#SpaceShipTwo has experienced an in-flight anomaly. Additional info and statement forthcoming.
https://twitter.com/virgingalactic
Damn!
https://twitter.com/virgingalactic
Damn!
You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
sounds like engine exploded.That debris looks to be too far apart for it to have hit the ground in one piece. Metal fatigue? An explosion?
Anyway, very sad.
Thanks HVM for keeping us updated.
Such a tragedy. Honestly, it's surprising to me that they would need onboard human pilots in this day and age to test a new rocket engine. For the level of risk involved, you'd think that SpaceShip 2 would have automated test flights. I can't imagine trying to punch out at that level of thrust.
agreed, doesn't space-X do engine testing on unmanned rockets?
Actual in-operation manned flight is important, and manned test flights are also important. But I should think that tests at this level for this purpose (a different fuel mixture in a newer engine) should not be manned. It feels like an unnecessary risk.SpaceX doesn't have manned rockets currently so yeah. This is a suborbital spaceplane, designed for space tourism, I think manned testing is important for a variety of reasons.
[Joel Glenn Brenner] minced no words, saying that even if this flight had been successful, there is no way this particular type of engine would have succeeded in powering SS2 into space.
SS2 does use nitrous oxide as the liquid oxidizer.Wikipedia said:Hybrid rockets exhibit advantages over both liquid rockets and solid rockets especially in terms of simplicity, safety, and cost.[2] Because it is nearly impossible for the fuel and oxidizer to be mixed intimately (being different states of matter), hybrid rockets tend to fail more benignly than liquids or solids. Like liquid rocket motors, but unlike solid rocket motors, hybrid rocket motors can be shut down easily and the thrust can be controlled with a simple throttle.
...
Generally, well designed and carefully constructed hybrids are very safe. The primary hazards associated with hybrids are:
- Pressure vessel failures - Chamber insulation failure may allow hot combustion gases near the chamber walls leading to a "burn-through" in which the vessel ruptures.
- Blow back - For oxidizers that decompose exothermically such as nitrous oxide or hydrogen peroxide, flame or hot gasses from the combustion chamber can propagate back through the injector, igniting the oxidizer and leading to a tank explosion. Blow-back requires gases to flow back through the injector due to insufficient pressure drop which can occur during periods of unstable combustion. Blow back is inherent to specific oxidizers and is not possible with oxidizers such as oxygen or nitrogen tetroxide unless fuel is present in the oxidizer tank.
- Hard starts - An excess of oxidizer in the combustion chamber prior to ignition, particularly for monopropellants such as nitrous oxide, can result in a temporary over-pressure or "spike" at ignition.