Differences

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--- guides:hydrogen_vs_helium_fro_hab [2018/02/26 14:22] – [Helium:] rocketboy
+++ guides:hydrogen_vs_helium_fro_hab [2018/02/26 14:41] (current) – [Helium:] rocketboy
@@ Line 7: / Line 7: @@
   * **cons:** Highly Flammable, needs a registered business to acquire, extra precautions needed.
-==== Helium: ====
+===== Helium: =====
   * **pros:** Non flammable, available retail.
   * **cons:** limited natural resource.
@@ Line 15: / Line 15: @@
 === Difference in lift: ===
 Hydrogen has a density of about 0.0899Kg/cu m (at 1 atm 15C).
-Pure Helium has a density of 0.1786Kg/cu m however balloon grade helium is usually only 97% Helium – giving it a density of 0.2094Kg/cu m
+Pure Helium has a density of 0.1786Kg/cu m however balloon grade helium is usually only 97% Helium – giving it a density of 0.2094Kg/cu m.  Air has a density of 1.225Kg/cum – giving:
-Air has a density of 1.225Kg/cum – giving:
   * **97% Helium** a lift of about 1.01Kg/cu m
-  * **Hydrogen** a lift of about 1.13Kg/cu m – so about **12% better than Helium**.
+  * **Hydrogen** a lift of about 1.13Kg/cu m – so about **12% better**.
 === Altitude difference. ===
-In practice the difference between Helium and Hydrogen is much less in terms of altitude attained. For example a 1Kg payload on a HY-1000 balloon at 5m/sec ascent rate would typically achieve around 32.0Km (105,000ft) on 97%Helium and 33.1Km (108,000ft) on Hydrogen – so **only 3% better.**
+In practice the difference between Helium and Hydrogen is much less in terms of altitude attained. For example a 1Kg payload on a HY-1000 balloon at 5m/sec ascent rate would typically achieve around 32.0Km (105,000ft) on 97%Helium and 33.1Km (108,000ft) on Hydrogen – so only **3% better.**
 === Difference in price: ===
@@ Line 39: / Line 38: @@
 The most likely cause of ignition for HAB use is probably a static discharge between the filled balloon and personnel or structures.  During Operation Outward (WW2 launch of circa 100,000 hydrogen met balloons) there were several instances of the balloons catching fire due to static discharge between the balloons and filling tents.  In some cases personnel were badly burned (but no fatalities).
+Also see [[guides:hydrogen|Suggested Safety Considerations when Using Hydrogen for Balloon Launches]]