Also, the corestage would have to be redesigned to tolerate the extreme thrust oscillation that 4x SRBs would generate. Even empty, the SRB segments weigh more than 100 tons each! Placing an extra 10x segments on the MLP, crawler and road would be intolerable.To draw a parallel for some folk: even empty the entire Apollo/Saturn V stack weighed less than 240 tons and about 2900 tons loaded. An SLS with 4x loaded SRBs would weigh far more than that before any propellants had even been loaded into the corestage!!
Quote from: MATTBLAK on 03/13/2012 06:29 pmAlso, the corestage would have to be redesigned to tolerate the extreme thrust oscillation that 4x SRBs would generate. Even empty, the SRB segments weigh more than 100 tons each! Placing an extra 10x segments on the MLP, crawler and road would be intolerable.To draw a parallel for some folk: even empty the entire Apollo/Saturn V stack weighed less than 240 tons and about 2900 tons loaded. An SLS with 4x loaded SRBs would weigh far more than that before any propellants had even been loaded into the corestage!!I see your point. The extra two 5 segment SRBs would add over 1200 extra tonnes of weight to the vehicle needed to be transported to the launch site. Another alternative would be to use a configuration similar to the design of Boeing's supper heavy concept by using three SLS LOX/LH2 core boosters. This would only add about 170 tonnes of extra inert weight to the launch vehicle needed to be transported to the launch site before fueling. Again, the advantage here would be that no new booster would have to be developed. Marcel F. Williams
That rocket doesn't work because SLS has an underpowered core.15 x SSME is very expensive and not much thrust.SLS is pretty much how to build a rocket without needing to develop new high thrust engines.
Regarding the tri-core CCB SLS, there would be a need for strong backs to support the weight. Also, isn't the T/W < 1? You'd have to half fill the tanks to achieve T/W > 1 and still throw away 15 RS25Es. Nobody's going to do that. The thing has to have either solid or RP-1 boosters for the initial high thrust. AJAX was a better design, but unfortunately too many politicians see NASA as pork for home, not a tool for science.
Quote from: Robotbeat on 03/13/2012 02:15 amQuote from: hydra9 on 03/13/2012 02:01 amIt would probably be cheaper for NASA to substantially increase the lifting capability of the SLS by just strapping on another pair of 5-segment SRBs. Plus if ATK successfully manages to get the Liberty concept going as a commercial crew launch vehicle then the 5-segement SRBs may come down in cost. Marcel F. WilliamsNew pad would be needed.And new crawlerway, and VAB floor, and crawler, and ML... four SRBs will be heavy.
Quote from: hydra9 on 03/13/2012 02:01 amIt would probably be cheaper for NASA to substantially increase the lifting capability of the SLS by just strapping on another pair of 5-segment SRBs. Plus if ATK successfully manages to get the Liberty concept going as a commercial crew launch vehicle then the 5-segement SRBs may come down in cost. Marcel F. WilliamsNew pad would be needed.
It would probably be cheaper for NASA to substantially increase the lifting capability of the SLS by just strapping on another pair of 5-segment SRBs. Plus if ATK successfully manages to get the Liberty concept going as a commercial crew launch vehicle then the 5-segement SRBs may come down in cost. Marcel F. Williams
PWR will compete with F-1A.
I think the best engine for a LRB would be to dust off the TR-107 from SLI as it was designed for this type of work.It also would be a cheap engine to manufacture due to it's simplicity.http://www.nasa.gov/centers/marshall/pdf/172380main_tr107.pdfhttp://www.astronautix.com/engines/tr107.htm
Quote from: Jason1701 on 03/14/2012 04:56 amPWR will compete with F-1A.I'm skeptical; do you have a source? Why would PWR resurrect the F-1 when they already have the RD-180?Edit: related thread: http://forum.nasaspaceflight.com/index.php?topic=24553.0 .
Quote from: deltaV on 03/14/2012 08:55 pmQuote from: Jason1701 on 03/14/2012 04:56 amPWR will compete with F-1A.I'm skeptical; do you have a source? Why would PWR resurrect the F-1 when they already have the RD-180?Edit: related thread: http://forum.nasaspaceflight.com/index.php?topic=24553.0 .1 F-1A produces the same thrust as roughly 3 RD-180s ?? Sounds like it might fit in the 5m booster structure as well. This is roughly the same effort as Aerojet taking the 50+ yr old NK-33 design to create the domestic AJ-26-500, right ? Both designs are basically the same age, and need to be updated to modern manufacturing technology. There also appears to be a supply of both legacy engines available, even though they would need some updates / re-certification before flying. At least the F-1 design documents were written in english.
Quote from: Jason1701 on 03/14/2012 04:56 amPWR will compete with F-1A.I'm skeptical; do you have a source? Why would PWR resurrect the F-1 when they already have the RD-180?
Source: talking to PWR. They prefer F-1A because it is American-made, which coincidentally means many more jobs for them.