1. VT-HUN1013 Skyward Sword Milestone presentation Sverrir Haraldsson

2. HAB Balloons  Several types of HAB balloons being used for high altitude research and photography  Meteorological weather balloons, categorized in grams (150-3000 grams), Short flight time.  Zero pressure envelopes, long flight time  Super pressure envelopes, extra long flight time

3. Balloon selection  Balloon selection is dependent on project size and objectives.  Questions that needs to be answered before optimizing selection.  Altitude?  Payload weight?  Flight time?  Traveling distance?  Cost?  Reliability?  Regulations?

4. Balloon selection  Our objectives  30-40 km (10-5mb) altitude  2-3 hour flight time  300 km maximum traveling distance  > 4 kg payload weight  Limited budget of approx. $10,000

5. Balloon selection  Project cost quickly rises when payload increases  Example

6. Final decision  Balloon  3000 gr meteorological Latex balloon from Kaymont  Flight time  2-2.5 hours, depends on the ascent rate  Altitude  At least 30 km for decent photographs of space and earth

7. Inflation  Lifting gas  Helium; Expensive, non-explosive, gives second best buoyancy after Hydrogen or (8% less)  Filling volume  Depends on ascent rate, exploding altitude and payload weight.  Lifting capabilities  Gross lift= balloon + payload  Balloon Buoyancy / free lift ( Archimedes' principle)Archimedes' principle  F buoyancy = V(ρ air - ρ He )-F gross

8. Lifting capabilities  The 3000 gr meteorological Latex balloon  1000-1500 gr free lift for 5-6 m/s ascent rate  Not linear with variations of balloon size  Should yield to 30-37 km burst altitude for 4 kg payload  Dependent variables  Exploding altitude  Ascent rate  Free lift  Gross lift  Expenses

9. Thank you The end