Tuesday, October 18, 2005

UK scientists lead mission to Venus - Scotsman


UK scientists lead mission to Venus

EUROPEAN scientists will this month attempt the first trip to the planet Venus for 15 years.
In a pre-launch briefing yesterday, the European Space Agency laid out its hopes for the £150 million, unmanned mission to Earth's nearest neighbour.

The mission - Venus Express - is due to embark on its five-month journey on 26 October and scientists hope it will offer clues into how the Earth will respond to increasing greenhouse gases.
Venus, easily identifiable from Earth as the morning star, is similar in size and mass to our planet and, in relative terms in the solar system, a similar distance to the Sun.
However, Venus has 100 times the atmospheric pressure of Earth; its atmosphere is a dense cloud of carbon dioxide released through its constant volcanic activity.
Carbon dioxide and other greenhouse gases insulate the planet, heating the surface to an average temperature of 450C.
Sulphuric acid routinely rains on to a barren terrain of deserts and lava-coated mountains, and scientists believe the planet provides a stark lesson on the effects of runaway global warming.
Dr Andrew Coates, from University College London's Mullard Space Science Laboratory in Dorking, Surrey, is one of several British scientists involved in the mission. He said: "Venus is sometimes called Earth's 'evil twin' - it has some similarities like size, but big differences like hotter-than-oven temperatures, sulphuric acid clouds, crushing surface pressure, rotation the 'wrong' way around its axis - and no protective magnetic field.
"Venus Express will look at how the planet's thick atmosphere works, and how it interacts with the surface below and escapes to space above. Studying Venus, especially the runaway greenhouse effect, may give us vital lessons for the Earth's future."
The mission will orbit the planet in April 2006 and study the mysterious hurricane-like vortices above the poles. From the spacecraft, scientists will also be able to look for signs of volcanic activity.
Clues may be found from sulphuric acid and sulphur dioxide in the lower atmosphere, and shock waves sent through the clouds by the violent tremors and quakes on the surface.
A number of British institutions and companies have contributed to Venus Express. Scientists from the Rutherford Appleton Laboratory and UCL's Mullard Space Science Laboratory in Dorking, are co-investigators for an instrument called Aspera which will probe molecules and energetic particles in the atmosphere.
Experts from Imperial College London are to analyse data from Mag, the spacecraft's magnetometer, which will measure the planet's atmospheric magnetic field.
The Stevenage-based company EADS Astrium built the propulsion system which will put the spacecraft in orbit, while SciSys, from Wiltshire, provided mission control systems.
Professor Colin Pillinger, the lead scientist for the failed Beagle 2 mission to Mars in December 2003, said details of Venus's hostile conditions might help people understand the implications of extreme amounts of greenhouse gas in the atmosphere.
"Of course, on Earth we are concerned because of carbon dioxide emissions from fossil fuels. Enormous amounts of carbon dioxide in the atmosphere might turn our planet into something like Venus. So we need to understand what's happening there."
Venus Express will be blasted into space by a Russian Soyuz-Fregat rocket launched from the Baikonur cosmodrome in Kazakhstan. The same launch vehicle was used to send Mars Express on its way to the Red Planet.
In the 1970s and early 1980s, spacecraft launched by the former Soviet Union led the way in Venus exploration.
After a number of early failures, during which three spacecraft were crushed by the planet's atmospheric pressure, the USSR landed a series of Venera probes on Venus.
The probes were fitted with diamond windows to withstand the high atmospheric pressure and temperature.
The last dedicated mission to Venus was Magellan, launched by the American space agency NASA in 1990, which mapped the surface using radar.


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