Presentation on theme: "Helium or Hydrogen? GPSL Forum August 1, 2008 Mike Morgan N0MPM EOSS."— Presentation transcript:
Helium or Hydrogen? GPSL Forum August 1, 2008 Mike Morgan N0MPM EOSS
Agenda Background –Why an Issue? –Others using H 2 –Hydrogen Basics ISSUES to Discuss - Open Forum –Transportation/Safe Handling –Flammability/Static Mitigation –Balloon Fill Procedures –Performance –Intangibles
Why an Issue? Helium costs are going up – significantly –And its getting harder to source –Last EOSS – $80 plus transport, $56 Nov07 –For GPSL – includes transportation to site $132 per bottle He $ 56 per bottle H 2 Hydrogen is Flammable! –We need to learn how we can safely use Hydrogen Time to develop and review procedures before we find ourselves Out of Business with Helium
Others using Hydrogen NOAA/NWS –Today all sites east of Kansas City –Future plan to extend to all sites Space Data – Claims 15k launches –Typically 5 lb payloads A Few Amateur Balloon Groups Many foreign launch organizations and US teams launching outside CONUS
Hydrogen Basics Flammable –Wide flammable range (4% to 74%) –Also explosion potential Very low ignition energy required –Makes it more prone to static discharge ignition –Can self ignite upon venting to air Flames are almost invisible –Can cause serious burns Hard to contain –Valves and fittings leak –Balloon leak rate increases (40% higher diffusion rate)
Open Discussion Forum –Transportation/Safe Handling –Flammability/Static Mitigation –Balloon Fill Procedures –Performance –Intangibles
Transportation/Safe Handling Transport regulations similar to He Assure no leaking valves inside vehicle –Fire –Asphyxiation Recommend NO Manifolds - 1 Bottle at a time Standards recommend SS tubing and diaphragm valves Never crack open valves to atmosphere PPE - Nomex, face shield, gloves etc
Flammability/Static Mitigation Minimize air in hose/balloon Minimize Static Potential –High humidity, low wind, fill rates etc Grounding - all personnel, H2 delivery system How to stabilize balloon fill in windy conditions? –Increases # of potential static touches to balloon Use Anti Static treated balloons? –Grounding Balloon neck not good enough Spark proof tools
Balloon Fill Procedures Low fill rates –Difficult in high wind conditions Leak detection How to assure NO chance of burst during fill? –Evidence shows just the burst can cause enough static energy to cause explosion Should we develop a remote fill and launch system??
Performance Hydrogen is 8% more buoyant Much higher diffusion rate through balloon wall (40% higher rates) Most data agrees that hydrogen will result in slightly lower burst altitude Most experience has been with small payload balloons…<6 lbs
Intangibles What IF we have an accident with injuries? –Could be a long way from medical help What is the perception with our Customers –Are we putting students at risk? (real or perceived) How do we assure proper training and sustainable procedure adherence? How do we keep the area clear from the uninformed public, etc.??
Last Minute Thoughts? Can We Do This? Should We Do This?
Cylinder Sizes Size (inches) DOT NumberAirgasAirco Air ProductsPraxairScottMatheson MG Industries 9x60 3AA A T K IL 300 9x56 3AA2265 Or 3AA B K A IA /2x31 3AA C Q B 2 6x24 3AA D1 G C x20 3AA D F D x15 3AA x15 3E1800 LB 2 2x16 3E1800 LX 7X LG ELB 7X LB 41/2x31 3AA2015 E E Med.E ANE ER E 12x8 8AL A Lab380 XF IB x48 48A A1 FX XL 1F x52 4AA AA FA XG 1K x53 48A A3 FC XP IJ 65 9x161/2 39NRC D L TAP Scotty III Maxicyl 121/2x181/2 48A x53 3AL A B(AL) ALS Al 1R ISOAL 7x38 3AL A C(AL) ALQ BL 2R 8OAL 7x21 3AL A 30A DL(AL) ALH CL 3R 33AL
What we dont know – How altitude, temperature and humidity impact static discharges All changes to fill & launch checklists What additional resources might be needed –Leak detection – soap solution can freeze –Fire detection and suppression –Safety equipment – hard hats, face shields, fire retardant clothes, etc. –Additional launch staff – launch safety boss? TBD as we learn more