Understandably any SDLV with an inline payload requires launch tower modifications. But what about modifications to the pad below? Can the hybrid inline-payload with sidemount-engines be flown without changes to the existing launch platforms, flame ducts, etc? Is that what lets it fly soon?
Quote from: notsorandom on 06/19/2010 01:30 amThe take on side mount vs inline is interesting, particularly in regards to side mount then transition to inline. I worry a bit that the study was a bit biased to side mount since that is what they started looking at and then added the inline configuration later. I'm sure they did a very good job with the study but it does look like they reached some conclusions that were different then Boeing and Direct. This study gives significantly higher estimates on time frames and costs. It will be interesting to hear what comments the Direct guys have. Boeing as well but I don't know if anyone that was involved with that study posts here. It would seem like doing a side mount and then doing inline would be the most expensive path to take. If an inline configuration is what is ultimately wanted then not developing a side mount version first would save billions of dollars. For the extra once only pad modifications and development an inline has much better performance. And thats even if a side mount is cheaper which the Direct team claims it is not.I think the issue here is that the sensibilities of 'straight to inline' are tempered with the need for a really 'quick and dirty' test vehicle to justify keeping the current workforce over the transition period. Hence the emphasis on sidemount?
The take on side mount vs inline is interesting, particularly in regards to side mount then transition to inline. I worry a bit that the study was a bit biased to side mount since that is what they started looking at and then added the inline configuration later. I'm sure they did a very good job with the study but it does look like they reached some conclusions that were different then Boeing and Direct. This study gives significantly higher estimates on time frames and costs. It will be interesting to hear what comments the Direct guys have. Boeing as well but I don't know if anyone that was involved with that study posts here. It would seem like doing a side mount and then doing inline would be the most expensive path to take. If an inline configuration is what is ultimately wanted then not developing a side mount version first would save billions of dollars. For the extra once only pad modifications and development an inline has much better performance. And thats even if a side mount is cheaper which the Direct team claims it is not.
Finally.... (is there a smiley for an exhausted smile?!).Whatever configuration they end up choosing, I hope we can all move forward to support it with verisimilitude and little controversy.
Quote from: MATTBLAK on 06/19/2010 03:01 amFinally.... (is there a smiley for an exhausted smile?!).Whatever configuration they end up choosing, I hope we can all move forward to support it with verisimilitude and little controversy.I know we are all in high spirits tonight because of this great bit of new information...but all in all nothing has really changed. This study was ordered before FY2011, and things were wrapped up because FY2011 stated SDHLV was no longer relevant. The only hope for SDHLV is that congress picks this document up and gives it a read and it persuades them to make a change. We all have been waiting on the inevitable compromise since Obama took office, I'm just hoping Congress will wake up and make a change in time. This presentation has a wealth of information in it, but it is all for nothing if those in Congress don't do something about it!
Quote from: gladiator1332 on 06/19/2010 03:31 amQuote from: MATTBLAK on 06/19/2010 03:01 amFinally.... (is there a smiley for an exhausted smile?!).Whatever configuration they end up choosing, I hope we can all move forward to support it with verisimilitude and little controversy.I know we are all in high spirits tonight because of this great bit of new information...but all in all nothing has really changed. This study was ordered before FY2011, and things were wrapped up because FY2011 stated SDHLV was no longer relevant. The only hope for SDHLV is that congress picks this document up and gives it a read and it persuades them to make a change. We all have been waiting on the inevitable compromise since Obama took office, I'm just hoping Congress will wake up and make a change in time. This presentation has a wealth of information in it, but it is all for nothing if those in Congress don't do something about it!I hear you... And hear that sound? That's merely the 'Fat Lady' clearing her throat.
Does make a great "what-would-have-been-if", tho...
I hope they kill shuttle-derived. A new HLV should be developed from scratch, designed for low operational costs.
I will have to read the article more thoroughly later on. However, at first glance, I've got the feeling that JSC may have done the usual NASA thing and chosen the most expensive path possible, given the objective and tools to hand. The hybrid with the side engine pod and an ET-style oval LOX tank seems to be attempting to backwards justify the side-mount.Nonetheless, it is good to see that NASA have finally acknowledged that D-SDLV is viable and not breaking any laws of physics.
Quote from: Ben the Space Brit on 06/19/2010 02:22 pmI will have to read the article more thoroughly later on. However, at first glance, I've got the feeling that JSC may have done the usual NASA thing and chosen the most expensive path possible, given the objective and tools to hand. The hybrid with the side engine pod and an ET-style oval LOX tank seems to be attempting to backwards justify the side-mount.Nonetheless, it is good to see that NASA have finally acknowledged that D-SDLV is viable and not breaking any laws of physics.I have to agree..they not want an inline, so lets pick the most expensive way to do an inline vehicle to make sidemount look good.
The recoverable propulsion module plus the side mounted SSME configuration does stir the imagination.