so far i know is RS-27 a modified H-1,
Chamber Pressure: 40.00 bar rised to 48 bar
this increase thrust and ISP compare to H-1
and Gasgenerator output is used to feed gimballed verniers for roll control.
A Sound of Thunder: The Rise of the Soviet Superbooster
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Chamber Pressure: 40.00 bar rised to 48 bar
this increase thrust and ISP compare to H-1
and Gasgenerator output is used to feed gimballed verniers for roll control.
I don't think you are correct about that given the version of the partial notes from Upship, which I noted from googling you cite verbatim in full yourself here. If you have something that disagrees with this or has more detail, I'd love to have it, because it's been very hard over the years to dig up more than just people citing this specific blog posts' text.
In all three cases the engine was disassembled and damaged parts swapped from the sound of it, with at least some cleaning on a piece-part level. Arguing about specific test procedures from 60+ years ago isn't totally productive, but at least some of this reporting is available unlike any data on engine tests from much more recent projects on dunking engines within the last year or three.
SSME wasn't fully disassembled, just removed from the orbiter for inspection off the vehicle, and the Block II engines implemented in the late 90s were capable of ten flights on the vehicle, something demonstrated fully in testing (e.g. the AR-22 engine test sequence of ten firings in ten days).
One SSME flew 19 times on Space Shuttle
A record broken with Starlink launch on 23 February 2024
Not only flew the booster B1061 for the 19th times, one of Merlin Engines made it 22th flight !
A record broken with Starlink launch on 23 February 2024
Not only flew the booster B1061 for the 19th times, one of Merlin Engines made it 22th flight !
Sorry I wasn't clear but I meant every other engine tested in that program. It WAS a test program so of course they were going to tear down and rebuild the engine, seeing what (if any) damage was done by the salt water and time factors was a part of the program.
Why? Falcon 9 takes anywhere from 14 to 21 days for just the postflight refurbishment. Engine and stage refurbishment for the proposed recovered Saturn 1/1B booster was estimated about the same.
At the beginning of the flights yes, after all you're doing major inspections on all equipment since it was somewhat of a 'test' article under "real world" stress. SpaceX did the same when they ramped up reuse.
Not as much as you might think, keep in mind that both the S1 stage and the H1 were pretty 'over-built' for the time.
Most launcher and engines are, that comes pretty naturally when you figure in test firings and such. The ironic thing is the original idea for recovering the Saturn 1 stage was to save money and be able to test reusability but ARPA (who was sponsoring the work on a big booster) was hesitant to spend the money needed to develop a full recovery system. Note that SpaceX pulls the engines for examination and then refurbishment in pretty much the same way the SSME was for later Shuttle program use.
Doesn't seem to be much needed as it was all part of the process they used.
And as noted the jury is still out on if it's actually economical or practical for the current and projected flight rate. Keep in mind that the current high flight rate of Falcon is more due to internal (StarLink) launches than external.
None that I know of are quite that bad
Recovery in a booster stage will always cost some payload, (currently about 15% for the Falcon 9) but there are ways to improve that such as upper stage propellant choices or things like SRB's and booster assist systems.
Recovery requirements pretty much require large changes, especially if you started out as an expendable design. (Like Falcon 9 had to have major changes to accommodate reuse) It's always going to be a question of economics and design.
And eventually the SSME did achieve minimum refurbishment between flights
As noted the RS-27 was based on the H1 engine design being essentially an H1 with manufacturing and performance 'tweaks' that were available with more modern technology and materials. The RS-27A and RS-56 was where major changes were being done. Actually leading the "RS-X" proposal of the 90s.
As noted they managed this with the SSME and it's what SpaceX does with the Falcon 9 engines. They pull them for maintenance and inspection and pull some refurbished ones from storage if needed to meet the next flight goal.
Randy
I don’t think there’s any magic answer to Hermes, what you listed were still fundamentally the goals of our Hermes (except military use, which were only studied at concept level, the French Armed Forces were already too busy with the ill-fated SAMROS then Helios in the 80s for anything like a military Hermes), yes you could slightly relax requirement of payload to orbit, Downmass, offloading requirement to Freedom and MTFF, no EVA... but there really is no magical solution that can prevent Hermes from being a long, costly and hard 10 years development from the point where production begins (a point which wasn’t reached IRL, with flights planned in the early 2000s) by companies which had no experience in either spaceplanes, crewed spacecraft or even reentry vehicles or cargo spacecraft..
I do think that Hermes is slightly overrated compared to contemporary or similar spaceplanes, even from a technical point of view !
HOPE at least went to a full structural prototype, and would benefit from latter reentry and drop test experiments, MAKS May never have had the funding for it, but it had also had a structural prototype (both tanks and airframe, as well as a working subscale prototype of its main engine and proven orbital engine), benefited from the huge Contemporary experience of Buran’s maker molnya. They may not be as sexy as Hermes, but these two projects were arguably more technically sound than Hermes! Sometime when people talk about Hermes they make it sounds like it was as advanced as say, the Dyna-soar... bulls***, Hermes was closer to the SLI Orbital Space Plane than the Dyna Soar.
And again, that’s not talking about the organisational and political point of view. So yeah, IMO the only way to make Hermes happen is to fundamentally change its entire context, both political organisational and technical.
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Why they use glider ?
Since 1960s under ELDO were plans for Glider launch by Europa IV rocket.
CNES study next Hermes also under SOLARIS for manned capsule.
So far i know, CNES favour Hermes for landing on runway, either a launch site or in France.
because French Navy were unable to do recovery operation for manned capsule in ocean during that time.
Did not know that, from what i read (wikipedia mostly in this specific case) the engines were rebuilt each flight, but in hindsight that is probably just the early engines
S-1 was a monster of tanks, i doubt it could land in the ocean without sustaining damage (unlike Titan which had to get sunk by the Navy a few times)
All this makes me question NASA's fisical responibility, considering this led nowhere, same with J-2 derivatives
Its still business, given that the constellation idea is catching on means that it works, though it needs to get regulated as multiple countries want the same, and due to it being LEO it means that we might hit 10000 LEO satellites quickly
In Falcon 9's case it was grown and modified for more lift over time, by the time Falcon Heavy was ready the payloads Heavy was designed for early on were launched on Falcon 9, which is why it took a while for Falcon Heavy to get more launches
Given that the vast majority are on paper it must be uneconomical to fly reusable stuff
Nowadays we use better materials then the 60s, that testing has little bearing on the RS-27 or RS-56 due to the different materials and alloy's used, not to mention the computer systems wiring installed and other stuff that would get wrecked
In your own words the H-1 was completely dismantled and cleaned and HAD PARTS REPLACED, this is not similar to NASA and SpaceX doing inspections (without complete teardown) on SSME and Merlin
The technology, alloys and stuff would make the engines different, expecially if the 56 gets made
Basically it sounds like the French were wanting it to be a french thing that flys ESA astronauts, while ESA wanted a ESA launcher
Given French involvment in all levels the astronaut roster would be prioritized for french astronauts, which would politically divide the other countries who might have an issue with using their tax dollars to fly another countries astronaut, unlike the US or Soviet Union where this wasn't an issue
It would never have flown, given the small size of the design its not suprising the weight became an issue, unlike Shuttle where the growth wasn't as much of an issue (remided easier)
The vast majority of all rockets ever designed were only on paper, so it's not a surprise that the vast majority of reusable rockets ever designed are also on paper, too.
yes it exactly happen like this, since France was building Ariane rocket for ESA.
That also the reason with Hermes escalated, from simple glider to Mini space shuttle with cargo bay until 1985.
once the Russian offered Soyuz seats to ESA , the Europan Manned Spacecraft Program was dead...
currently offer now SpaceX seats or even entire crew Dragon for paying customer like: NASA, Inspiration4, AXIOM, ESA.
Ya, what i meant was that, the reusable designs wern't economical to develop in the first place due to high development costs and penatlies for weight
with the rest of designs it varies on practicality, Saturn Derivatives were too expensive with only limited use (NASA) as DoD wasn't interested, Modular Nova was a pipe dream
besides everybody has an idea, and 1 percent of those ideas are put on paper, while 99.999 percent of them don't see hardware made
Like Atlas V Heavy, it could work, just that the payloads heavy enough to need it flew on Delta-IV Heavy
To me it sounds like each side wanted to get the minority in costs while having the priority France wanting ESA to pay for part of it, while maintaining French Dominance, ESA wanted a European manned ship but with the costs shared with France
They wanted a cargo bay for various reasons, mostly bringing stuff to the Free Flyer, its late game redesigns that cost the most in weight, as you need to redesign a shitload but want to preserve completed work, it was such a small design and thats why weight was an issue
given ESA is by definition a international space coalition (or cooperative space alliance/coalition) cost splitting would always be wierd, some countries would want the goodies (payload space and astronaut seats) for little cost.
There are hundreds if not thousands of never-funded or funded-to-study-and-never-built LVs out there. RLVs aren't special in 99% of them never being built, and high development cost isn't special to RLVs either.
What i was first referring to was reusable derivatives for FLOWN hardware, like Winged Atlas, the multitude of S-1C reuse ideas, the Space Shuttle reusable flyback LRB's and many, many other idea's
And specificially how uneconomical said conversions were for these rockets, on this site we tend to act like old concepts could work without a hitch and that obscure designs could have saved space travel etc. Randy's resusable H-1 has issues but has little bearing on the Delta II's RS-27 due to different materials, technology and techniques, and the reusable Saturn 1 stage would be a bitch to work on due to the clustered tank design
I know the hugely vast majority of launch vehicles are not built, same with planes and cars and and trillions of other things
Congrats my friend! Well well deserved, so happy to see this wonderful timeline get such positive recognition.
after fiasco of Europa Rocket and death of ELDO
France start the Ariane Project with 60% finance (40 % by Germany) under CNES and french companies using European parts
with success of Ariane 1-4, was France the only provider for Launch system to ESA in 1980s . (Italy Vega rocket and Russian Soyuz came much later)
ESA wanted bigger rocket for 1990s, CNES a launch vehicle for Manned mini Shuttle, so both came to agreement.
but Hermes ran into problems and got chancel in 1990s, while Ariane 5 got build and used until 2023...
There's a fascinating new piece from RussianSpaceWeb about the planned public announcement of the N-1/Groza system if it were successful:
I'm not sure if nixonhead was aware of these documents when he wrote the ITTL press release, but in any case he nailed it- the announcement of Zond 9 as a "research satellite" for "deep space science" is almost verbatim what the Soviets were planning to announce in OTL.