Quote from: clongton on 02/24/2012 05:11 pmWhile I am not wildly enthusiastic about what NASA has done to the recommended configuration that the President signed off on in October 2010, the fact remains that it incorporates almost all the systems changes that we recommended. So it has that going for it. In my opinion, SLS is too big and too expensive, unnecessarily so, but be that as it may, it will work well. CxP was depending on a 2-vehicle solution that would have cost so much that no real missions would be affordable, and made some very bad design choices that drove it over the edge, thus imploding on itself. But there is something else going for SLS as well that wasn't a factor before that may derail any attempts to kill it. There is a burgeoning commercial industry which is on the verge of stepping up and taking NASA's place wrt human spaceflight. Regardless of all the accomplishments of the past, historic glory can only carry the space agency just so far and for the last 40 years NASA has not sent a manned spacecraft BLEO. Well we have several companies on the verge of equaling that, one of whom have already orbited their spacecraft and successfully recovered it "for reuse" no-less. And *that* spacecraft (Dragon) is being designed to enable BLEO missions to the moon in *direct* competition to NASA's unbuilt Orion spacecraft. I don't believe that the Congress is willing to let the national space agency be overwhelmed by private companies doing things that NASA can't do, and for less money than NASA's minimum budget, if only to save face and not let commercial companies humiliate it. If NASA is allowed to stumble at this point then it's game over for NASA. Congress knows that and in my opinion won't allow that to happen. SLS-Orion, for all its enormous bloat, will fly.IMHO, and YMMV.Too big to fail... well, we've heard it before... I hope your right... because the alternative isn't pretty and will only delay things for years or more... Later! OL JR
While I am not wildly enthusiastic about what NASA has done to the recommended configuration that the President signed off on in October 2010, the fact remains that it incorporates almost all the systems changes that we recommended. So it has that going for it. In my opinion, SLS is too big and too expensive, unnecessarily so, but be that as it may, it will work well. CxP was depending on a 2-vehicle solution that would have cost so much that no real missions would be affordable, and made some very bad design choices that drove it over the edge, thus imploding on itself. But there is something else going for SLS as well that wasn't a factor before that may derail any attempts to kill it. There is a burgeoning commercial industry which is on the verge of stepping up and taking NASA's place wrt human spaceflight. Regardless of all the accomplishments of the past, historic glory can only carry the space agency just so far and for the last 40 years NASA has not sent a manned spacecraft BLEO. Well we have several companies on the verge of equaling that, one of whom have already orbited their spacecraft and successfully recovered it "for reuse" no-less. And *that* spacecraft (Dragon) is being designed to enable BLEO missions to the moon in *direct* competition to NASA's unbuilt Orion spacecraft. I don't believe that the Congress is willing to let the national space agency be overwhelmed by private companies doing things that NASA can't do, and for less money than NASA's minimum budget, if only to save face and not let commercial companies humiliate it. If NASA is allowed to stumble at this point then it's game over for NASA. Congress knows that and in my opinion won't allow that to happen. SLS-Orion, for all its enormous bloat, will fly.IMHO, and YMMV.
Quote from: clongton on 02/24/2012 05:11 pm.....But there is something else going for SLS as well that wasn't a factor before that may derail any attempts to kill it. There is a burgeoning commercial industry which is on the verge of stepping up and taking NASA's place wrt human spaceflight. Regardless of all the accomplishments of the past, historic glory can only carry the space agency just so far and for the last 40 years NASA has not sent a manned spacecraft BLEO. Well we have several companies on the verge of equaling that, one of whom have already orbited their spacecraft and successfully recovered it "for reuse" no-less. And *that* spacecraft (Dragon) is being designed to enable BLEO missions to the moon in *direct* competition to NASA's unbuilt Orion spacecraft. I don't believe that the Congress is willing to let the national space agency be overwhelmed by private companies doing things that NASA can't do, and for less money than NASA's minimum budget, if only to save face and not let commercial companies humiliate it. If NASA is allowed to stumble at this point then it's game over for NASA. Congress knows that and in my opinion won't allow that to happen. SLS-Orion, for all its enormous bloat, will fly.IMHO, and YMMV.I respect your enormous knowledge on this subject but in my opinion you are overly optimistic at where SpaceX stands with Dragon, particularly with regards to BLEO flights.
.....But there is something else going for SLS as well that wasn't a factor before that may derail any attempts to kill it. There is a burgeoning commercial industry which is on the verge of stepping up and taking NASA's place wrt human spaceflight. Regardless of all the accomplishments of the past, historic glory can only carry the space agency just so far and for the last 40 years NASA has not sent a manned spacecraft BLEO. Well we have several companies on the verge of equaling that, one of whom have already orbited their spacecraft and successfully recovered it "for reuse" no-less. And *that* spacecraft (Dragon) is being designed to enable BLEO missions to the moon in *direct* competition to NASA's unbuilt Orion spacecraft. I don't believe that the Congress is willing to let the national space agency be overwhelmed by private companies doing things that NASA can't do, and for less money than NASA's minimum budget, if only to save face and not let commercial companies humiliate it. If NASA is allowed to stumble at this point then it's game over for NASA. Congress knows that and in my opinion won't allow that to happen. SLS-Orion, for all its enormous bloat, will fly.IMHO, and YMMV.
Now that they have deleted the 5th SSME the next thing would be to go back to the STS ET capacity and fly the SRB with the central barrel omitted, a 4-seg SRB using the new designs. It will actually perform better than the as-designed SLS. Without the US it will lift in the neighborhood of 85 tons IMLEO. Add a single J-2X powered US and it will approach 120 tons.
Removing an SRB segment changes the thrust but not the burn time, right? Scaling all the masses and forces down by 20% would scale the payload down by 20% as well. In what way does your proposal differ from a uniform 20% reduction that enables it to perform better?
Quote from: Thunderbill on 02/27/2012 04:37 pmExcuse my ignorance but I take it from the article that the second test flight will be crewed and use the Delta IV Heavy Upperstage. When was this stage man rated?the first manned flight will be the 3rd flight of the Orion and the 2nd flight of the SLS. Orion will fly on a DIVH for its first flight in 2017 or so and SLS all flights following.
Excuse my ignorance but I take it from the article that the second test flight will be crewed and use the Delta IV Heavy Upperstage. When was this stage man rated?
Quote from: Thunderbill on 02/27/2012 04:37 pmExcuse my ignorance but I take it from the article that the second test flight will be crewed and use the Delta IV Heavy Upperstage. When was this stage man rated?Clearly, ICPS will be man-rated. If Delta IV Heavy CPS is the starting point for ICPS, there will have to be engine and flight control system modifications (to provide abort modes, etc.). Aerospace Corp. did a paper describing the needed mods a few years ago. It is all very possible. There is time - likely nine years from now until the first crewed flight.
Suppose that funding for the large upper stage never materializes. Is there a cheaper way to improve on block 1A to lift those rare payloads that want a bit more performance?
