If to dream up, it is possible to think up something similar. On the first stage there are 4 RD-171M engines or eight RD-180.
I am not an expert mathematician, but there are geniuses on the site. If Russians built an S-IC stage, would modern weight saving techniques and RD-180 better specific impulse mean five RD-180s would suffice to achieve the same performance as original S-IC?
Do we have an idea of how much time and money it would cost to bring the RD-171 back into production?
As far as we know, production RD-171M isn't stopped yet. It will be much more difficult to restore production RD0120. However according to the available information about 80% of production equipment for RD0120 are kept.
Quote from: Dmitry_V_home on 12/12/2015 06:12 pmAs far as we know, production RD-171M isn't stopped yet. It will be much more difficult to restore production RD0120. However according to the available information about 80% of production equipment for RD0120 are kept.I was under the impression no more Zenit hardware is being manufactured.
Perhaps, but RD-180 and RD-191 are in production, and it would be relatively trivial to create a modernized RD-17X based on the RD-180/191.
Quote from: Александр Гвидевич on 12/12/2015 07:26 amI am not an expert mathematician, but there are geniuses on the site. If Russians built an S-IC stage, would modern weight saving techniques and RD-180 better specific impulse mean five RD-180s would suffice to achieve the same performance as original S-IC?Russia wouldn't have to build an S-IC if it was able to exploit it and the USSRs earlier LH2/LOX engine developments. The key would be reviving RD-0120 for second stage propulsion. RD-0146, being developed for Angara, could then be clustered to power a third stage. These highly efficient upper stages would vastly reduce the size of the first stage compared to S-IC - it might gross half as much weight. The rocket might only need 12 RD-191 engines (or three RD-171M engines). The second stage would be maybe 25% bigger than Saturn V's S-II stage if powered by four RD-0129 engines (assuming they could be air-started). Here's one guesstimate model to put 45 tonnes to TLI. Mp/GLOWStage 1: 921/1001 tonnes 12xRD191 T=2,352 tonnes ISPavg = 328.3 secStage 2: 576/640 tonnes 4xRD-0120 T=800 tonnes ISP = 455 secStage 3: 101/115 tonnes 8xRD-0146 T=80 tonnes ISP = 461 secGLOW = 1806 tonnesPL = 45 tonnes LAS - 5 tonnesDeltaV = 12,500 m/sThis would be a beautiful, but very expensive, rocket. - Ed Kyle
I've heard that Energomash still does some work on RD-175 engine on their own dime, which is 1000 mt class engine - essentially a "jacked up" version of RD-171M. Maybe it will find some use in the future.
Quote from: Space Invaders on 12/13/2015 06:49 pmQuote from: Dmitry_V_home on 12/12/2015 06:12 pmAs far as we know, production RD-171M isn't stopped yet. It will be much more difficult to restore production RD0120. However according to the available information about 80% of production equipment for RD0120 are kept.I was under the impression no more Zenit hardware is being manufactured.Perhaps, but RD-180 and RD-191 are in production, and it would be relatively trivial to create a modernized RD-17X based on the RD-180/191.
Ed, KBKhA aslo designed HydroLOX RD-0150 with much bigger thrust than RD-0146, so there is no need for cluster of 8 engines on Stage III
It has already happened. The current Zenits have an RD-171M, which was a retrofit of the RD-180's improvements to the RD-171 that saved 300kg of dry mass. The RD-191 has some further improvements. It will be produced in Omsk, but for now, both Atlas V and Angara use engines built in-house by Energomash. So the manufacturing base capabilities will stay open at least to 2020. With ULA's move to Vulcan and Angara's production moved to Omsk, Energomash needs something by 2021/2 to keep the line busy.
Quote from: baldusi on 12/16/2015 04:31 pmIt has already happened. The current Zenits have an RD-171M, which was a retrofit of the RD-180's improvements to the RD-171 that saved 300kg of dry mass. The RD-191 has some further improvements. It will be produced in Omsk, but for now, both Atlas V and Angara use engines built in-house by Energomash. So the manufacturing base capabilities will stay open at least to 2020. With ULA's move to Vulcan and Angara's production moved to Omsk, Energomash needs something by 2021/2 to keep the line busy.Some large plants participate in production of the RD-191 engine: Metallist-Samara plant in Samara (chamber), the Voronezh mechanical plant in Voronezh (chamber), Proton-PM Plant in Perm (turbopump). Final assembly of the engine is conducted in "Energomash". In the future assembly of RD-191 it is planned to transfer in "Proton-PM".
It has already happened. The current Zenits have an RD-171M, which was a retrofit of the RD-180's improvements to the RD-171 that saved 300kg of dry mass.