UK-built satellite to ‘weigh’ Earth's forests

The European Space Agency’s Biomass satellite, which is currently being assembled by prime contractor Airbus UK in its Stevenage space facility, will measure the carbon stored in the world’s forests

Biomass is the first satellite to carry a fully polarimetric P-band radar. The radar has a 70cm wavelength that will allow it to go through the whole forest layer and map the trunks and branches hidden below, unlike previous missions. This will help scientists better assess the effects of deforestation on climate change more accurately, significantly reducing the uncertainty around current measures.

The mission is expected to last five years, scanning the world’s forests every six months. People will be able to track the satellite as it orbits the Earth.

Maria Cody, head of ESA policy at the UK Space Agency, stressed that Biomass will allow scientists, as well as the wider public, to see “if there is a degradation or a destruction of forests" and "model what that impact will be and take action quite early on to correct that.”

Although Biomass is expected to be ready for launch at the end of next year, the satellite's main P-band radar has already been delivered to Stevenage, where engineers from L3Harris Technologies have overseen the attachment of the antenna-reflector to the satellite's main body, or bus.

The scientists behind the mission stressed the importance of Biomass as a way of raising awareness about the tangible impact of global warming. Moreover, the mission's length is also expected to allow climate change specialists to better track the advances of climate change and prepare for its consequences. 

Once in orbit, the satellite will take a scan of the lungs of the Earth, penetrating through canopies and building a 3D image of the global forests. The data obtained during the mission will be made publicly available, to provide everyone with consistent, impartial measures of all the Earth’s biomass. 

The project's science lead, Professor Shaun Quegan from the University of Sheffield, said the satellite's data would “help deforestation" as well as “foster the political will to look after our forests better, to give people information they can’t argue with that says, ‘Okay, we’ve got to do this better’.

“If you’ve got one instrument so when you switch it on, it’s giving the same stuff, time and time and time again, and they’re all the same, then it’s got the consistency and impartiality, that allows you to talk sensibly about the whole picture, which at the moment, you can’t do."

The plan is for Biomass to gather at least five years' worth of data, to be able to spot trends and changes in the global biomass.

"At the moment, the amount that's being emitted from forests - the uncertainty on that number is 50 per cent or a bit bigger, and I actually think 50 per cent might be optimistic," the National Centre for Earth Observation (NCEO) researcher told BBC News.

In addition to providing information on all the forests of the Earth the Biomass mission will also analyse topography and see where water used to run below the Earth's surface, and potentially identify areas of archaeological interest.

Although this mission will be the first to take a P-band radar into space, the technology was flown over a forest in Eastern England for the first time in the late 1980s. However, until now, these radar frequencies have been reserved for military use, with the US using them to detect missiles approaching European and North American coasts.

In order to allow the Biomass mission to go ahead, the ESA had to make a request to the International Telecommunications Union that would allow it to open up a small window in this sensitive part of the electromagnetic spectrum to enable a science application.

The ITU wanted the approval with the condition that Biomass would not operate over North America and Northern Europe. However, forests in these regions are already better understood than in more remote parts of the world.