When Is A Climate Satellite Not Exactly A Climate Satellite?

I have just been at a beautiful presentantion at the British Interplanetary Society in London, by Jessica Housden of EADS-Astrium about the upcoming ESA “EarthCARE” satellite (beautiful especially to us engineering boffins that is).

Designing a Spacecraft to Observe Climate Change

Understanding of the atmosphere is a continual process, with scientists all over the world endeavouring to determine how our atmosphere works and how it is changing. One such mission, EarthCARE, will be observing several processes which will help scientists. How will this be done and how will the spacecraft work?

Jessica Housden is a systems engineer for the EarthCARE mission, which will observe water content and aerosol distribution in the atmosphere.

Ms Housden said that EarthCARE, designed to look at clouds and aerosols, will be up there for 4 years from around 2013 (don’t bet your house on that though…there’s lots to learn before it can actually fly).

Upon hearing that I suddenly realised something confirmed during the Q&A session later: the climate-change EarthCARE satellite is not exactly a satellite to study the climate.

For a start, 4 years are way too short a time to see what climate is doing, let alone to see it changing.

You see, EarthCARE is a climate-change satellite. Its measurements will be used to (surprise, surprise!) help climate modellers improve their models (as everybody knows, clouds have been particularly badly modelled up to now).

After all, that’s what it “says on the tin” (“Spacecraft to observe Climate Change“, not “Climate“). Nothing to fault EADS-Astrium for…still, I suspect in the upcoming future one will have to be careful about this apparently minute distinctions.

What about the Climate then? Well, EarthCARE would be a good starting point. For example one of its instruments is designed to measure incoming and outgoing fluxes, thereby answering many of the questions we still have about the planetary energy budget.

But you’d need a constellation of EarthCAREs for proper climate research, perhaps 5 or 6, if only to observe a particular spot more than once a month. And you’d need also a steady supply, to have enough of them up there despite the relatively-short 4-year lifetime.