On Tuesday, at the end of a 153-day and 400-million km cruise into the inner
solar system beginning with its launch on 9 November 2005, ESA's Venus
Express space probe fired its main engine at 09:17 CEST for a 50-minute
burn, which brought it into orbit around Venus. With this firing, the probe
reduced its relative velocity toward the planet from 29,000 to about 25,000
km/h and was captured by its gravity field. This orbit insertion manoeuvre
was a complete success.

During the next four weeks, the Venus Express probe will perform a series of
manoeuvres to reach the scheduled operational orbit for its scientific
mission. It will move from its current highly elongated 9-day orbit to a
24-hour polar orbit, culminating at 66,000 km. From this vantage point, the
orbiter will conduct an in-depth observation of the structure, chemistry and
dynamics of the atmosphere of Venus for at least two Venusian days (486
Earth days).
Enigmatic atmosphere

From previous missions to Venus as well as observations directly from Earth,
we already know that our neighbouring planet is shrouded in a thick
atmosphere where extremes of temperature and pressure conditions are common.
This atmosphere creates a greenhouse effect of tremendous proportions as it
spins around the planet in four days in an unexplained "super-rotation"
phenomenon.

The mission of Venus Express will be to carry out a detailed
characterisation of this atmosphere, using state-of-the-art sensors in order
to answer the questions and solve the mysteries left behind by the first
wave of explorers. It will also be the first Venus orbiter to conduct
optical observations of the surface through "visibility windows" discovered
in the infrared spectrum.V The commissioning of the onboard scientific
instruments will begin shortly and the first raw data are expected within
days. The overall science payload is planned to be fully operational within
two months.

(much more at http://www.southgatearc.org/news/apr...enus_orbit.htm )