer (VIRTIS) is particularly interesting for its capability to return synoptic maps of temperatures in the indicative range 65–95 km [ Grassi et al , 2008].…”

Spectroscopy from Space

“…Venus has a thick highly scattering atmosphere, making it the most difficult surface to be detected from space (excluding Jupiter, Saturn, Uranus, and Neptune whose surfaces, if they exist are impossible to see with UV to far infrared light). Three spacecraft have detected thermal emission from the surface using near-infrared wavelengths: Galileo NIMS (Carlson et al 1991), Cassini VIMS (Baines et al 2000), and Venus Express VIRTIS (Müller et al 2008, Titov et al 2009 and references therein). Baines et al 2000showed that it could be possible to use a few windows in the Venetian spectrum to detect broad electronic absorptions due to iron in surface minerals and Hashimoto et al (2008) have used these windows and suggested felsic materials in Venus's highlands.…”