Rocketing Away - at a Price: Helen Gavaghan on How Europe's Newest Satellite Can Help Ensure That Environmental Treaties Stick. (Space)

Article excerpt

The night before the European Space Agency (ESA) successfully Launched its newest Earth-observing satellite -- Envisat -- earlier this year, gusting winds and driving rain created a gothic backdrop to a technological drama unfolding on the launch-pad.

At stake was the fate not only of around 2.3bn euros' worth of hardware (roughly [pounds sterling]1.4bn), but also of Europe's attempt to assert its technological independence from the United States and to carve a global leadership role for itself in the area of environmental sustainability.

The drama started when ventilation to the second stage of the rocket failed. With less than 24 hours to lift off, the launch team from the rocket company, Arianespace, began the five-hour task of disconnecting the launcher from the tower so that it could be wheeled back to the final assembly building for last-minute repairs.

Somehow, during the disconnection, a duct supplying air-conditioning to the satellite came loose. At a stroke, 40 per cent of the cooling was lost, creating the danger that the upper temperature limit of vital electronics on the satellite might be exceeded.

No sooner had the ESA's satellite team registered the problem than the remote camera that was monitoring operations at the launch-pad failed. "We had the satellite telemetry [remote reading of temperature, etc, around the satellite]," says Gilles Labruyere, principal structures and mechanisms engineer for Envisat, "so the blowwas more psychological than technically threatening." Nevertheless, the camera's loss blindsided the ESA's team which -- while Arianespace engineers worked on the rocket -- had begun monitoring telemetry, calculating all possible problems and devising contingencies.

Nor was Envisat clear of danger when it eventually reached orbit. If its solar panels had not unfurled, its batteries would have gone flat. The satellite, the product of 12 years of hardware and software development by a consortium of 50 companies led by Astrium, would have been rendered useless.

In the event, all ended well, with a successful launch on 1 March. But the drama showed why space agencies have switched from the development of big, multi-task satellites like Envisat to smaller spacecraft costing a great deal less. For example, the ESA is now at work on a satellite -- Cryosat -- which is to be launched in 2004 to monitor polar ice thickness.

Nevertheless, Envisat's all-singing, all-dancing suite of instruments gives the EU a chance of taking a leading role in environmental sustainability, using a strategy known as global monitoring for environment and security (GMES).

The idea is to establish by 2008 a global network of space-based, airborne and ground-based instruments that would monitor Earth's atmosphere, oceans, land and cryosphere (all the icy bits). The information will help policy-makers negotiate treaties to protect the environment and monitor compliance with them.

The satellite was conceived long before GMES was a glint in anyone's eye, purely as a means of enhancing our understanding of how changes in one part of Earth's system (warming of the atmosphere, say) impact on another (melting of the cryosphere). But as environmental concerns rose further up mainstream political agendas, the ESA and the EU began to see its uses in promoting environmental sustainability. …