Briefs: N2O hazards; BonNova test; Starchaser business

Starchaser seems more interested in their merchandising and exhibiting than they are in developing their technology. I haven't heard of any significant progress in their manned launch program since they drop tested a capsule a few years ago. Maybe they're just concentrating on selling trinkets until the spaceport is completed.

Posted by RRU185 at 07/29/07 21:11:06

Good analysis by Charles F. Radley! But I still consider thermal decomposition of the N2O as an other possible reason for the tragedy. Normally the N2O is at its saturated condition. This means, the slightest pressure drop when flowing through tubes, valves etc. causes bubbling. And bubbles can be a source of adiabatic compression and therefore a source of ignition. This is specially the case when you close valves and "water hammering" occurs. This can be supported by flammable particles , copper alloys which can act as additional catalysts. It needs only about 0.15 Joule in the vapor phase to initiate a decomposition. Keep also in mind that N2O is a solvent for hydrocarbons, specially at supercritical conditions. The paramedics reported burnings of the skin, you don't have this when the tank just ruptured (every paramedics wit ha right mind can distinguish between burnings and frostbites.
N2O is a lazy oxidizer, but sometimes it can be a beast!

Posted by Bruno Berger SPL at 07/29/07 23:45:42

There are numerous small N2O tanks utilized in the high performance automotive and model rocketry hobby. Many of these tanks and associated plumbing experience rather rough handling in extreme temperature conditions and fluctuations (car trunks, engine compartments, and lugged around in the field) I've never heard of any accidents such as tanks exploding until this tragedy. Makes me suspect something obviously wrong (may not be so obvious now following the explosive destruction) occurred. If the storage tank exploded then I would suspect something closely associated with it. Sounds like this test has been performed successfully several times in the past. So I would suspect something mechanical that was recently altered or damaged, perhaps a common procedure not followed or overlooked in close proximity of the tank.

Posted by Doug Gard at 07/30/07 04:07:50

What about another cause since the break down of the N2O seems unlikely esp since even with a catalyst it has to reach 650C also I never seen this happen even in dragsters that have crashed very hard and have dealt with the gas myself on vehicles.
I figure other causes could be possible contamination of the lines with a hydrocarbon such as a lubricant or hydraulic fluid from a leaking valve.
Also maybe the transport truck tank car may have been contaminated with a hydrocarbon such a mixture then would be a bomb just waiting to go off.
Another might be a malfunction of the nitrogen pressurization system and the tank just ruptured and loose liquid N2O being an oxidizer might ignite various materials that can burn though not as violently as lox but it would still be very energetic.

Posted by Ruri at 07/31/07 22:40:11

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