A European satellite set for launch tomorrow will provide a new level of data about our environment, the weatherand global warming, writes John Moore
The European Space Agency's largest Earth-monitoring satellite, Envisat, sits poised and ready for launch tomorrow from Kourou, in French Guiana. On board, 10 of the most sophisticated instruments ever assembled on one satellite will continuously observe Earth's land, sea, ice caps and atmosphere.
The satellite will provide an important new range of data on ozone fluctuations and global warming and is likely to have an impact on political decisions about environmental commitments such as the Kyoto Protocol.
Costing more than €2.3 billion, Envisat stands 10 metres tall and weighs eight tonnes. More than 100 companies were involved in the development, including the Dublin-based firm Devtec, which designed the mechanical supports for the Ariane 5 launcher's Vulcain 2 engine.
Envisat's suite of instruments will work as a group of satellites in one. "Most of the instruments are interactive," says Dr Jacques Louet, Envisat's programme manager. "When you look at one environmental phenomenon, most of the time, several variables are operating at once. The synergetic use of the instruments will be crucial here."
Irish scientists at the Coastal Resources Centre, which is based at University College Cork, will have a particular interest in data from Envisat's advanced synthetic aperture radar (ASAR) instrument. It will illuminate Earth's surface with a radar beam and use the reflected echoes to determine wave direction.
"We can improve applications for our coastal zones by utilising ASAR's data," says Valerie Cummins of University College Cork. Cummins is involved with the Marsais - Marine SAR Analysis and Interpretation System - project, which includes the Coastal Research Centre.
It is developing algorithms for examining sea-surface currents, oil slicks, algal blooms and coastal features. "From Envisat's data, we can then develop tools that will be used to help Irish port operators, oil companies, harbour authorities or people involved in aquaculture."
Met Éireann will also have an interest in what Envisat has to offer. "The data will definitely be of higher quality," says Kieran Commins. "We currently use the Meteosat, ERS-2 and NOAA [National Oceanic and Atmospheric Administration] satellites, and it will greatly help us with near-surface wind and wave data, as well as oil-spill and ship-traffic movements."
The appearance in orbit of Gomos, the technically advanced ozone instrument on Envisat, couldn't be more timely. It will measure ozone depletion over Europe amid signs that ozone loss is accelerating.
Early this month, the layer thinned considerably for several days over Europe. Data from ERS-2, another ESA satellite, detected finger-like appendages of thinned ozone, and the scientists aren't sure what caused them to appear. The Gomos instrument will help.
Envisat will also monitor Earth's temperature - expected to rise by between three and 10 degrees Fahrenheit this century - in greater detail. Greenhouse gases are blamed, carbon dioxide being the main culprit. As 6.5 billion tonnes are created yearly, an instrument called Sciamachy will map in three dimensions the migration of these gases at any altitude.
But it's not just the array of instruments that has scientists excited, it's the quantity and quality of data that will flow from Envisat. Every day, enough information will come in to fill the hard disks of hundreds of PCs assembled at the space agency's data-processing centre, near Rome. More than 700 projects have already been selected to use the data.
But will Envisat ever get off the ground? Its launch has been postponed several times. And, last July, an Ariane 5 rocket accidentally put the European Space Agency's Artemis satellite into a lower than planned orbit. Engineers studying the failure have yet to recreate the error that caused it.
The space agency is confident, however, that Envisat will fly and soon be providing important new data about the environment and our impact on it.
You can get up-to-date news on the mission from the European Space Agency's Envisat website, which is at http://envisat.esa.int