Had another thought, and instead of swapping the US engine, I re-configured the 4 SRB segments into two 2-segment SRBs (taking the middle two segments out of the 4-segment SRB, which has been proposed by Thiokol and later ATK on a few occasions, and based on data should work fine) and strapped them to the side of the ESAS LV13 upper stage.Worked fine, lifting 26mT to the iSS>
Quote from: Downix on 05/16/2011 12:55 amHad another thought, and instead of swapping the US engine, I re-configured the 4 SRB segments into two 2-segment SRBs (taking the middle two segments out of the 4-segment SRB, which has been proposed by Thiokol and later ATK on a few occasions, and based on data should work fine) and strapped them to the side of the ESAS LV13 upper stage.Worked fine, lifting 26mT to the iSS>Stumpy Jr?
With what ISP? Did you assume a new optimised throat?
It looks....weird. Gnomish? I like it though, although I think that at this point building better fitting SRB's instead of shortening them to this degree might make a BIG diffirence in efficiency and perhaps safety.
Got to pondering a bit more, the twin 2-seg with a new core stage still seems off, it means more development for the program. Within the RAC-2 studies was one proposal which had Block I as the upper stage w/o the first stage, so, I did a bit of a switcharoo, and instead of developing an AIUS, I had the EDS developed, using the same 8.4m tooling at Michoud as the original plan, added the SRB support beam to the interstage, and viola, we have a core for our twin 2-seg SRB. To speed up development, I did not use the EDS's new insulation, instead utilizing the existing ET orange thermal protection, so the new insulation would need to be added into development later on. In addition, the tank is upside down, with the LOX to the front while for EDS it would be to the rear.This would have been ready to fly in 2008, requiring minimal development. This could loft up to 30.4 tonnes to the ISS. Once the J-2S+ engine was ready, the Block II program begins, substituting the J-2S+ for the SSME. This increases the payload to 36 tonnes to the ISS. When Ares V is ready, swap interstage with one not sporting the SRB support to lighten the load and use the new, non-popcorning insulation, but keep the existing design for crewed launch. Consolidation of manufacturing, tooling, and employees makes it more efficient an operation. This would have reduced the cost to develop the Ares V as well, with the EDS already being 80% completed, and enabled systems testing in the process. When the 5-segment design for SRB was completed, the 2-segment now becomes the 5-segment with the 3 middle pieces eliminated. It would have fulfilled the ESAS CLV requirements, taken less time and money, and have been ready for flight by the required date. No long poles, no costly up-front development, none of that.
Within the RAC-2 studies was one proposal which had Block I as the upper stage w/o the first stage, so, I did a bit of a switcharoo, and instead of developing an AIUS, I had the EDS developed, using the same 8.4m tooling at Michoud as the original plan, added the SRB support beam to the interstage, and viola, we have a core for our twin 2-seg SRB.
Quote from: Downix on 05/25/2011 05:55 pmWithin the RAC-2 studies was one proposal which had Block I as the upper stage w/o the first stage, so, I did a bit of a switcharoo, and instead of developing an AIUS, I had the EDS developed, using the same 8.4m tooling at Michoud as the original plan, added the SRB support beam to the interstage, and viola, we have a core for our twin 2-seg SRB.To confirm, this is with an air-start SSME?Very interesting config.cheers, Martin
Nope, ground start. When it switched to J-2X it would have then been air-start. That is why the performance jumped despite loosing both thrust and isp.
If you swap the O2 tank under the thrust beam it would lift the J2 without going to 3-segs.Cheers. Martin
Ok, proof I am completely bonkers. In a discussion about dead-ends, the discussion turned to the X-33, and I mentioned how I liked the Rockwell X-33 design due to how pragmatic it was in comparison to the selected Lockheed design. I them lamented how even then, it still could never be SSTO. Someone else in the group then popped up "If the point is to be re-usable, why not just re-use the Shuttle SRB? It's already re-usable." Which then got gears turning. The ESAS requirement for Ares I was a single SSME and a single 4-segment SRB, so I took the Rockwell X-33, with it's single SSME, cleaned it up for crewed flights, and strapped an SSME to the bottom. I then crunched the numbers through Schillings, and it would work as an orbital crew vehicle. It also avoids the pitfall which started the chain of failure with Ares I, that the SSME was too expensive to throw away, and too expensive to make air-startable. I took the X-33 and Platypus both (all 5 revisions of Platypus at that) and merged their lines with the existing shuttle systems. I even included an F-111 ejection module that seats 7.Stupid OCD, 5 hours of my life gone.
Looks like a scaled up X-37...
Quote from: Rocket Science on 05/31/2011 10:29 pmLooks like a scaled up X-37...A bit older, however. Here's Rev 3 of the Platypus IIRC
