Quote from: arachnitect on 10/25/2013 03:00 amQuote from: a_langwich on 10/25/2013 01:49 amSo does that mean they are firing directly onto the top of the LH2 or LOX tank of the Centaur (DEC I guess?) in an abort? Yikes!LH2 tank is forward on Centaur.CST-100 SM is a larger diameter than the Centaur and the abort motors angle outboard a bit, so the plume may not actually impinge on the upper stage.Does it even matter though? Back in the days of "the stick" I remember there being a lot of talks about abort modes. I think somebody knowledgeable said that the LAS has to out run an upper stage RUD, in which case it doesn't matter if the abort motors vaporize the upper stage. I imagine that as long as you have a bit of clearance, by the time the plume torches the upper stage, the capsule is already accelerating away from the remains of the LV.Doesn't matter for that case, but consider some of the pad aborts actually seen in the past, where the launch vehicle aborted very close to the pad. In some of those, the launch escape system fired while the rest of the rocket stayed on the pad: it would be less handy if the launch escape system caused the entire launch vehicle to explode, destroying the pad. More generally, if the upper stage is NOT blowing up, it seems like it would be a safety win to not go ahead and make it blow up. In other words, promoting a whole bunch of lesser cases to the worst case doesn't seem like a good attribute. So yes, I think it does matter. But you are right, maybe the plumes don't impinge or not much anyway, and the short time frame makes it reasonable. I'm sure those concerns have been raised, and answered in some way.
Quote from: a_langwich on 10/25/2013 01:49 amSo does that mean they are firing directly onto the top of the LH2 or LOX tank of the Centaur (DEC I guess?) in an abort? Yikes!LH2 tank is forward on Centaur.CST-100 SM is a larger diameter than the Centaur and the abort motors angle outboard a bit, so the plume may not actually impinge on the upper stage.Does it even matter though? Back in the days of "the stick" I remember there being a lot of talks about abort modes. I think somebody knowledgeable said that the LAS has to out run an upper stage RUD, in which case it doesn't matter if the abort motors vaporize the upper stage. I imagine that as long as you have a bit of clearance, by the time the plume torches the upper stage, the capsule is already accelerating away from the remains of the LV.
So does that mean they are firing directly onto the top of the LH2 or LOX tank of the Centaur (DEC I guess?) in an abort? Yikes!
Quote from: a_langwich on 10/25/2013 01:49 amQuote from: Jason1701 on 10/25/2013 01:38 amQuote from: a_langwich on 10/25/2013 01:24 amIs this the RS-88? Are there four used for pad abort and launch escape, and are they the bulges on the side of the "service module" or whatever it's called for CST-100? I haven't seen much on that part of the design, eg drawings that show the layout of the pad abort motors and how they (and their nozzles) are situated inside the module. Anybody have links?They're not inside the four faired volumes, but on the backshell of the service module.http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2011/10/CST_100_Wind_4.pngThanks for the diagram! So does that mean they are firing directly onto the top of the LH2 or LOX tank of the Centaur (DEC I guess?) in an abort? Yikes!No, I believe the centaur/CST-100 adapter has four open and deflected paths with some sort of blow-out panels - one for each abort engine. In this image you can see the darker panels that should allow the deflected thrust to exit if an abort occurs. I could be wrong, but I think that's how it will work.
Quote from: Jason1701 on 10/25/2013 01:38 amQuote from: a_langwich on 10/25/2013 01:24 amIs this the RS-88? Are there four used for pad abort and launch escape, and are they the bulges on the side of the "service module" or whatever it's called for CST-100? I haven't seen much on that part of the design, eg drawings that show the layout of the pad abort motors and how they (and their nozzles) are situated inside the module. Anybody have links?They're not inside the four faired volumes, but on the backshell of the service module.http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2011/10/CST_100_Wind_4.pngThanks for the diagram! So does that mean they are firing directly onto the top of the LH2 or LOX tank of the Centaur (DEC I guess?) in an abort? Yikes!
Quote from: a_langwich on 10/25/2013 01:24 amIs this the RS-88? Are there four used for pad abort and launch escape, and are they the bulges on the side of the "service module" or whatever it's called for CST-100? I haven't seen much on that part of the design, eg drawings that show the layout of the pad abort motors and how they (and their nozzles) are situated inside the module. Anybody have links?They're not inside the four faired volumes, but on the backshell of the service module.http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2011/10/CST_100_Wind_4.png
Is this the RS-88? Are there four used for pad abort and launch escape, and are they the bulges on the side of the "service module" or whatever it's called for CST-100? I haven't seen much on that part of the design, eg drawings that show the layout of the pad abort motors and how they (and their nozzles) are situated inside the module. Anybody have links?
Looks pretty sweet on top of the Atlas doesn't it?
Am I the only one who finds it difficult to get more than a modicum of anything but old news about Boeing's vehicle and its progress in development.
Dual engined Centaur had the PDR...
Quote from: newpylong on 12/16/2013 02:32 pmDual engined Centaur had the PDR... Did this just happen? Good, if that is the case. Do you have a link/source?
Here you gohttp://events.aviationweek.com/html/ad13/Nov%2013_Mulholland.pdf
Quote from: manboy on 12/13/2013 10:54 pmHere you gohttp://events.aviationweek.com/html/ad13/Nov%2013_Mulholland.pdfOn page 4 of this presentation it mentions "Solar Panels (Mission Kit)" pictured on the bottom of the service module. Is this a new development as I thought the CST-100 was battery only... Or is this an option for longer duration missions or something?
Terry Lorier:"In the past several weeks, the Aerojet Rocketdyne team conducted a series of eight tests on two Launch Abort Engines meeting or exceeding all test parameters,""The success of this most recent test series clears the way for our team to proceed into qualification and production of the engine in the next phase of the program."
Boeing Defense tweet: @BoeingDefense 3hBig milestone! MT @AerojetRdyne Good morning @Boeing & @Commercial_Crew! We finished dev testing of CST-100 engine http://tinyurl.com/nx9b7nb QuoteTerry Lorier:"In the past several weeks, the Aerojet Rocketdyne team conducted a series of eight tests on two Launch Abort Engines meeting or exceeding all test parameters,""The success of this most recent test series clears the way for our team to proceed into qualification and production of the engine in the next phase of the program."
It seems to me like the CST-100 is basically out of the game for commercial crew or any other use for that matter. It seemed to be the safe and traditional fallback in case Sierra Nevada folded or Dragon didn't live up to performance / schedule expectations. Now that both of the longshots seem to be on track, what place does CST have? The clamshell design and pusher LAS are innovative, but the other options use pushers and have pinpoint landing capabilities, something NASA probably cares more about than how easy it is for boeing to outfit the interior.Does CST still have a shot at being tested? If so, why?
Quite the opposite. It is further along, less risk, etc
Quote from: Jim on 01/26/2014 10:41 amQuite the opposite. It is further along, less risk, etcCan you expand on how it is "further along"? I personally find it difficult to see the big picture.