|
|
Thread Tools | Display Modes |
#7
|
|||
|
|||
SpaceX Capsule Explosion
In article , says...
On 7/16/2019 7:41 PM, Fred J. McCall wrote: David Spain wrote on Tue, 16 Jul 2019 13:58:46 -0400: On Rand Simberg's blog, George Turner postulated they (titanium values) were to allow engine restarts back in the days when Dragon V2 was supposed to use propulsive landing. With burst disks you don't get that capability but don't need it because Dragon V2 will use its chutes and ocean landings only. I'd have to study it more myself to know for a fact if that is true... That sounds wrong to me. These engines are throttleable and it shouldn't matter if the propellant system is pressurized. Set throttles to zero and the engine shuts off. Open the throttles and the hypergolics hit the combustion chamber again and the thing lights. Yeah unclear to me as well. Why would these check valves be used for any purpose other that to close in order to refill helium tanks between flights? The abort system's Super Dracos require *much* higher chamber pressure than the Dracos, so the system is not pressurized until an abort is initiated. Why they chose to do it this way, I'm not sure. Perhaps NASA didn't want super high pressure hypergolic propellant tanks docked to ISS. For it to effect propulsive landing you have to postulate a scenario whereby the helium gets past the propellants and is expelled out the engine thus allowing the helium supply to get below the propellant supply. But I don't see how the helium gets past the liquid propellant being throttled. Physical chemistry is not my forte. Am I missing something here? Also what bursts the burst disks? I assume something will be used to over pressurize the helium? Or will they burst when the helium tank itself is pressurized? Thus the fueling operation would require hypergolic propellant loading before helium tank pressurization where that wasn't the case before. Correct? See above. They burst when the hypergolic system for the Super Dracos is pressurized, which is only when an abort is initiated. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
SpaceX Dragon 2 capsule destroyed in abort motor ground test | Jeff Findley[_6_] | Policy | 59 | July 12th 19 08:30 AM |
Latest candidate for SpaceX pad explosion | Fred J. McCall[_3_] | Policy | 50 | October 28th 16 06:54 AM |
SpaceX Falcon 9 ? Possible Explosion | Jeff Findley[_2_] | Policy | 22 | October 9th 13 09:54 AM |
SpaceX capsule has 'new car' smell, astronauts say | [email protected] | Policy | 5 | June 2nd 12 08:09 PM |
Space Station's Robotic Arm Successfully Captures SpaceX Capsule | Sam Wormley[_2_] | Amateur Astronomy | 0 | May 25th 12 03:36 PM |