The KSP Interstellar Proxima Centauri Challenge

[The-Doctor]

That's very impressive is that a mod? The von braun? 

[FreeThinker]

1 hour ago, pmborg said:

• I will use the "Kolonization" parts on "Von Broun" planet (target), I have a "Container Kit" with a "small factory"
• Inside that "Container Kit" is a big and mobile Factory, and after that I will create a House Colony to farm materials from drilling
• and then with those materials I plan to do the Colonization using the "Kolonization"

@FreeThinker,

If is possible, I would like to have your help/suggestions to reduce the weight on these parts in tones:

Any Idea? Specially the red ones.

Please note that the BigSphereTanks are empty

 

Well you might want to reconsider radial tanks, which are lighter and can be dropped when empty.

Btw, I releasd KSPIE 1.22.6 which includes another veraion of the Daedalus engine with cool exhaust effects (requires additional download of Far Future Mod)

Edited August 17, 2019 by FreeThinker

[pmborg]

7 minutes ago, FreeThinker said:

Well you might want to reconsider radial tanks, which are lighter and can be dropped when empty.

Btw, I releasd KSPIE 1.22.6

About "radial tanks" deftly I will try them, but that would change the all ship design/model, but yes if they are droppable I need to consider a try in that design.

About the new release I am still a big scary , the last one had a huge impact on so many mods that I had to revert back to previous, but sure I will try it

 

Edited August 17, 2019 by pmborg

[pmborg]

1 hour ago, The-Doctor said:

That's very impressive is that a mod? The von braun? 

Hello,

Please check this reply, page 3 with video:

https://forum.kerbalspaceprogram.com/index.php?/topic/143285-the-ksp-interstellar-proxima-centauri-challenge/page/3/&tab=comments#comment-3647894

is the CentauriDreams mod adapted to this Challenge.

Edited August 17, 2019 by pmborg

[The-Doctor]

Dusting out my old ssto opt craft files you may like, tho in testing it says missing parts, weird

My venture stars have 64 downloads on kerbal x  https://kerbalx.com/The-Doctor/KSS-Forward-Unto-Nebula

https://kerbalx.com/The-Doctor/MockingJay-FAR

 

 

 

 

Edited August 18, 2019 by The-Doctor

[FreeThinker]

@pmborg Notice in the latest release of KSPIE 1.22.8.4 I have made several changes relevant to the challange, I added persistant exhaust effect to all fusion egnines and fixed persistant thrust, which is quite important when you want to accelerate to a decent fraction of light speed without waiting a year.

Edited August 19, 2019 by FreeThinker

[pmborg]

3 hours ago, FreeThinker said:

@pmborg Notice in the latest release of KSPIE 1.22.8.4 I have made several changes relevant to the challange, I added persistant exhaust effect to all fusion egnines and fixed persistant thrust, which is quite important when you want to accelerate to a decent fraction of light speed without waiting a year.

Thank you so much I was waiting for those really nice exhaust effects

Still working hard on this challenge, is much more difficult than what it appears, because there is a variety of fine details, sometimes not visible in a picture that make all the difference to make all the missing to really work.

[FreeThinker]

@pmborg: I also modified the Bussard 2 to be more usefull as a replacement of the old bussard model

[FreeThinker]

32 minutes ago, pmborg said:

Thank you so much I was waiting for those really nice exhaust effects

Still working hard on this challenge, is much more difficult than what it appears, because there is a variety of fine details, sometimes not visible in a picture that make all the difference to make all the missing to really work.

notice there are 2 versions, the smaller version will create a much  larger exhaust, you also need to download Far Future Technologies mod to see the best effects

Edited August 19, 2019 by FreeThinker

[pmborg]

1 hour ago, FreeThinker said:

notice there are 2 versions, the smaller version will create a much  larger exhaust.

• I am uploading a video to show how the ship will animate the new exhaust effects.
• Delta-V upgraded from 145M to 153M, updating the new Bussard Engine, with full size InterStellarShip: 50/62 pax

 

Edited August 19, 2019 by pmborg

[pmborg]

• Payload 290tones 163M delta-V, crew 50/62.
• Payload 2tones 170M delta-V, crew 1.

Actually with this new engines I could redesign the InterStellar Ship to something that now make much more sense, but the engine nozzle seems that is scaling somehow odd:

Ship name: "Daedalus_and_Bussard-v4-163.5M":

 

[FreeThinker]

1 hour ago, pmborg said:

• Payload 290tones 163M delta-V, crew 50/62.
• Payload 2tones 170M delta-V, crew 1.

Actually with this new engines I could redesign the InterStellar Ship to something that now make much more sense, but the engine nozzle seems that is scaling somehow odd:

What about my suggestion of using multiple dropable radial balllon tanks, it would  allow you to save on engine mass as you could use multiple ballons tanks with a single engine.

The Idea is to empty and drop 2 tanks at the same time, allowing you to lose dead weight while not throwing away heavy engines

Edit: I notice the Radial Tanks currently are missing a configuration for storage of Solid Hydrogen, but I can fix that.

Edited August 19, 2019 by FreeThinker

[pmborg]

8 minutes ago, FreeThinker said:

What about my suggestion of using multiple dropable radial balllon tanks, it would  allow you to save on engine mass as you could use multiple ballons tanks with a single engine.

I tried already but somehow struggling to make it really working fine, but in theory would give even much more delta-V for sure, I need to come back to that idea.

BTW: about those radiators, please note that you will be always with a star at your back or with a star in front of you, that is a bad position for the radiators that should not be 90deg. with the star.

 

 

Edited August 19, 2019 by pmborg

[FreeThinker]

30 minutes ago, pmborg said:

BTW: about those radiators, please note that you will be always with a star at your back or with a star in front of you, that is a bad position for the radiators that should not be 90deg. with the star.

Well for 20 century low temperature radiators that would  be true but for hiigh temperature radiator that get as hot as in interstellar, the absorbed radiation from any star would be insignificant compaired to the radiation transmitted by a high temperature radiator. A much worse problem would be this would heat up your fuel tanks and engine, therefore it is recommended to used solid raditions which radiate outwards. Notice solid radiators are also lighter than deplyable radiators which becomes important when scaled up.

30 minutes ago, pmborg said:

I tried already but somehow struggling to make it really working fine, but in theory would give even much more delta-V for sure, I need to come back to that idea.

Understand that the more you scale up, the larger percentage of your ship will consist out of tank mass, so any way to reduce  the dead weight of empty fuel tanks becomes a big delta V win when scaled up.

Edited August 19, 2019 by FreeThinker

[pmborg]

3 minutes ago, FreeThinker said:

Well for 20 century radiators that would  be true but for radiator that get as hot as in interstellar radiators , the absorbed radiation from any star would be insignificant compaired to the radiation transmitted by a high temperature radiator.. A much worse problem would be this would heat up my tanks, therefore it is recommended to used solid raditions which radiate outwards. Notice solid radiators are light than deplyable radiators which becomes important when scaled up.

Disadvantage:

• Maybe its just me but, I don't like the idea of have a Radiator, irradiating heat towards engine and towards fuel tanks.
• The drag of the "empty" (not empty space) at speed about 56% speed of light or even half of that, but in this case, but once the speed is quadratic will be very high or they can break? can we risk that?

I use this to calculate the drag in atmosphere, for a launch using KOS to control the drag and the respective power:

• set Cd to .20075*.008.
• set p0 to 1.223125.
• set e to 2.71828.
•  
•     set H to altitude/(-10000).
•     set p to p0*(e^H).
•     set r to altitude+BODY("Kerbin"):radius. //600000.
•     set g to GM/(r^2).
•     set Qmax to g/Cd.
•  
•     set Vs2 to (Vsx^2)+(Vsy^2)+(Vsz^2).    
•     set q to .5*p*(vs2).

In Vacuum of space should be:

q = 1/2 * p * 170 792 458 * 170 792 458 (for my record delta-V)

Fd (drag force) = q * Cd * A

The question is what is the "p" in vacuum of space, between:

0.3×10^-27 kg to 1.67×10^−25

Cd=0.84 in that shape

 

Trying again that idea of radial tanks.

 

 

[pmborg]

About the radial tank the problem start with the delta-V calculation.

Ofc delta-v can always be calculated by "hand", can you use Kerbal Engineer Redux for that?

[pmborg]

ok, found the solution playing with priorities, that way Kerbal Engineer Redux  is able to do the math.

Edited August 19, 2019 by pmborg

[pmborg]

lol that break my record for now... but not with radial yet, only in serial: 191M delta-V, 6 stages (63.867% light speed)!

I think I found a way to make it work... trying it

 

[pmborg]

I found that a par of radial tanks in theory can be just one tank in serial tank. so I still cant find a way to make it a valid choice.

Applying this to 1 engine in a 10 tank stages, the ship can go now at 251M delta-V, 10 stages (83.867% speed of light )!

Edited August 19, 2019 by pmborg

[pmborg]

Trying now do the math to check which version of these two ships arrive faster to alfa centauri, the "slow acceleration" (faster terminal speed 251M/2) or that "fast acceleration" (slower terminal speed 170M/2)?

[pmborg]

Math for acceleration time/needed for 251M/2:

Edited August 19, 2019 by pmborg

[FreeThinker]

10 hours ago, pmborg said:

Ofc delta-v can always be calculated by "hand", can you use Kerbal Engineer Redux for that?

Do notice that the reactor also needs fuel (which is not taken into account by Kerbal engener), but this should be less then 1% of total. Justtake that into account

9 hours ago, pmborg said:

I found that a par of radial tanks in theory can be just one tank in serial tank. so I still cant find a way to make it a valid choice.

Applying this to 1 engine in a 10 tank stages, the ship can go now at 251M delta-V, 10 stages (83.867% speed of light )!

Do notice you stil need to acclerate up, which means maximizing deltaV might not the only variable to take into account.

Edited August 20, 2019 by FreeThinker

[pmborg]

"Do notice you stil need to acclerate up, which means maximizing deltaV might not the only variable to take into account. "

• Yes true, I am still doing the Math to reach to best point of equilibrium point, until now I was kinda limiting my self to a  min. TWR of 0.15 but tried to put away that limitation and check what is possible to get.
• I am still convict that is possible to reach the speed of light with these engines, I have the mental image of what is needed just need to model the idea.

"Do notice that the reactor also needs fuel (which is not taken into account by Kerbal engener), but this should be less then 1% of total. Justtake that into account"

• I will check this thanks!

[pmborg]

( Still not counting with Reactor fuel usage, yet )

For Ship 251M:

For Ship 170M:

 

The time to travel to Alfa Centauri is about the same, I prefer the cheaper and lighter ship then the 170M

Edited August 20, 2019 by pmborg

[pmborg]

Like I was imaging mixing 2xDeadlus (5 stages) and 1xBussard M251(10 stages) it's possible to reach 272M delta-V but the cost of the ship will increase dramatically.

For a payload 2tones + 1 crew:

Ship version 170M delta-v	392,241,086,486 cost
Ship version 251M delta-v	11,361,890,304 cost
Ship version 272M delta-v	2,936,308,498,432 cost

For a payload 289tones + 50/62 Crew:

Ship version 164M delta-v

5,288,795,136 cost

( This is the most realistic version so far, I think.  )

Speed of light: 54.867%        164,600 km/s
Speed of light: 56.667%        170,000 km/s
Speed of light: 83.867%        251,600 km/s
Speed of light: 90.867%       272,600 km/s

@FreeThinker, The reactor fuel usage, I am using the "Tri Aplha Colling Beam Fusion" no fuel usage observed at least.