[1.12.5] Bluedog Design Bureau - Stockalike Saturn, Apollo, and more! (v1.14.0 "металл" 30/Sep/2024)

[AdrianDogmeat]

15 hours ago, Blufor878 said:

Possibly, mine are derived from the Saturn C3 proposals from back in the day. Just thought the idea of a 3-engine Saturn derivative was pretty neat. What about yours?

Mine's a 5m scaled core/upper stage with STMEs instead of F1s

[Blufor878]

On 5/8/2023 at 4:25 PM, DaveyJ576 said:

SATURN IB REPLACEMENT?

For the record, I want to state that I really like the Saturn IB. It is one of the coolest rockets ever, and iconic to boot. The IB and it's older brother the Saturn I hold a special place in U.S. rocket history and for good reason. However...

It was not optimal. No respectable rocket engineer () would deliberately design a rocket with clustered tanks.  No less than Werner Von Braun himself once testified before a Congressional committee that it was an engineering compromise, and if conditions had been different, it would not have been built that way. Its whole reason for being was to get a large powerful launcher built as quickly and cheaply as possible, hence the concept of using tank construction based on existing smaller designs and clustering them together. The biggest drawback is greatly increased weight, with reduced performance when compared to a comparable mono-tank design.

In most reasonably realistic alternate history scenarios, the existence of the Saturn IB is a given. So the real question is, assuming that some sort of Apollo/Saturn/Skylab program continued beyond what historically happened, what do you do for a follow-on medium lift, man rated rocket? 12 complete Saturn IB vehicles had been built under the original contract, so when all of these had been used what do you do then?  It makes little sense to continue to produce what is essentially an engineering kludge. Making the assumption that financial concerns would continue to dominate any post-Apollo planning, I would like to present what I consider to be the best option available to NASA in the late 1960's and early 1970's. It is none other than the Saturn INT-20, which I will refer to as the Saturn III.

Specifically, the three F-1 engine variant (hence the name Saturn III) that could put 78,000 lbs. (35,380 kg) into a 185 km orbit. This is roughly twice the payload of the last version of the Saturn IB, eliminating a huge gap in capability. The four and five engine variants are overpowered and would require the shutting down of multiple F-1 engines before staging, requiring that you haul dead weight uphill. This rocket has several distinct advantages over other Saturn variants for the LEO mission:

1. No new hardware needs to be developed. Everything already exists.
2. No new engine development is needed.
3. No heavy and time-consuming modifications to the S-IC are needed to accommodate solid or liquid boosters.
4. The only changes to the S-IC are removing equipment like engine plumbing, and external fairings, and blanking off engine openings.
5. Some software revisions would be necessary but would be minimal. Some aerodynamic testing would be required, but would also be minimal.
6. Changes to the MLP are minimal, requiring only the removal of unnecessary hold-downs and piping.
7. The single biggest change would be shortening the LUT, but this simply requires removing some arms and removing the S-II section. Yes, I know that is more complicated than I have made it sound, but no new hardware needs to be developed.
8. The ability to haul hefty payloads (i.e. LM Lab or Skylab resupply modules) in the SLA, along with a full Block 2 CSM (still short fueled) is now possible.
9. From start of the project to first flight would probably be about one year. The pacing item would be the work to shorten the LUT.

The prime contenders for a competitor to the Saturn III are the INT-19, aka Saturn II (S-II + S-IVB plus solid boosters) and the Saturn IB-C or IB-D (Saturn IB with Minuteman or Titan solid boosters). These rockets would have violated most, if not all of the points listed above. Specifically, any of these alternatives would have required substantial and expensive changes to the launch mount/MLP and the LUT to accommodate the solid boosters, and an extensive reworking of the basic airframe in order to handle the side loads imparted on the first stage by the boosters. You also accept all of the negative performance and safety issues of using SRBs with a manned launcher.

So that is my case for the Saturn III as a mid-1970s replacement for the Saturn IB. I like the Eyes Turned Skyward Saturn IC, but it would have required an extensive R&D program with new stages, new GSE and launch pads, and new spacecraft. I think the Saturn III is more realistic given the political and financial environment facing NASA in the 1970s. And it looks cool!  Saturn III is a handy and versatile launcher and I flew the below mission with it.

First stage uphill flight, staging, and second stage push to orbit.

  Reveal hidden contents

Pitch down to hit orbital parameters, and stable orbit at 250km.

  Hide contents

Payload extraction and orbital operations.

  Hide contents

This flight uses what I call the Block 2B CSM. It uses the five man CM, along with a Tweakscaled roll out Gigantor solar array in the otherwise empty SIM bay. The LM Lab has a lot of greebles on it, and is intended for Earth observations. I flew four crew on this mission, pilot, engineer, & two scientists. I did fly a J-2S on the 2nd stage and standard F-1's on the first stage. If I upgraded to F-1A's my payload capacity increases. I used MechJeb PVG to a 250 km orbit. 2.5x KSRSS Earth. Upon SECO I had roughly 8% fuel remaining in the S-IVB. Max acceleration was 3.2 Gs, well within real life tolerances. It flew like a dream.

It is so cool to be able to fly these type of hypothetical missions with BDB. I would like to extend my personal thanks to @CobaltWolfand the entire dev team for all of the hard work.

 

13 hours ago, DaveyJ576 said:

See my post on page 1187 for a rundown on my “Saturn III”.

Good stuff. I was actually reading on INT-20 just recently. Apparently they make instructions to build your own using the Lego Saturn V set. Might make this in KSP myself (with BDB, not legos, the latter would be more difficult). 

Also that LM lab build is gorgeous.

[BorfoandShnogs]

On 1/30/2024 at 7:00 PM, Blufor878 said:

Decided to work on Skylab Block II a bit more. First, a visit from Soyuz!

Also, JARVIS gives us MORE POWER!!!

I really like what you did with your Skylab! but I have a question regarding your Soyuz spacecraft. Where did you get the extra parts for it? (The thruster cover on the back, and the piping on the reentry capsule). And where did you get the thermal insulation material "paintjob" for it? Thanks in advance!

[Blufor878]

8 minutes ago, BorfoandShnogs said:

I really like what you did with your Skylab! but I have a question regarding your Soyuz spacecraft. Where did you get the extra parts for it? (The thruster cover on the back, and the piping on the reentry capsule). And where did you get the thermal insulation material "paintjob" for it? Thanks in advance!

Thanks, and Tantares just got an update a few weeks back. @Beale's slowly phasing out some of the old Soyuz parts for these new ones with updated textures.

Also I made INT-20 with a twist. I forgot which Saturn proposal made use of it. But I read somewhere that the SIVB was supposed to get a new engine, the HG-3. That never came to pass, but continued HG-3 development did lead to another famous engine...



Not sure if there is an equivalent to the HG-3 in BDB. If there is please let me know. In any case I figured I'd go full ham with the RS-25.

[Blufor878]

58 minutes ago, Blufor878 said:

Thanks, and Tantares just got an update a few weeks back. @Beale's slowly phasing out some of the old Soyuz parts for these new ones with updated textures.

Also I made INT-20 with a twist. I forgot which Saturn proposal made use of it. But I read somewhere that the SIVB was supposed to get a new engine, the HG-3. That never came to pass, but continued HG-3 development did lead to another famous engine...



Not sure if there is an equivalent to the HG-3 in BDB. If there is please let me know. In any case I figured I'd go full ham with the RS-25.

Never mind, I MAY have answered my own question. Saturn V-3 using the "PL20" series engines.





With that said, if I'm wrong again, I'd love feedback (please don't hurt me).

[Pappystein]

21 hours ago, Blufor878 said:

Thanks, and Tantares just got an update a few weeks back. @Beale's slowly phasing out some of the old Soyuz parts for these new ones with updated textures.

Also I made INT-20 with a twist. I forgot which Saturn proposal made use of it. But I read somewhere that the SIVB was supposed to get a new engine, the HG-3. That never came to pass, but continued HG-3 development did lead to another famous engine...



Not sure if there is an equivalent to the HG-3 in BDB. If there is please let me know. In any case I figured I'd go full ham with the RS-25.

HG-3 did not exist... it was a HYPOTHETICAL PLACEHOLDER so NASA and industry engineers could build around it's expected performance.     Best in BDB is the RL20 and the XLR129.  

 

Also sorry everyone, been sick so no Ch3 of Agena posted yet...   It takes me about an hour and a half to post each chapter and I just haven't had the energy.

 

 

[Blufor878]

11 hours ago, Pappystein said:

HG-3 did not exist... it was a HYPOTHETICAL PLACEHOLDER so NASA and industry engineers could build around it's expected performance.     Best in BDB is the RL20 and the XLR129.  

 

Also sorry everyone, been sick so no Ch3 of Agena posted yet...   It takes me about an hour and a half to post each chapter and I just haven't had the energy.

 

 

That makes sense. In that case, what are the PL20 engines based on? Also are the XLR129 listed under a different name. I want to try this later.

[TaintedLion]

14 hours ago, Pappystein said:

Also sorry everyone, been sick so no Ch3 of Agena posted yet

Will there be any information about the Agena-2000 that was planned for the Atlas 5 Light?

[Pappystein]

6 hours ago, TaintedLion said:

Will there be any information about the Agena-2000 that was planned for the Atlas 5 Light?

That is in a separate Agena Hypothetical article....   Sadly, there isn't a huge amount of info other than it had NOTHING to do with Agena, and it was just a "It is in the news it is being retired so a good name to use..."  Kinda like Atlas itself

9 hours ago, Blufor878 said:

That makes sense. In that case, what are the PL20 engines based on? Also are the XLR129 listed under a different name. I want to try this later.

I use Real names patch in the BDB Extra folders... so I only know the real names off the top of my head... not the BDB-ified names

**BUT** going through the files it is the PXR-129

Sorry missed the first part of the question... the RL20 WAS a developmental engine that sometimes falls under the HG-3 name that is floated arround.   It isn't a HG-3 since that was an internal name from Rocketdyne as I recall, but it is the same performance category.   Zorg has the facts on that (I don't have the refrences he does for the RL20)

 

 

Edited February 3 by Pappystein

[Pappystein]

Agena Chapter 3

Chapter 3:   Wright Field, The Missile Pod and Pied Piper:

Spoiler

During the Earth Satellite program, both USAF Western Division (ICBM) and USAF Wright Field were involved in the process.  This is one of the few times that Wright Field was directly involved with a space-based program.   Until about this point, Wright Field was THE experimental and design headquarters for the US Army Air Corp and later the USAF.   Starting in the late 1940s, however, the move to what would become Edwards Air Force Base was begun, and Wright Field was feeling the “pull” of jobs and projects away from the original home of the US Army Air Corp experimental and design center.    Wright Field was responsible for the B-58’s Rocket Pod program, meaning it is here in the Earth Satellite program that an alternative to the AJ10 exists.   The alternative is the Bell Aircraft Corporation XLR81.  Now Bell is hungry for a contract.  They have an engine that has just lost its only function, but it is a perfectly workable and usable engine.  At this same time, Aerojet is working its collective tail off, trying to meet all the contract requirements for Titan, Able, Project Phoenix, Large SRM… etc.  This means that Aerojet did not have the engineering capacity to also work on a gimbaled version of their AJ10 at the time.  Mind you, gimballing for the AJ10 would come soon, but not soon enough for the design process undertaken for Pied Piper.   Bell was willing to put the effort in and modify their existing engine to meet new requirements quickly and at only a small expense.   The engine bell was slightly extended from the original design, gimballing hardware was designed, and investigations into better fuel for space were begun.   All in the span of a few weeks.   Bell knew their engine might be a winner in space, so they were working on all these problems even before the Earth Satellite program with their own funds, according to one telephone conversation log.

Pied Piper Pioneer becomes Agena A. 

While the original payload envisioned in Pied Piper was never built, Agena would become synonymous with the latter Keyhole / Corona / SAMOS programs.  Agena A combines the Bell XLR81 engine in its Bell Engine Company’s 8001 and, after two flights, 8048 versions.   The 8001 is a space-rated prototype based on the original Hustler Rocket Pod engine, still using JP-4 as fuel and having a short bell with a 15:1 expansion ratio.    8048 switched to the Hypergolic combination of UDMH for fuel and the same IRFNA-3 nitric acid for oxidizer as 8001.   The bell on 8048 grew to a 20:1 bell, and the weight savings by using Hypergolic fuel meant the engine barely gained any weight.  The savings in mass vs a JP4 powered stage were due to denser fuel, which is heavier per unit volume.   This allowed a smaller Rocket stage to be built with the same over all performance.   Also unlike JP4, UDMH withstood the rigors of the cold of space better, but not perfectly.    

The Avionics was, at best, crude on the Agena A.   Each mission had to have a custom-made Avionics structure and component list.   The avionics combined into the Guidance Control Unit or GCU was at the top directly below the Payload fairing.  Between it and the fuel tank was the so-called Forward rack, which was, on some missions, an empty void in the space-frame.   For other missions, it was crammed with parts of the GCU, or used for small experiments.   This forward rack would see the biggest changes from Agena to Agena as to what was in it or invading its space.   The forward rack was open to the bottom side of the GCU, allowing the GCU direct access to this space.   Some documents call the avionics on Agena the Telemetry Response Unit (TRU), and others the Guidance Control Unit (GCU.)  For standardization, this series of articles uses the term GCU as this is an important distinction for later USAF Agena programs.

Each Agena A’s GCU was hand-built depending on the mission flight profile, duration, altitude it was to fly, and attitude of the Agena stage itself.   The attitude control seems to be where most of the changes from mission to mission happened on the GCU.   This was because computers, in a small compact form, did not economically or numerically exist in 1957.  Each flight had a unique profile that would require different modules to be added or removed from the GCU to provide a unique to the mission list of timed commands or a list of orders picked and sent by ground control.   In the initial Pied Piper plans, the GCU would have extended from the fuel tank into the PLF.   Early in the design process, it was realized that the GCU invading the payload envelop significantly reduced payload potential.  To solve this engineering issue, a structure, the previously mentioned Forward Rack was added between the fuel tank and the GCU.  

So, the structure of the Agena was cast in basic form by the Agena A.  From Nose to tail;

• Payload Bay, under one of the various Payload fairings
• Guidance and Control Unit (GCU)
• Forward Rack (alternatively Forward Bay)
• Fuel and Oxidizer tanks, Moncoque structures, thicker but similar to balloon tanks with the same thickness structural skirt between them.
• Aft Rack, which is a skirt-like affair around the Engine
• Bell LR81 Rocket Engine of various marks.

 

 Ch1:

Ch2:

 

 

[Pappystein]

Agena Chapter 4:    EXTRA!!!   EXTRA!!!   Agena Kills Vega!

Spoiler

Chapter 4,  First Intermission:  Agena and Vega

As seen in the previous chapter, Via three different projects, two groups created the original RAND Corporation dream of a space satellite launcher.   Pied Piper, or latter as it would be named Agena, was not the only upper stage satellite launcher or satellite in development.   Ramo Woodbridge or, more correctly, Thompson Ramo Woodbridge (AKA TRW) worked in conjunction with Convair to develop a quicker, “cheaper” alternative to the DARPA pie in the sky Centaur high energy upper stage.   Vega, which I plan to cover in more detail in a future document, was designed as a quick and dirty re-use of Centaur design steps on a Kerolox stage.   Vega would also combine with the proposed Juno IVB’s upper stage to be the apparent stage for the early 1960s space exploration.    As stated in the previous chapter Pied Piper come Agena A was a grey program.  Meaning it was not well known outside of the USAF/CIA itself.   Now, what you are about to read is mostly my opinion based on the following few facts.  

• NASA was COMPETING with the USAF for space in 1959.
• The USAF was rapidly losing trust in Convair General Dynamics
• The USAF was still trying to bully other organizations out of their perceived territory
• The USAF felt they were the only organization capable of handling anything with the word flight in it.

The USAF (and the so-called Military Industrial Complex) did not want civilian agencies involved in what they felt was “their turf.”   The USAF wanted full control over its contractors and did not like to share said control with a civilian agency that might harm the USAF’s manifest destiny.   In short, the USAF, just over 10 years old, defended its “territory” with zealous rancor.   Anyone trying to enter the USAF’s area of “expertise” was harangued, harassed, or made to look like they did not belong.   Damn the torpedoes, full speed ahead, was the attitude that I perceive of that time.    Many readers may feel this is an unfair portrayal of the early USAF.   I give you a simple proof of this attitude with things like the Admiral's Revolt, Fixed-wing aircraft in the US Army, to name two easy to read up on examples of where my opinion comes from.   The USAF is a fantastic organization. Once they found their place under a civilian government in the late 1950s and early 1960s, it became the spear that it is today in the United State’s arsenal of democracy.  But sadly, we are talking about those same 1950s and early 1960s when the US Government had to use more rod and less carrot with the USAF… the US Army… and to a lesser extent, the US Navy… and even with NASA!

Enter Agena and Vega.   Vega, a Product of Convair who has not been pleasing the USAF recently with early Atlas failures, the F-102 Delta Dagger debacle, the equally bad F7Y Sea Dart, and R3Y Tradewind debacle for the US Navy….   Well, the USAF did not want Convair’s engineers to spread thinner than needed.   While the USAF is responsible for starting the Vega program as a quicker extension of the long-term Centaur program, the Vega program was seen as expendable, duplicative, and unnecessary in light of things like Juno IVB and Agena.   This expendability was because the USAF already had Agena on the books, and while the Vega had better performance, the USAF did not think they needed it at this time, and they were wrong.  The issue was that Vega was partially cryogenic with its liquid oxygen oxidizer.   People may tell you LOX won’t boil off rapidly.  Sure, in comparison to Liquid Hydrogen LOX does not boil off all that fast.  But it sure boils off enough to not last for more than a few orbits in space.   It may be easier to prevent said boiloff than with Liquid Hydrogen, but you cannot stop it.   This un-reliability in orbit is why the USAF thought the Agena had more potential.   The Agena, in its final production form, could lift less than Vega to orbit.  But it could continuously re-boost said payload if still attached.   Something the Vega could not do.   The LOX would boil off in a matter of days, turning gaseous and potentially rupturing the tanks.  Of course, by adding the TRW Juno IVB upper stage to the Vega, you had a storable fuel final stage.   In the USAF’s mind, this made a bad job worse because the Juno IVB upper stage was tiny and had a small 6000lb thrust engine.   USAF fighter and bomber pilot mentality at the time was “go fast or go home.”   See the XB-70 Valkyrie, B-58 Hustler, F-104 Starfighter, F-106 Delta Dart, and YF-12A Blackbird for good examples of this idea!    So, we can thank the USAF for not wanting someone else to manage a space program.  Remember, the USAF was the final decision maker on every NASA-purchased Thor, Atlas, or Titan Rocket and every Agena, Able, or Ablestar stage.  You could even blame the USAF for Thor-Delta becoming just Delta and leading to that fun naming convention for NASA, as the USAF was not in charge of it!   Of the main rockets listed above, only at the Titan 3E do we see the USAF step back away from much of the design decisions for a NASA production rocket.  Finally, the USAF was ready to let someone else play in their patch of sky.  Yes, you can see I have a LOT of opinions on the USAF seeking control of space.    Now, what is the point of all this opinion?   In 1958-1960, while still early in the development of both Vega and Centaur, the USAF offered NASA their new Agena Rocket.   It would be cheaper and ready earlier than Vega (by a few months.)   Of course, we all know the drawbacks of NASA choosing Agena over their preferred Vega.

• Small diameter means smaller physically sized payloads. While the TRW stage was tiny, the base Vega could lift Centaur-sized items into space
• USAF still has control of Agena where as NASA had control of Vega
• No control of price spiral (Contracts were directly LOCKED to whatever the USAF agreed to pay)
• Little say in the development of new versions (until Shuttle Agena in the 1970s)
  
   

But NASA was new and, to be perfectly frank was having budget and leadership issues from the get-go.  Honestly, any new organization has these issues, so that is not so surprising.  Something else to consider is that NASA did not want to rock the boat and wanted a civil discourse, at least in public.  In private, with access to their own records, we know NASA also was a bit big-headed then, and we can see some of that today, Boeing Starliner… oops, sorry, not sorry!  Sacrificing Vega for the sake of not rocking the boat was probably the right decision in the short term for NASA.  But it left the long term open for many problems, including Agena not meeting NASA's needs.    No one seems to have seriously considered combining the Vega first stage with the Agena as an upper stage.   But then again, the large-size payload fairings (PLF) technology was not really perfected until the early 1970s.  And it was in fact the Payload fairing issue itself that partially lead to the demise of Vega.

Vega Drawings (simplified) from NTRS server report 19730065945  Vega Final Report

The table is from Quest Magazine 9:4 from 2002, appearing on page 48 (Author Joel Powell.)  

Vega alone has a calculated Delta V of 633 based on numbers from a two-page excerpt called "Atlas Vega Technical Diagram,"  dated 16 October 1959.

Agena B, with mass data from Encyclopedia Astronautica for empty mass, calculates to 612 Delta V using the same math.
(https://strout.net/info/science/delta-v/)

Vega Interface diameter:  60" or 120".

Agena Interface Diameter 65".

 

 

Shortly After Vega's cancellation, the remaining funds for Vega went into developing a "Kick Stage" for Centaur.  It was never built.  However, some of the interesting concepts were recycled and re-issued as Centaur Jr.

 

Edited February 4 by Pappystein
Fixed missing table and final paragrap

[Zorg]

On 2/4/2024 at 2:50 AM, Pappystein said:

That is in a separate Agena Hypothetical article....   Sadly, there isn't a huge amount of info other than it had NOTHING to do with Agena, and it was just a "It is in the news it is being retired so a good name to use..."  Kinda like Atlas itself

I use Real names patch in the BDB Extra folders... so I only know the real names off the top of my head... not the BDB-ified names

**BUT** going through the files it is the PXR-129

Sorry missed the first part of the question... the RL20 WAS a developmental engine that sometimes falls under the HG-3 name that is floated arround.   It isn't a HG-3 since that was an internal name from Rocketdyne as I recall, but it is the same performance category.   Zorg has the facts on that (I don't have the refrences he does for the RL20)

 

 

HG-3 was a NASA designation and the main public reference available has NASA contracting out P&W not Rocketdyne to perform a study of what the future of rocket engine development should be. Though its possible Rocketdyne also participated in some aspect of the study I've found no first hand source for that, we do know at the time they were doing a lot of aerospike and J2 nozzle studies. The timing of the study seems to be between the RL-20 and XLR-129. The study mostly concludes staged combustion is good and doesnt have any real designs associated with it but the RL-20 is a good analogue for that notional engine as like the HG-3 (as conceptualised) could be a drop in replacement for the J-2.

I wrote down everything I found out here:

 

On 2/3/2024 at 5:49 PM, Blufor878 said:

That makes sense. In that case, what are the PL20 engines based on? Also are the XLR129 listed under a different name. I want to try this later.

You can find more background on the RL-20 specifically in the link above too. The best reference online was Alternate wars but thats down now so I just have a few images and (maybe PDFs) saved from there lying around. But that post summarizes everything.

[Pappystein]

9 hours ago, Zorg said:

HG-3 was a NASA designation and the main public reference available has NASA contracting out P&W not Rocketdyne to perform a study of what the future of rocket engine development should be. Though its possible Rocketdyne also participated in some aspect of the study I've found no first hand source for that, we do know at the time they were doing a lot of aerospike and J2 nozzle studies. The timing of the study seems to be between the RL-20 and XLR-129. The study mostly concludes staged combustion is good and doesnt have any real designs associated with it but the RL-20 is a good analogue for that notional engine as like the HG-3 (as conceptualised) could be a drop in replacement for the J-2.

I wrote down everything I found out here:

 

You can find more background on the RL-20 specifically in the link above too. The best reference online was Alternate wars but thats down now so I just have a few images and (maybe PDFs) saved from there lying around. But that post summarizes everything.

http://www.generalstaff.org/Space/Space.htmhttp://www.generalstaff.org/Space/Space.htm   <<<----  New location for the Alternate Wars/BBOW pages you are referring to Zorg (this is the main space page)   It is slowly being updated with the missing content like you are refering to... IIRC Achive.org has some good backups of the old Alternatewars.com/BBOW page (if I am remembering the URL correctly)

 

Sadly some of the files are archived on archive.org and the rest are not

 

 

Edited February 7 by Pappystein

[Zorg]

11 hours ago, Pappystein said:

http://www.generalstaff.org/Space/Space.htmhttp://www.generalstaff.org/Space/Space.htm   <<<----  New location for the Alternate Wars/BBOW pages you are referring to Zorg (this is the main space page)   It is slowly being updated with the missing content like you are refering to... IIRC Achive.org has some good backups of the old Alternatewars.com/BBOW page (if I am remembering the URL correctly)

 

Sadly some of the files are archived on archive.org and the rest are not

 

 

Oh the engine pages werent there last time I checked, hope it gets uploaded at some point. But yeah archive.org was able to recover most of the pages on the old site I think.

[Pappystein]

Hmm... I may be a Dumb idiot...

 

NASA HG-3 designation:     Hydrogen Generation 3???      That was the Third Generation of Hydrolox Rocket engines

 

[Pappystein]

Agena Chapter 6:   What? You thought we were done with Pied Piper?

Spoiler

Chapter 6 Pied Piper Advance AKA Agena B:

Lockheed took their Pied Piper advance proposal and applied the new Bell Aircraft XLR81 rocket engine to it.   The larger tank size and heavier mass meant the XLR81 needed both an increase in ISP thrust and improvement to take advantage of Pied Piper's changes fully.   Enter the 8081 or USAF designated XLR81-BA-7 engine.  Increasing the bell's size to a 45:1 expansion ratio, the 8081 gained a needed bump in thrust from 67kn for the earlier Agena A engine to 71kn on the Agena B.   The key improvements were in ISP efficiency and restart in orbit capability, for a total of 3 ignitions, including at stage separation.

Like the Agena A, the Agena B would have a hand-built GCU that would oftentimes occupy the Forward rack.   In the Agena B, the forward rack was longer than on the Agena A for additional GCU modules that were never installed as far as can be ascertained.   The Agena B would use the same electrical supply batteries as the Agena A, and like the Agena A, most of them were mounted in or on the Aft rack that surrounded the engine combustion chamber.   Beyond the forward rack changes, the fuel tank and the engine, Agena B and Agena A were broadly similar.    Because of its extra fuel and the ability to restart the main engine, payloads attached to the Agena B could stay in orbit for much longer.  As much as 90 days, verse less than 20 for the Agena A payloads.   While intended to be the Standard Agena, the Agena B was a limited-run spacecraft due to the complex and constant need to alter the GCU.    While eventually an interim type, Agena B would set the standards that all later Agenas would be judged by.

Chapter 7:   The Most Hypothetical of the Hypothetical Agenas:

While Agena A and Agena B fought to meet the USAF and NASA's needs, many failed due to low-quality control.  Partly, this was to blame on Bell Engines, but the bulk of the blame rested right on Lockheed MSC's shoulders.   At this time, Lockheed MSC dared to propose a new Vega-sized Agena, the Agena C. Features a 10ft maximum diameter and approximately a 7ft overall tank length.  The Agena C, designed for the next generation of Spy and Communication satellites, was to keep Agena competitive with future growth needs.    If built, the Agena C would have been more than capable of managing even the final production form of the KH-9 Hexagon…  Well, with some small modifications.   Of course, the USAF laughed this proposal right out of the office and into the circular file.   While there are plenty of references to the Agena C proposal, no document has ever turned up covering its specifications.  We only know it was a 10ft diameter Agena.   Even the tank length suggested above is a suggestion.    What we do know is a few small fragments taken from many second-tier sources, none of which originate at Lockheed, NASA or the USA.

• Would use one or two un-named Bell XLR81 variant engines (source dependent)
• 10ft diameter (and compatible with Centaur interstage and hookups?!)
• It would have fit as a drop-in replacement for Vega.
• Higher orbital payload capability than all other upper stages built or planned at the time except Centaur.
• Proposed as either a USAF only (black) or USAF/NACA-NASA Joint program (Grey) Project
• Battery capacity to allow 30 days on orbit using existing loads.   Extendable with Solar or SNAP
• Restartable in-flight via either many cartridges or bellows, like GATV

Each and every one of those “facts” can be called into question because none of them originate from a first-tier provider (eg Lockheed archives, USAF archives etc.)   So, at best, the information is questionable.  Realistically, it is downright ignorable.   Sadly, Agena C appears to be a short trip to what happens when you, the manufacturer, think it is more important to deliver a new product when you do not currently have a fully functional product you have already sold.   In short, the USAF told Lockheed to “get it together.”   Agena C was destroyed before it was born.   Instead, the USAF contracted for a completely new, partially digital GCU for the upcoming 2^nd standard Agena, the Agena D.   More will be discussed on a forthcoming article of Hypothetical Agenas.

 

Spoiler

SUPRISE 2 Chapters!  (they are small)

Link to the previous chapter!

[Pappystein]

For those that haven't already noticed this... I am not covering the Payloads of Agena in this history of Agena development.   That is in part because they would each need their own article.  Also, while those payloads have been covered in many ways over the years, the actual development of the Agena is still less apparent to the average person... Hence, my focus is on the Agena itself.  

I do not plan to cover any of the payloads in great detail in the future either...  So if someone wants to go down the reaserch-n-publish rabbithole on one or more of the Agena payloads... feel free to!

[AliceChristina]

[AliceChristina]

[Zorg]

Work on Atlas continues at a slow pace. But it is continuing.

GSE cutouts and more details on Atlas A and D skirts

idk if I posted this before but the standard aft tank

A new aft tank just for Atlas SLV-3X "Fatlas" so the H1-D can actually fit on it properly (you need to rotate it 45 degrees though.

And a preview of the new tank setup thats been planned.

The annotation here isnt comprehensive. For example Atlas H MSD would be a base tank + SLV3C (&D) cylindrical extension + Atlas H conical adapter.

An SLV-3A would be base tank +SLV 3A extension+ 0.9375m conical extension etc.

Edited February 9 by Zorg

[hugoraider]

3 hours ago, AliceChristina said:

Wait a minute... where did you get the mint colored Soyuz?

[Kerb24]

47 minutes ago, hugoraider said:

mint colored Soyuz

It's available in the newest version of Intercolor.

[hugoraider]

Oh nice! Thanks!

[Pappystein]

20 hours ago, Zorg said:

And a preview of the new tank setup thats been planned.

The annotation here isnt comprehensive. For example Atlas H MSD would be a base tank + SLV3C (&D) cylindrical extension + Atlas H conical adapter.

An SLV-3A would be base tank +SLV 3A extension+ 0.9375m conical extension etc.

Impressive Work Zorg!

[DaveyJ576]

20 hours ago, Zorg said:

Work on Atlas continues at a slow pace. But it is continuing.

GSE cutouts and more details on Atlas A and D skirts

idk if I posted this before but the standard aft tank

A new aft tank just for Atlas SLV-3X "Fatlas" so the H1-D can actually fit on it properly (you need to rotate it 45 degrees though.

And a preview of the new tank setup thats been planned.

The annotation here isnt comprehensive. For example Atlas H MSD would be a base tank + SLV3C (&D) cylindrical extension + Atlas H conical adapter.

An SLV-3A would be base tank +SLV 3A extension+ 0.9375m conical extension etc.

I would give this a bunch of likes if I could. Thank you for making the effort. I really enjoy the historical aspect of BDB and this Atlas revision will immeasurably add to that. 

23 hours ago, AliceChristina said:

This is dangerously close to photograph like realism. Bravo! Your TUFX profiles are amazing.