ESA gives go ahead for satalite that can measure forests weight

The spacecraft will carry a novel radar system that is able to sense the trunks and big branches of trees from orbit.

Scientists will use Biomass to calculate the amount of carbon stored in the world's forests, and to monitor for any changes over the course of the five-year mission.

The satellite's data should help researchers understand better the role trees play in the cycling of carbon on Earth and, by extension, the influence this has on the planet's climate.

"Biomass will give us unprecedented knowledge on the state of the world's forests and how they are changing," said Prof Shaun Quegan, who was one of the key proposers of the mission. 

Biomass will be a 1.2-tonne satellite at launch, meaning it will probably go up on Esa's new Vega rocket, which successfully conducted only its second flight overnight.

Its sole instrument will send down a 70cm radar pulse that will penetrate the leafy canopies of forests but scatter back off the large woody parts of trees. It will sense the volume of material at a resolution of about 200m. In essence, it will be able to weigh the amount of carbon tied up in the world's forests.