Pappystein

HA! I already put standard Agena on top of MX It is a great LKO (well LEO now that I am using KSRSS 2.5) small sat launcher with a low cost. BUT in all seriousness, the MX especially but even Castor 120 would have a hard time lifting a useful payload with a 1.5m Agena Evo. I find myself equipping boosters to the first stage when launching an Ascent Agena Bus satellite. MX has a high Acceleration for the first half of the 1st stage but the 2nd half is much lower by comparison and it is easier to get to less than 1:1 TWR with Agena on top.

Are you using a scale other than 0.64?

Sorry just edited my post further Yes it would be another custom diameter... or it could be Shrunk down to 1.5m. I am not proposing it be made for KSP to be clear. Just stating that is where the varying lengths come from for Agena Evo

there was a 105" diameter Version and a 118" Diameter version. The 105" was longer... that would be about... 1.70m or 1.75m KSP scale I *THINK* (2.667m IRL) ***Folow-up Edit*** The 105" I believe was meant for a new launcher or a potential Thor based launcher (it is just a little bigger than the Thor's 8ft diameter) Sort of a replacement for Thorad? Not much is mentioned in the Shuttle Agena documents I have other than it was quickly eliminated as it did not gain an appreciable cargo volume in the shuttle bay (the payload would be almost as constrained in length as an Ascent Agena derived Shuttle Agena. Conversely the 118" version was significantly shorter as to provide a much larger length of payload capability in a shuttle bay. In all the documents I have. WITH THE EXCEPTION of AGENA-C, I have never seen a document quote a different length for the 118" Agena Evo (the stage is titled "Evolutionary Agena" in every document... Agena Evo is just easier to say and NOT "BIG" or "FAT" since both of those were used by other companies on other products.) Agena C was never built, and beyond preliminary design of the tank, never actually designed. LSMC was trying to sell it instead of fix the problems with Agena A and B. The problem with Agena A and B was one of space in the GCU... This was fixed with the Analog-Digital GCU on Agena D. Agena C was a way for LSMC to get more volume in the GCU without an appreciable loss in performance. In the Agena NRO documents I acquired from the NRO for public release website, I found two references to the Agena C... one was a memo on why it was such a bad idea to reward Lockheed with another contract when they were not meeting production goals **Even with alternative fuel loads** (my emphasis.) Unsure what they meant... could be same tank with two different "fill levels" or it could be two different alternative fuels... or two completely different tanks (size and all.) The only thing known is the Agena C was to be a greater diameter and shorter length than Agena B. Agena C could have been 105" or it could have been 118-120". Just don't know with what I remember. Said documents are so poorly reproduced that I get a headache just trying to read one page.... So I haven't re-read them in a while. Also the 1974 Agena documents point out a 8" tank extension to allow for new fuel (MMH + HDA (AKA IRFNA-IV in Community Resources) .) Also noteworthy is the change to a more modern Aluminum Alloy... But back to Agena Evo, all the NASA documents on wide body Shuttle Agena from 1972 clearly state the 118" diameter version is the preferred option. The 1974 documents throw the SOT drop tank Agena into the mix and that is the preferred option with a future growth to a mostly Different Wide body Agena.

Ha! My current wallpaper on my Laptop was my Angry Alligator I snapped a year ago or so!

Love the Flag. *FACEPALM* I am sitting on some other Big Agena Documents. ***EDIT, they are from the same series of reports*** Drawings are post Ascent Agena , but I also have some information on the proposed (and immediately ignored for GOOD REASONS) Agena C that LSM/LMS proposed to the USAF in lieu of fixing Agena A and B (Hence the GOOD REASONS) Fat Agena was basically MORPHED/CANCELED into the Bus for the KH-9 Hexagon (it isn't a true 1.875KSPm Agena but it is a direct technological, engineering and continuity descendant.)

I have had SO MANY issues with these mods over the years (all the way back to the OG KJR by Ferram) that I just quit using them and have blanket stated that if I am using BDB, or any of the NearFuture part sets... ESP if I have Robotics or Docking ports. HARD PASS. I get that KJR in any form is easier than manually selecting all the "auto-struts" (what a bad name for that FWIW!) but the Auto Struts never break my Builds. KJR ALWAYS messes up for me. Everyone's mileage may vary but this has been over enough years that I just have to say no now.

https://i.imgur.com/9zFlpJI.png Hmm. Well I TRIED to react to it!

Zorg has already answered this but I thought I would throw this out as an opinion. IF you are only building "real" rockets then something like realFuels (any) or RO are great. However if you are going for "Lego-ability," which I am pretty certain BDB was built around, then you might be better off using BDB+Nertea's Cryotanks+ the Hypergolic BDB patch that is in the Extras (Shameless plug since I made it with significant help from Jso!) You get Hydrolox, Methalox, AZ50/NTO and standard LFO. Sure you are not using MMH+NTO or UDMH+WFNA but you are in the correct ballpark with these options. The reason I lean this way is because that is what most Rockets are. A series of interchangeable or semi-interchangeable parts. (Looking at you Saturn A and B series... Saturn Atlas Centaur go!) In the end, you have to do what you want/need,. Again, this is just my opinion as a player and Historian (and not a member of the BDB team!)

Likely the B3 (XLR-119) then. Also thanks for the link to the full document (Archived now) Never going to get rid of the rage... Internet makes things too easy to make things up some times. And that is really my biggest problem. I know I am not perfect (I almost exclusively write from memory instead of reading each and every document every time I write something.) But at least I try to keep on the correct point. As I already stated, didn't read the last page of posts and spent two hours trying to NOT sound like the Angry Armchair NASA Historian! As an Asside, I think that is the most comprehensive review of the development of the S-IV stage I have done without getting into the technical minutia.... Might have to expand that into a new Historical article!

The Question has already been answered... and I promise I won't try to growl this time with my response (it isn't you Galileo Chiu... it is the question and what causes everyone to ask it that I get angry about all the time.) So TL:DR Version: Direct Apollo was a Proof of concept to prove that DIRECT FLIGHTS WERE BAD! not just bad but REALLY OUTRAGEOUSLY STUPIDLY BAD! Long Version: The SUPPOSED Saturn C-8... is a study done as part of the Saturn C-2 and C-3 programs (and it is well documented in the 1960 documents.) It was a case study to show why Tinker-Toy, or more modernly LEGO, construction in Orbit was Cheaper and QUICKER. IE it would not have been until about 1971-72 that An Apollo Direct could have landed on the moon. That time line does not include time for any delays. The unknowns in Earth Orbit Construction vs the long Delay caused by a Direct rocket prompted the LOR decision which could be done on time and safer than either Direct or EOR/Tinker-Toy. For point of reference the Plan in until Early 1961 was to launch multiple Saturn Rockets with inline docking S-IVB stages. These S-IVB stages would be powered by a Slush-fuel Liquid Hydrogen and LOX. The stage was latter designated S-IVC when the idea was re-visited for the Eros and Mars flyby missions. Several of these stages (If I recall correctly 4) would fire off in series to launch a fully equipped Apollo Capsule and lander combination... (the Capsule was to land on the Moon.) Saturn S-IV stage sidetrack: About the time of the Apollo MLV program (1967-1969) a NASA document (Houston not MSFC) re-issued a drawing of the C-2 era Direct Apollo rocket and labeled it Saturn C-8. The document in question was part of a packet sent to the US Congress for information on alternative rockets to Saturn in the Post Lunar phase. Then in Nova 3rd Generation (yes there were THREE NOVA Programs!) someone threw said "Saturn Direct" study in and again labeled it as Saturn C-8. I can find no documents that Von Braun or MSFC actually submitted this idea. This is all followed up by modern internet sloppy documentation and miss-quoting by Astronautix doing another Great job of posting things without proper documentation and no real-world facts to stand on.... And then Astronautix quoting Wikipedia as a source when Wikipedia quotes Astronautix as a source... (it happens on many but not all of the Titan and Saturn Pages) There are three reasons the re-submitted Apollo direct does not make sense: Nova3G was supposed to be BIGGER than anything in the Saturn Structure of rockets could lift. I GUESS if you surrounded the Direct Apollo Saturn with 6x AJ-260s you MIGHT get ALMOST enough payload to orbit.... The Mission had changed but the stages stay the same... Not conducive to big lift to either Low orbit or escape trajectories Congress (and NASA!) wanted NEW technology... there was nothing NEW about Apollo Direct Ascent. It used Saturn Avionics, Engines, and structural design just made larger ad-nauseam Point 3 is the biggest sticking point to the whole argument that Apollo Direct Ascent was EVER meant to fly. ADA or renamed Saturn C-8 is the litmus test as to if a proposal is worthy of looking into or not for big Lunar or Interplanetary rockets. Nothing else. As an aside... when did Tinker toys go from all wood to all plastic?! I guess I should read all the posts before Writing a Novel answer eh? Impressed! What parts and engines did you end up using?

Your question has already been answered but no one explained why. The simple answer is Hydrolox is both Lighter and more efficient, if the BDB Team were to convert the Hydrolox stages to LFO, the rocket those tanks and engines were designed for would be too heavy to fly following the rules of Stock (part mass and engine thrust both about 25% of real.)

Sort-of. The AJ-260 is too short to reach the upper interestage of the S-IC stage... and the 3x AJ-260 would burn to long making the S-IC stage nearly superfluous. So instead, they used the 2x AJ-260 length (the long length we have in BDB) and added an addendum LFO tank on top of it to create the structural connection to the structural top of the S-IC... and provide a little more fuel and thus burn time to the S-IC stage.

Flown any P-40 Warhawks or A-10 Thunderbolt ][s recently Zorg? ***SO SHARKY*** Ugh! ***NOT Sharky!*** Seriously Thanks for the Decals!

A) I still can't believe this is a project that is being undertaken it looks amazing and I know you probably feel it is just over half done! B) Have an odd-ball but hopefully an easy request. Any chance of 6.25, and 4.25m Heat shields for Recoverable Saturn stages? I am tempted to just create re-scales of either the Gemini or Big-G Heat shields but thought I would put this up on the "part potential Radar" as potential quick and easy part fodder. (gosh I hope those would be quick and easy!) I know this has already been specifically answered... it is your Life Support mod. All Life Support mods seem to think "ADD A TON OF MASS" = Good Life Support (I haven't found one that DIDN'T add a crap ton of mass that was already on the base spaceship parts.) I stopped using LS mods because every one of them breaks the game balance in a NEGATIVE way (ok yeah that is my opinion.) In fictional craft you may not see this... But in historically accurate ones... that are modeled as close to realism as the BDB team shoots for.... Well you can clearly see the problem.

Sorry I actually meant SPS and the Mini Service Module... too many xPSes in Apollo!

Fair Enough. I guess I am a big TR201 fan for that SM so anything else is either BIG, SILVER or WHITE

So what, 6 seconds of Fuel with 4 J-2 engines? The APS engine looks SOO out of place on the Orbital small SM.... Thanks for the screen shots!

While this is an interesting drawing. The Centaur C (latter re-designated Centaur E) depicted as the landing stage could handle the mass (remember it was NOT A balloon tank Centaur!) But Boil-off would not allow this to be viable. The Lunar Take Off stage APPEARS to be either 2x AJ10s or 2x XLR-81s. Potentially this could have been 2x Hydrolox fueled engines but I doubt that. And while I doubt Centaur could have been used as depicted... It is a pretty awesome set of drawings! I forgot to ask yesterday, Are you making the Aft docking Tug for the S-IVC? I shared those drawings a few months ago when I first found the S-IVC documents (it might have been the same document you got these drawings from I don't remember)

****REAL S-IVC NOISES!**** Also @CobaltWolf Might have a Simple solution for the Slush Hydrogen that is part of this stage... Just bump LH2 up to a 16: or 17: ratio instead of the normal 15: ratio. Gives longer time on orbit before boiloff... No need for additional engine switches on the LH2 engines Also this would be about the perfect length to work with the S-IV mount and RL10s... As an Alternative to the real S-IV

The S-I 8x mount with only 2 active nodes? SHRUG never saw or used it myself. I did in the old parts days have an "Extras" version of the S-IC engine mount that allowed you to place 2,3,4,or 5 engines as you choose (it was a very minor tweak to the stock settings.) Some real(ish) rockets like C-2 would greatly improve with their proper shorter tank lengths. Just a matter if CobaltWolf and co want to put the effort in I guess. Of course it would be fun to see the Cluster S-II stage at some juncture too! (I kid I kid!)

From this angle I thought so too. When you are at Low altitude however it is WAY overpowering!

Just be glad I don't have RMM installed right now (WHY DON'T I!?!) It would have been LTBE powered and fueled by CH4! AKA the "Titan V" as I call it!

My next (and probably final one) is going to be LDC Titan based!

So I decided to do the Challenge as issued by CobaltWolf earlier multiple ways. I have already posted the Saturn II INT-18 derived launcher I used to get to the Moon KSRSS 2.5x. I am just building to get 9.5 to 10K dV with a good TWR for all soup bound stages (in atmosphere!) Saturn C-2 "Modernized" STAGE 0: 4x TU-122/M-55 boosters from the extras folder (they use the Algol model as it is ABOUT the exact same size if not the right shape at all!) STAGE 1: Ground Lit Saturn S-I stage stretched to the inital 2.1xm. But with only 90% fuel (to match the reduced fuel capacity of the Saturn C-2's First stage vs Saturn C-1's First stage!) STAGE 2: utilizing the S-IVB tankage stretched with the +4.5M extension. 4 engine "S-II" engine mount from the S-IVB engine plate. 4x RL20P-3 Vacuum engines STAGE 3: utilizing the S-IVB tankage stretched with the +3m extension, 1 Engine S-IVB base plate with a single RL20P-3 (2 engines got me there faster at a lower efficency) PAYLOAD (as required by Cobalt in OG Post!) Is that the "Man in the Machine!???"