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Infrared Imaging

Out of 33 attempts, only nine photographs were taken on this flight. Of those, only one was properly exposed. In the image below, the white stripes are clouds. The light pink near some of their edges are shadows of the clouds cast on the ground. Small ponds are dark blue. The chlorophyll in plants reflects infrared very well and shows up as a bright red. Plowed fields show up as darker patches.

Flight TV01D

Geiger Counter Data

As is typical, TVNSP flew the Aware Electronics RM-60 PC Geiger counter. Once above the ground, the Geiger counter will only detect cosmic rays.

The graph above shows that the flux of secondary cosmic rays increases with altitude as the balloon rises higher into the shielding atmosphere. At an altitude of around 62,000 feet the atmosphere is no longer creating secondary cosmic rays and the Geiger counter begins detecting the primary, or the original cosmic rays.

Cosmic rays is a fascinating subject. You can read more about them at the University of Utah's cosmic ray page, at http://www.cosmic-ray.org

Flight TV01D

Insect Cabin Calibration Results

To properly monitor the pressure within the insect cabins TVNSP is developing, the output from the two pressure transducers must be calibrated. This flight shows that each transducer has a 0.5 volt minimum voltage that must be subtracted from each reading.

Calibration was accomplished by observing the drop in transducer output as the capsule ascended. In the standard atmosphere, the air pressure drops by a factor of two every 18,000 foot increase in altitude. The change in transducer voltages between altitudes of 18,000, 36,000, 54,000, and 72,000 where averaged. This average is then subtracted from the voltage at 18,000 feet to determine the base voltage of the transducer, which becomes the Y intercept in a transducer voltage to pressure function.

Because of weight, an environmental sounder was not flown on this mission. However the data from the insect cabins can be used to characterize the temperature and pressure of the atmosphere as a function of altitude.

The lowest air temperature encountered in a near space balloon flight occurs at the troposphere-stratosphere boundary, or at the tropopause. The altitude of the tropopause lowers in the winter and rises in the summer. It also changes as a function of latitude. In the above graph you can see that the tropopause occurs at an altitude of 45,000 feet.

The above graph illustrates that the air pressure drops as a logarithmic curve. How can we be certain that we're seeing a logarithmic curve here? In the next graph I plotted the same data (actually the spreadsheet did the plotting) but on a log-linear scale. The graph now shows a near-straight line.