High Altitude Ballooning

High Altitude Balloon (HAB) Dec 3, 2011 Launch (FHSU Phys 100 class project)

Notes (from EXTREMELY HELPFUL discussions with Paul Verhage, check out http://www.nearspacenetwork.com):

NOTAM (Notice to Airmen for HiBall) Phone Number: 877.487.6867

Don't launch if the winds are in excess of 10 mph. When filling the balloon, fill with no regulator. Use cotton or latex gloves to handle the balloon. Fill balloon with a 1" PVC pipe with end-cap adapter to gas line (the PVC has a hook on it so a digital fish scale can be attached). Fill the balloon so that the lift force exceeds the payload weight by about 2.5 - 3 lbs. (If the lift force exceeds the payload weight by only ~1 lb it is possible to achieve neutral buoyancy!) To tie off balloon: twist rubber and then tie string around the balloon's neck where the rubber is thick, then fold the neck up and wrap with duct tape. Put about 20 ft of line between the balloon and parachute.

Trajectory predictions

http://habhub.org/predict/

http://nearspaceventures.com/w3Baltrak/readyget.pl (Hays airport is HYS)

GPS/Radio Tracking (N8VRN)

http://aprs.fi/

Latex Weather Balloon ($90), http://www.amazon.com/30ft-Professional-Weather-Balloon-1200g/dp/B00513FWQI

Specifications:

mass = 1.2 kg, 10ft diameter at release, 30 ft diameter at burst Nominal lift: 7.6 lbs Maximum lift: 15 lbs Nominal burst altitude: 115,000 ft

Parachute ($55), 6ft, 173 g or 6.1 oz, http://www.the-rocketman.com

Specifications:

Weight: Descent speed: 6.5 lb (4.77 m/s, 15.65 ft/s) 8 lb (5.39 m/s, 17.67 ft/s) 11.5 lb (6.35 m/s, 20.82 ft/s) 17 lb (7.72 m/s, 25.32 ft/s)

String