The system is called Soluble Acidic Gases and Aerosols. We have two parts to it. One is a filter that's a bulk filter. It collects aerosols from very tiny sizes up to about 5 microns. So we measure 8 or 9 ions, tracers of pollution, sea salt, biomass burning, and dust. So the combinations or the ratios tells us something about the source of the air. Then we run the mist chamber IC sampler, which collects soluble gases and fine, submicron aerosols into a liquid. And we make injections right onto the IC on the airplane so we get data about 3 or 4 minutes after we collect the sample. And there the focus is primarily on nitrate and sulfate. Well the filter sampling, it's a manual system. So you got to put the filters in there and open the valves. So every few minutes I gotta get up and put in another filter, and take the ones out and put them back here in the cooler so they don't degrade. I think that we're going to see really clean air, but we're also going to see pockets of pollution from various sources. A long time ago we came down to the Southern Ocean on a NASA mission called ChemTropics, and the same idea we're trying to get into the tropics and find this really clean air. But we were seeing biomass burning plumes from Africa and South America in the middle of the Pacific Ocean. So I think we will see stuff like that. It's just not clear how much of an effect does that have. If you don't go after them and you just fly around, do you see them 10 percent of the time or 50, or...? We don't know. So that's why this mission is not targeting them. It's trying to sample them as they happen to be there. We're certainly going to hit them throughout the four seasons and in all different parts of the trip.