7 ms·
Test fire for the launch of a commercial satellite (AMOS-6), which had been scheduled for a few days hence (and now presumably delayed, along with the rest of t
by rst 10y ago
Test fire for the launch of a commercial satellite (AMOS-6), which had been scheduled for a few days hence (and now presumably delayed, along with the rest of their launch schedule, pending further investigation). It might conceivably have been during fueling/de-fueling around the test. It's not yet clear from public reports whether the payload was attached at the time of the test-fire; sometimes they are, sometimes they aren't.
(Note that fueling operations for Falcon 9 got a whole lot trickier when they switched to use of super-cooled fuel and oxidizer, to increase density -- if that stuff gets warmer, its volume increases to more than that of the tank, but it's still liquid, so you can't just vent it off.)
- deleted 10y ago[deleted]
- ars 10y ago> of a commercial satellite (AMOS-6) According to wikipedia this is related to the AMOS-2 staelite leased by Facebook to provide internet coverage in part of Africa. An interesting clause in their contract is: "The parties have agreed to the right to terminate the contract if Amos-6 and the ground gateways in France, Italy and Israel are not ready for service by January 1, 2017" So this fire could have wider repercussions if SpaceX doesn't get a new launch ready in time. (Unless that same contract also has a clause about SpaceX failure vs IAI failure.) > but it's still liquid, so you can't just vent it off. You can vent off liquid to keep the pressure down, but since it's heavier than air it will just add to the fire. Unless maybe they have some sort of piping system connected to the vent to route the extra fuel elsewhere.
- 0xffff2 10y agoUnless they happen to have a backup satellite already built, nothing SpaceX can do is going to accomplish this mission in 2016. There's no chance whatsoever that IAI is going to crank out a new satellite in just 3 months.
- ceejayoz 10y agoAll of SpaceX's launches are likely on hold for a few months, anyways.
- cmdrfred 10y agoSo does that put the rocket in a situation where its either launch or warm up and explode? I'm adventurous, but I don't want to be strapped to that thing if thats the case.
- avian 10y agoI'm sure it's not like that. Pressure relief valves aren't exactly rocket science.
- dogma1138 10y agoYou can't vent rocket fuel, the kerosine will ignite from the expansion and the friction in the valve alone. Venting liquid oxygen is also a really really bad idea.
- dandelany 10y agoOn the contrary, venting LOX is very common and easily visible in the lead-up to nearly every Falcon 9 launch. Google "falcon 9 lox vent" for plenty of videos/photos.
- dogma1138 10y agoThe "venting" you usually see isn't LOX, it's condensed water vapor, there are small bleeder valves in the LOX tanks and the fuel line but they are not designed or used for emergency pressure relief.
- TrevorJ 10y agoThey definitely do vent LOX boiloff.
- dogma1138 10y agoYes through the bleeder valves but a bleeder valve isn't an emergency pressure release valve. Bleeder valves are designed to bleed gas from a system which contains a liquid. They aren't designed to be used to relieve pressure in an emergency situation, infact under high enough pressure they stop working all together. In a more common setting you see these types of valves on breaks and on heating systems that use hot water, while they do bleed steam they bleed it in order to prevent the accumulation of gas and air bubbles within the system not to control the pressure.
- mikro2nd 10y agoInterested to know more about the fuels... when I searched for info about Falcon-9 fueling a week or two ago (having briefly conceived of a semi-idle interest in rocket propellants) I read it was RP-1 plus oxidiser - so basically "just" high-spec kerosene. That doesn't jibe with supercooling in my mind... Please enlighten us further.
- Retric 10y agoLiquid O2 aka oxygen is a common and cryogenic oxidizer. Loading cold liquid fuels also has benefits like lower volume, but few things stay liquid at cryogenic temperatures. PS: When dealing with rockets oxidizer is also a fuel because they need both it and something to burn.
- DigitalJack 10y agoFor oxygen to be liquid it needs high pressure and low temperature.
- shoegumfoot 10y agoActually, atmospheric pressure is enough, and oxygen boils at a slightly higher temperature than nitrogen.
- DigitalJack 10y agothanks, I should have said "or."
- deleted 10y ago[deleted]
- Tuna-Fish 10y agoThey chill the fuel and oxidizer to slush, just above their freezing point, to fit more of it into the same volume and save on structure.
- angryspacesheep 10y ago