A Helium-filled Balloon Ascending with External Sensors. This balloon was released from a parking lot in Treynor, Iowa. The sensors attached to the balloon collect data so that we may plot temperature, air pressure and relative humidity. The balloon reaches an altitude of roughly 100,000 feet. This altitude on earth approximates the air pressure that is recorded on the surface of Mars! (Check the information on ARES, a Mars airplane.) The balloon is released from a pre-determined site and the landing location is calculated by taking into account the wind velocity. The balloon rises until it finally breaks, begins it's descent and the payload parachutes to the ground. The payload contains a GPS (Global Positioning System) unit which transmits back to the search team. The payload also consists of a temperature sensor, a relative humidity sensor and an air pressure sensor. The data is collected and analyzed. Part of the initial problem is to calculate where the balloon will land. The wind vector will dictate the balloon's flight path. How is this done? What is important to know? Wind velocity? Wind direction? Make yourself a practice problem and show how you could explain the balloon's flight path to a classmate or a parent.

http://ois.unomaha.edu/aia/pix_scan/temp_curv3.jpg This link shows a graph of temperature and relative humidity vs. time of day. What do these plots show? Is air temperature directly related to altitude? What happens to the temperature as altitude increases? (Note: The green line is temperature outside the sensor box and the black line is temperature inside the box.) Is there a difference between the temperature inside and outside the box? This flight was conducted in the summer of 2003. After the balloon landed, there seems to be changes in the relative humidity and the temperature. Can you guess why? ----------------------------------------------------- For information regarding the 2004 Aerospace Education Teachers Workshop, please contact Dr. Michael Larson at (402) 554-3424 or mlarson@unomaha.edu. ----------------------------------------------------- Here is a link to a map of the Aviation Weather Centers. Weather is important to a balloonist or a pilot. Why? http://aviationweather.gov

The problem is to find the profile of the atmosphere by comparing air pressure and temperature with their relationship to altitude. What would you expect the temperature and pressure to do as altitude increases? Sketch a graph (or choose appropriate points to build a graph) to show the relationship between altitude and air pressure. Build another graph (or use the same page) to show the relationship between altitude and air temperature. How do these graphs compare to the graphs we examined earlier? (pressure and temperature vs time) The Internet address for the page referring to the UNO BalloonSat Launch is: http://cosmos.ssol.iastate.edu/HABET/Home.html Then, click on 'missions' and select 'Recent Missions 2003' followed by 'HABET L64'. You should then find the data you are looking for near the bottom on the page by 'BalloonSat HOBO Data Correlated with GPS telemetry'.