Marcello Coradini is coordinator of solar science missions at the European Space Agency (ESA) and a veteran of Europe’s growing space programme. Making the distinction between planetary and solar missions he said “Studying the sun has a strong input from astrophysicists and astronomers, whereas planetary exploration has a definite geological emphasis, and these groups have different cultures”. He also reminded the audience that Europe has national space agencies and efforts in addition to ESA – which adds more to the cultural mix. Coradini then gave a brief history of famous European satellites, starting with those aimed at our own sun.
|The Earth & Space Expo|
Up and over the sun
Ulysses was ESA’s first satellite launched to study the sun and it notched up a number of other ‘firsts’ recalled Coradini. It was the first satellite to use gravitational assistance, whereby a satellite is swung close around a planet to gain energy from the gravitational field and is then slung out the other side. Ulysses swung around Jupiter to gain energy and was then thrown out of the ecliptic plane, approaching the sun from above (another first) – this positioning was critical to its mission: to study the sun’s polar regions and observe the geomagnetic field for the first time. Ulysses was followed by the SOHO satellite, launched with NASA but with a Made in Europe sticker. As Coradini explained, “At the time, SOHO was the largest satellite ever launched and provided many of the images of the sun’s surface that we still see around us today. Because SOHO was positioned to view the sun continuousl, it also provided the first opportunities for solar weather forecasts. Storms on the sun can displace satellites in earth orbit, degrade communications systems and cause problems to heart patients’ pace-makers – so this was a new and very useful capability.”
Returning to planetary exploration, Coradini described the highlights of recent and upcoming missions including: Venus Express, a Mars Express lookalike that will launch in 2005 to study the Venusian atmosphere; and BepiColombo, a joint mission with the Japanese Space Agency to map and measure Mercury, unlocking clues to planetary formation mechanisms from orbit. Still in development, BepiColombo will be a two-spacecraft mission that will use the latest solar-electric (ion) propulsion technology, first tested in ESA’s current SMART-1 moon mission.
On the running Cassini-Huygens mission, that brings new insights every day, Marcello Coradini reminded the audience of the historic nature of this mission, “Titan is the first new world Europe has landed on since discovering America, and Titan’s primeval atmosphere allows us to look back over one billion years into Earth’s own past.” He went on to stress the importance of investigating the origins of planetary atmospheres if we want to understand our own – as Europe is doing with Cassini-Huygens, Mars Express and Venus Express.
Ever greater challenges
After entertaining the audience with exploration results from the rings and moons of Saturn and from Mars, Marcello Coradini returned to his theme of links with the past when describing the Rosetta mission; “The famous Rosetta Stone allowed us to use language to link with past civilizations. In a similar way the Rosetta mission, which is now underway, will allow us a glimpse of the original chemistry of the solar system from over 4 billion years in the past.” Rosetta carries the Philae module that will land on the surface of the comet Churyumov-Gerasimenko in 2014 and spend two years taking a piggyback ride around the solar system while analyzing the comet’s properties – it is one of the most technically challenging missions ever.