Wes and Robert study the atmosphere. To do this they send up a big helium balloon that has a small box dangling from a string. In the box has an antenna that can communicate with up to 8 satellites, and several sensors that measure things like temperature, pressure, and moisture. The fancy name for this balloon and sensor package is called a radiosonde. The information that comes back to their computers is called an upper-air sounding. The data is graphed to show what's going on in that atmosphere, on that day, in that location. Wes and Robert are part of a team that launches balloons every 3 hours! The idea is that the more data they collect the more accurate their "profile" or picture of the atmosphere will be. Also, they look for changes in the atmosphere as the ship moves along its track.