ESA PR 13-2006. This morning, 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 kilometres. 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 prior 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.

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.

Europe explores the Solar System
With this latest success, ESA is adding another celestial body to its range of Solar System studies. ESA also operates Mars Express around Mars, SMART-1 around the Moon and is NASA's partner on the Cassini orbiter around Saturn. In addition, ESA is also operating the Rosetta probe en route to comet 67P/Churyumov-Gerasimenko. It should reach its target and become the first spacecraft ever to enter orbit around a comet nucleus by 2014. Meanwhile, ESA also plans to complete the survey of our celestial neighbours with the launch of the BepiColombo mission to Mercury in 2013.

"With the arrival of Venus Express, ESA is the only space agency to have science operations under way around four planets: Venus, the Moon, Mars and Saturn" underlines Professor David Southwood, the Director of ESA's science programmes. "We are really proud to deliver such a capability to the international science community".

"To better understand our own planet, we need to explore other worlds in particular those with an atmosphere," said Jean-Jacques Dordain, ESA Director General. "We've been on Titan and we already are around Mars. By observing Venus and its complex atmospheric system, we will be able to better understand the mechanisms that steers the evolution of a large planetary atmosphere and the change of climates. In the end, it will help us to get better models of what is actually going on in our own atmosphere, for the benefit of all Earth citizens."



Posted by: Edwin    Source