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Project Alexandria: a history of spaceflight done in Real Solar System


Felbourn

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Greetings Kerbanauts! This is Kerbal Space Program, Project Alexandria: a history of spaceflight done in Real Solar System.

w0mVVwG.png

If you have facts you want to share about any craft I have launched, or that will eventually launch, feel free to share it all here and I will get it into my videos if I can!

Why is it called Project Alexandria? The Royal Library of Alexandria, or Ancient Library of Alexandria, in Alexandria, Egypt, was one of the largest and most significant libraries of the ancient world. It was an attempt to gather together all knowledge into one place. It was lost in a fire, so... all spaceflight history... fire... sounds right to me!

"Will you be doing mission _______ by county _______?"

You can answer this yourself. Ask these questions instead. Was it a major event? If so, yes I'll do it. When? Well... what year did it happen? I go chronologically.

"Are you going to do ___________? What will you do for _________ mission? What will you show?"

You'll have to wait and see! I don't want to spoil the surprise.

MODS

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Music

Intro - Our Story Begins

Outro - Carefree

 

Saved links for reference material:

Favored Links

General HistoryAstronautixSpace FirstsGunter'sVarious RocketsAwesome Rocket InteriorsBraeunigEvery Launch!Research DOCsNASA Technical Report Serverb14643, Johnathan, Launch Sites

 

Craft Links

Sputnik 1Various FactsVanguard 1Pioneer 1 wikiNASA Launch ArchivesPioneer 1 detailsLaunch PictureLR-79-7Thor FamilyThor-AbleThor StagesLarge Engines ChartThor picsb14643 Site MapNASA NSSDC Rocket ListPioneer 3braeunig AtlasVanguard InfoCornoa Missionsmore Cornoa InfoJuno Infomore Juno InfoLuna Infomore Luna InfoEarly Launch VideosEarth Images From OrbitAwesome Rocket InteriorsMercury & Gemini saved for laterVostokVostok ImageAnimals in SpaceVostokVostok AdaptationsSyncomX-15 Flight LogMariner 4Stage 1, Stage 2, Stage 3, IU, F-1 Engine, J-2 Engine, Stage Fuels, Internals, Mission WeightsFuels, NASA dataHistoryApollo 11LM Stage, LM Images, LM DataSpace ShuttleManualNASA InfoOMSNASA Database

 

Other References

Space Station RescueNASA LaunchersNASA picturesMoon Landing

Edited by Felbourn
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  • 2 weeks later...

After much discussion on the RSS thread...

http://forum.kerbalspaceprogram.com/threads/55145-0-25-Real-Solar-System-v8-2-1-Oct-22-14?p=1556718&viewfull=1#post1556718

I kept researching, and a dozen sources and web sites later... I believe it might be closer to this:

stage wet    dry  isp	dV
1 29064 4979 265 4587
2 625 375 220 1102
3 165 97 220 1151
4 37 14 235 2222

total = 9061

Interesting find in all of it, while googling "baby sergeant juno 1":

"Each Baby Sergeant solid-fueled motor was 46 inches long by 6 inches wide. Each of the second and third stage Baby Sergeant motors burned 50 pounds of T17-E2 solid fuel. The fourth stage Baby Sergeant motor burned 50 pounds of JPL-532A solid fuel, a slightly more efficient fuel than that burned in the second and third stages."

The T17-E2 solid fuel was 220 IspV and JPL-532A was 235 IspV. It is uncertain if this claim was true for stages 2 and 3, or just stage 2. If stage 3 was also more efficient then we're 9139 dV overall. Also, I might have the IspV wrong for these. What if T17-E2 was 235 and JPL-532A was >235?

Also of note, the difference of 2 kg on stage 4 is the different between 9061 and 9311, so chances are the values are really close but any discrepancy is from lack of perfection or incorrect stage reporting by these web sites.

Morale of the story: There's a lot of room for error.

Various pages I have open at the moment:

http://en.wikipedia.org/wiki/Explorer_1

http://en.wikipedia.org/wiki/Juno_I

http://en.wikipedia.org/wiki/MGM-29_Sergeant

http://www.unexplained-mysteries.com/forum/index.php?showtopic=144671

http://www.enterprisemission.com/Von_Braun2.htm

http://www.spaceline.org/rocketsum/jupiter-c.html

http://www.daviddarling.info/encyclopedia/J/Jupiter_rocket.html

http://www.designation-systems.net/dusrm/app4/juno.html

http://www.astronautix.com/craft/exporera.htm

http://www.astronautix.com/astros/vonbraun.htm

Edited by Felbourn
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Very interesting find on the propellant differences for Baby Sergeant! I'm afraid I don't know the answer to the question, but judging by Explorer 1's SMA, it might well be that it's 235 and >235; I have my doubts that 9061 is enough for 358x2550.

Is there a similar NASA book to Vanguard: An Engineering Summary?

Note that by the time you get to Mercury-Redstone you're going to hit this again, since I've had an *awful* time figuring out what the performance of the non-Hydyne Redstone engine is...

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Very interesting find on the propellant differences for Baby Sergeant! I'm afraid I don't know the answer to the question, but judging by Explorer 1's SMA, it might well be that it's 235 and >235; I have my doubts that 9061 is enough for 358x2550.

Is there a similar NASA book to Vanguard: An Engineering Summary?

Note that by the time you get to Mercury-Redstone you're going to hit this again, since I've had an *awful* time figuring out what the performance of the non-Hydyne Redstone engine is...

The wiki and a few other pages say the Isp for stage 2 was 220, but stage 3 was 235.

http://en.wikipedia.org/wiki/Jupiter-C

Still doing a little Explorer 1 research here and there. I noticed the wikis and the RO mod agree Isp 265 and thrust 416180 N. Doesn't that mean the flow rate was ~160 kg per second? And MANY sources say the engine burned for 155 seconds. That's 24814 kg of fuel unless it was designed to auto-throttle at higher altitude. I have not read anything about it throttling back. BUT... various web pages also state the fuel carried was ~24000 kg. Unless the engine throttled, we're off by ~800 kg. The extra could account for my issue with the dV.

From: http://history.nasa.gov/sputnik/expinfo.html

Overall (takeoff) 64,000 10,260

Stage 1: 62,700 / 9,600

Stage 2: 1,020 / 490

Stage 3: 280 / 140

Stage 4: 80 / 31.5

Stage 1

64000 takeoff

9600+1020+280+80 = 10980

64000 - 10980 = 53020

53020 lb = 24050 kg

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It's worse than that: in real life you have to deal with propellant residuals, wherein not all the propellant in the stage gets burned (eventually, no matter how high your acceleration, you'll start sucking pressurant and you'll flame out even thought there's a bit of propellant somewhere in the tank). That's on the order of 0.5% for first stages.

I agree with your mass, coming up ~300kg short. That said, 64,000lb sounds like a suspiciously round number. (I get 300kg difference by checking astronautix's Jupiter C stage info, where total propellant is 24,540kg leaving a deficit of 300kg vs the rated 155*416.18/265/9.80665 = 24.823t.)

Only thing I can think of is that the burn time includes spinup time for the turbopumps, so they weren't pumping full blast right from the start

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It's worse than that: in real life you have to deal with propellant residuals, wherein not all the propellant in the stage gets burned (eventually, no matter how high your acceleration, you'll start sucking pressurant and you'll flame out even thought there's a bit of propellant somewhere in the tank). That's on the order of 0.5% for first stages.

I agree with your mass, coming up ~300kg short. That said, 64,000lb sounds like a suspiciously round number. (I get 300kg difference by checking astronautix's Jupiter C stage info, where total propellant is 24,540kg leaving a deficit of 300kg vs the rated 155*416.18/265/9.80665 = 24.823t.)

Only thing I can think of is that the burn time includes spinup time for the turbopumps, so they weren't pumping full blast right from the start

That makes sense... it's only off by 5 seconds of fuel usage even with my numbers.

I also have been finding it suspicious that it was exactly 64000 lb on every site/page. I have been inclined to fudge some numbers to make it all more accurate based on other factors like the burn time vs. efficiency and so on.

Strange how this can be fun. I know some people think I'm crazy or too meticulous, but I'm in the line of work I'm in* because this is who I am. :)

*professional game programmer and technical game designer -- department head

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The wiki and a few other pages say the Isp for stage 2 was 220, but stage 3 was 235.

http://en.wikipedia.org/wiki/Jupiter-C

Still doing a little Explorer 1 research here and there. I noticed the wikis and the RO mod agree Isp 265 and thrust 416180 N. Doesn't that mean the flow rate was ~160 kg per second? And MANY sources say the engine burned for 155 seconds. That's 24814 kg of fuel unless it was designed to auto-throttle at higher altitude. I have not read anything about it throttling back. BUT... various web pages also state the fuel carried was ~24000 kg. Unless the engine throttled, we're off by ~800 kg. The extra could account for my issue with the dV.

From: http://history.nasa.gov/sputnik/expinfo.html

Overall (takeoff) 64,000 10,260

Stage 1: 62,700 / 9,600

Stage 2: 1,020 / 490

Stage 3: 280 / 140

Stage 4: 80 / 31.5

Stage 1

64000 takeoff

9600+1020+280+80 = 10980

64000 - 10980 = 53020

53020 lb = 24050 kg

Getting the mass flow from isp and thrust is a good way to get little mistakes creeping in. See, the thing is none of those are constants during a burn, especially in atmosphere and doubly so with solids. Even the best designed solid with a perfectly constant flat thrust profile (good luck with designing that) would have a "combustion chamber" that dramatically changes dimensions as the "walls" get burned away (they are the propellant, after all). Pressure and temperature thus vary during the burn (even in liquids due to thermal transients), affecting the final engine instantaneous isp. Quoted isps are a crude engineering average, a much better measure of a rocket is the impulse (J) you get out of it (the integral of Fdt). With that and mass values, you work out isps assuming J=F*t, which is only true if F is constant... which it's not. But close enough for government work.

So in order to replicate RL, you'd be better off adjusting the isp so you get the same burn time at the required thrust to achieve the target delta-v. You will end up more accurate if you got your masses right.

Edit:

Gotta love the old Semyorka. It may have been kind of crap as a weapon (other than the fear factor, which was great BTW), but the other day one of it's great-great-grandchildren put three guys on ISS! I gather that's the one that carried uphill the world's most illustrious radio beacon?

Rune. Does KSP allow long decimal isps?

Edited by Rune
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Isps are floats, so you get ~7 digits of precision. And yeah, you're absolutely right about solids. Plus, even the total impulse is an estimate, since solids have the disturbing habit of chucking out unburnt chunks of fuel...

Felbourn: consider my appetite whetted. :)

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Isps are floats, so you get ~7 digits of precision. And yeah, you're absolutely right about solids. Plus, even the total impulse is an estimate, since solids have the disturbing habit of chucking out unburnt chunks of fuel...

Felbourn: consider my appetite whetted. :)

Almost ready for Monday...

EuINC86.png

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Episode 2: Sputnik to Vanguard

I knew it, "world's most illustrious radio beacon"! Nice episode, BTW :) Loving the lesson in history (even though I learned almost nothing new other than Explorer's solid upper stage configuration). And I finally get how you are filling the runway with the history of rocketry... You are going to have to weld the models for static exposition soon :P

Rune. A rocket geek's dream!

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I knew it, "world's most illustrious radio beacon"! Nice episode, BTW :) Loving the lesson in history (even though I learned almost nothing new other than Explorer's solid upper stage configuration). And I finally get how you are filling the runway with the history of rocketry... You are going to have to weld the models for static exposition soon :P

Rune. A rocket geek's dream!

I tried to weld for THIS episode but the welder goes absolutely insane when I try on the complete craft for that.

It might work better if I break each one into the individual launchers. I think there may be issues with procedural fairings and such though.

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Great second episode indeed. One question, do you use a specular or normal map for your tanks on the Vanguard? They look very cool, kinda metallic. Couldn't find anything on Github.

The config was not specifically in the Vanguard folder. Here you go: https://github.com/Felbourn/History/blob/master/GameData/History/textures.cfg

I'll try to remember to add the textures themselves to the repo.

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