Here is a two stage design optimized for escape payloads that is powered by six RD-180s and four RL-60s. I'm sizing these to match or beat SLS Block 1. Notice how much shorter the RD-180 rocket is compared to the F-1B rocket, though I think that a real second stage of this mass would likely end up longer with a smaller LOX tank. Similar results can be achieved with the proposed "AJ-26-500" engine. - Ed Kyle
And it's a little off topic I suppose, but I've been wondering what an EELV class core with a single F-1B on it...maybe 5 or 6m wide...and a dual use upper stage with either a single or pair of RL/MB-60's would to to LEO, GTO, and escape.So if you are ever board and looking for something to do some time, I'd be curious about something like that.:-)
Quote from: Lobo on 10/17/2013 04:41 amAnd it's a little off topic I suppose, but I've been wondering what an EELV class core with a single F-1B on it...maybe 5 or 6m wide...and a dual use upper stage with either a single or pair of RL/MB-60's would to to LEO, GTO, and escape.So if you are ever board and looking for something to do some time, I'd be curious about something like that.:-)Well, for an EELV type vehicle, I suppose the easiest way would be stretching the Atlas V core to a similar TWR as the current one. The RD-180 has about 4.2 MN of thrust, the F-1B about 8 MN, so that's almost twice as much, allowing for a core stage that's also twice as big (could be bigger, but we want upgradeability for the upper stage).
A single F1 CCB, with a normal SEC can get an estimated 5.2 tons to GTO, or 12.8 tons to LEO. With a DEC, this is 14.6 tons to LEO. If the upper stage is also scaled up to twice it's mass, doubling total mass (little problem because of F1B's power), the rocket can get 18 tons to LEO, and 7.3 tons to GTO. With dual MB-60 instead of RL-10, the payload to LEO is increased further, to over 22 tons to LEO, without boosters!
When it gets really fun though, is when you create a Heavy variant. A 3x CCB variant with the new upper stage (which has specifications very similar to ACES) would get over 50 tons to LEO, and a 5x CCB variant gets over 75 tons to Low Earth Orbit!
How about making it out of a Delta IV core? I don't know that it would be any more modification than stretching an Atlas V core. Keep it 5m, and have different tank ratios. The overall core will probably be shorter, but it'd actually look pretty similar to a Delta IV. Then replace the RL-10 on the 5m DCSS with an RL/MB-60 (which was the original plan anyway with the 5m DCSS when Boeing-Rocketdyen and MHI developed the MB-60).
With the better PMF, a single CCB+Upgraded DCSS would get about 19 tons into LEO (surprisingly high, to be honest). With GEM solid rocket boosters from Delta, it would go up to 21 tons with 2x GEM, 23 tons with 4x GEM, 25 tons with 6x GEM and 27 tons with 8x GEM. I think the high mass of the Kerolox core waters down the performance increase GEMs provide.
With the ACES-like upper stage I described earlier, payload for the base rocket would go up to 34 tons to LEO, and 11.5 tons BEO. If the mass for a single RL-60 from astronautix.com (500 kg) is accurate, a single engine version of this stage would be able to push 11 tons BEO (the mass savings from an extra engine would likely be bigger though, but I don't know by how much).
A Heavy variant with this dual engine upper stage would be able to push up to 54 tons into LEO, and a Super Heavy variant would be able to bring over 80 metric tons to LEO! I don't know how much GEM's would add up to this though, that will take some more time to calculate. If I can remember it, I'll put it here.
Oh, and a single core with 2x 5-segment SRBs can get almost 50 tons into LEO. But now I'm just playing around.
That is all nice but the RS-25, RL-10 and SRB already exist (more or less) and the RS-25 is a cool engine that deserves to be preserved (as well as all the hydrolox people working at Aerojet Rocketdyne).
Quote from: edkyle99 on 10/17/2013 02:36 pmHere is a two stage design optimized for escape payloads that is powered by six RD-180s and four RL-60s. I'm sizing these to match or beat SLS Block 1. Notice how much shorter the RD-180 rocket is compared to the F-1B rocket, though I think that a real second stage of this mass would likely end up longer with a smaller LOX tank. Similar results can be achieved with the proposed "AJ-26-500" engine. - Ed KyleIf you used the ICPS as a third stage, could you replicate Saturn V's escape performance (~45 tonnes IIRC, same as SLS Block 2) with a 4x F-1B first stage?
Even without RS-25, wouldnt' those hydrolox people still be building RS-68's for Delta IV?
RL-60 and MB-60's were both mostly develop already by 2005
assuming RD-180's or F-1B's would be cheaper than RS-25E's to develop and produce
And no need for "advanced boosters" in the future.
F-1B is a 8MN engine and a redesign from the F-1 which last flew 40 years ago. All the people who worked on it are either dead or retired. How could it possibly be cheaper?
What were the estimates for RS-25E? $700m development and $40m a piece? My gut feeling tells me F-1B won't beat either of that, Jim said size matters .
The 5 seg. will run out but why not start manufacturing them again in 10 years instead of pushing another multi billion dollar booster development program? (let alone a core redesign).
^I guess the 4xF1B Block 1 version of yours is hard to beat. Not so sure about Block 2.Problem is, SLS will be canceled anyway, would you rather end up with a bunch of RS-25E or F1B?
Block IIB with advanced boosters and DUUS will likely not require a core redesign.
F1B. I'd rather be stuck with a powerful engine that could be useful both for EELV-class vehicles and SHLVs, than with a niche sustainer engine. It's just too expensive to be mass-produced.