EOSS204 was the second EOSS flight for the NOAA/LASP Tropopause Temperature Profiler which is designed to use an optical fiber to make in-situ measurements of temperature near the tropopause. The idea is to lower a length of optical fiber from the balloon payload and interrogate it by sending laser pulses down the fiber and determine temperature from the Raman scattering within the fiber. The first time this was tried on EOSS199, the fiber broke after about 50 meters of fiber were reeled out. The fiber that time was 200 microns in diameter with no protective coating. This time the glass
