1. AAE 450 Spring 2008 Jerald A. Balta 3/27/2008 Propulsion Team/CAD Final Slides

2. AAE 450 Spring 2008 Balloon Cost Modifier  Balloon Cost Items –Balloon – Price quote from Aerostar International –Helium – Priced at $4.87 per cubic meter –Gondola- Constant Price of $13205.30

3. 3 Balloon Cost AAE 450 Spring 2008 Cost Trend Equation  y = -0.0011x2 + 30.62x + 3111.1  y= Cost  x=Balloon Payload

4. Balloon Model  Free Body Diagram  Two forces acting on Spherical Balloon –Buoyancy Force Defined by difference between masses of lifting gas and air multiplied by gravitational constant –Weight Buoyancy Weight

5. Derivation of Balloon Dimensions  Lifting Coefficient –Ρ g is density of lifting gas –Ρ a is density of air  Boyle’s and Guy Sac laws –Rho is density –P is pressure –T is Temperature

6. Derivation of Balloon Dimensions Continued  Combine Equations to determine lifting coefficient for different heights  Take into account 95% Gas purity and standard excess of 15% lifting gas  Final Equation for Volume of Gas in relation to Mass –V is Volume of lifting gas –M is total Mass

7. Gondola Costs Structures Cost of $1205.30 Material Welding Riveting Avionics Cost of $12000 One Battery Sensors  Total Gondola Cost of $13,205.30 Provided by Sarah Shoemaker, Structures Group, and Avionics Group

8. Ground Support and Handling Cost Modifier  Handling – Personnel required for handling of fuels, toxic materials, etc  Ground Support – Based on estimation of salaries of necessary personnel –Assumed $100/hour salary –6 engineers from all teams and one manager

9. Cost Modifier

10. References  Defense Energy Support Center, “MISSILE FUELS STANDARD PRICES EFFECTIVE 1 OCT 2007,” Aerospace Energy Reference, November 2007  Larson, W.J., Wertz, J.R., "Space Cost Modeling," Space Mission Analysis and Design, 2nd ed., Microcosm, Inc., California and Kluwer Academic Publishers, London, 1992, pp. 715-731.  Smith, Mike, Phone Conversation, Aerostar International, February 15, 2008  Tangren, C.D., "Air Calculating Payload for a Tethered Balloon System," Forest Service Research Note SE-298, U.S. Department of Agriculture - Southeastern Forest Experiment Station, Asheville, North Carolina, August 1980.