KSP Interstellar Extended Continued Development Thread

[iontom]

8 hours ago, FreeThinker said:

Yes, you ran into the classic mistake in thinking a few kg of antimater could get you to another star. Although Antimatter is very powerfull for every gram, it storage density and effective mass (including container mass) is actually horrible. This isn't a big problem until you need to continuously power something for more than a day. Antimatter is not a power source, its a powerfull but very inefficient power storage method. This is the cruel joke that is common in interstellar, everything interesting is difficult or very temporary. A far more efficient method is to use Antimatter Initiated Fusion, which uses antimatter merely as the spark create real power from mass because that what fusion is, a limited means to convert mass to energy. The most effiicient means of producing energy from mass is to use a small black hole, which is feed by mass, which get evaporated to hawking radiation. This is what the Quantum singularity reactor was made for. For balance reasons I kept it a pure power reactor, but I have plans to alow it to generate charged particles which can be used for propulsion.

Hmm... What's the basis for the constraints on anti-matter storage? Penning Traps? Are Anti-Matter Catalyzed Fusion is supposed to have much steeper limits on max Delta-V because of the Tsiolkovsky problem. (AIM and  ACMF shown here):

Magnetic Nozzle Exhaust Velocity

Also - I needed to hook up my Antimatter reactor to a Particle Generator - in order to get the magnetic nozzle to work - but shouldn't the reactor be generating charged particles already?
From your description page:

Quote

Antimatter reactors versatile , expensive, and incredible powerful, the only real problem is collecting significant amount of Antimatter. They produce up to 80% Charged Particles which can be used by magnetic nozzle to create a large amount thrust an high Isp

Magnetic Nozzles hooked up to a Beam Core reactor could potentially be expelled at close to 0.69 C 

http://newatlas.com/beamed-core-antimatter-propulsion/22654/

ANTIMATTER STORAGE

There's groups like Positron Dynamics which are trying to commercialize a trend in positron confinement which actually uses special electron modes in simple neutral molecules. 
http://web.am.qub.ac.uk/users/g.gribakin/papers/p4541_1.pdf
http://www.sciencedirect.com/science/article/pii/S0009261417302464

So there could potentially be more compact storage mechanisms for anti-matter as a more sophisticated tech. I think right now you're at around 1 kg / tank ?

MICRO-LINEAR ACCELERATORS

There's also currently development on small linear accelerators powered by lasers which could be used to transform any waste heat from either AntiMatter or a Fusion reactor into relativistic laser-accelerator nozzles. ( I'm still trying to find things like energy requirements for the lasers, but I think it's really low.) The ISP is going to be incredibly high, the thrust microscopic - but that might go up depending on whether this same miniaturization can work on higher mass ionized nuclei. You might even be able to push particles all the way up to iron if you wanted to. But really you'd probably end up using something like this to blast Oxygen that you will have a LOT of if you store your hydrogen or deuterium in water.

https://www6.slac.stanford.edu/news/2013-09-27-accelerator-on-a-chip.aspx

http://www.nature.com/nature/journal/v503/n7474/full/nature12664.html

MAGNETIC SAILS

Anyway - WAY more economic is Magnetic Sails for Breaking and Refueling - you basically get close to free  deceleration - you just need enough energy to keep a small current in your super conducting loops. And you can actually hold onto the interstellar particles you capture - potentially for use later in your micro-accelerator nozzle. MagSail will work more efficient the faster you are moving, but becomes negligible under 2000 km/s

https://www.semanticscholar.org/paper/Combining-Magnetic-and-Electric-Sails-for-Perakisa-Heinb/8278b9c81dd18c0a5dbea3b8e68b6ef25617c4d2

You also get extra deceleration from an E-sail too - which is a slightly different configuration and can break on a stellar wind as a spacecraft enters a system.

How it might play out in Kerbal is just that if you have the magsail activated, it would slow your velocity until you hit the breaking limit. The E-Sail might work like the already existing solar sail - which also might do well as a conversion to a solar sail. Multi-stage spacecraft are a must for efficiency. 

Thanks for listening!

 

[FreeThinker]

20 hours ago, iontom said:

Magnetic Nozzle Exhaust Velocity

Also - I needed to hook up my Antimatter reactor to a Particle Generator - in order to get the magnetic nozzle to work - but shouldn't the reactor be generating charged particles already?
From your description page:

Magnetic Nozzles hooked up to a Beam Core reactor could potentially be expelled at close to 0.69 C 

http://newatlas.com/beamed-core-antimatter-propulsion/22654/

 

 

 

 

 

 

 

 

Interesting, but how to calculate effective maximum Isp?

KSPI currently does the following calculation to derive max isp

double joules_per_amu = _attached_reactor.CurrentMeVPerChargedProduct * 1e6 * ELECTRON_CHARGE / 15000.0;
calculatedIsp = Math.Sqrt(joules_per_amu * 2.0 / ATOMIC_MASS_UNIT) / STANDARD_GRAVITY

where 

ELECTRON_CHARGE = 1.602176565e-19
ATOMIC_MASS_UNIT = 1.660538921e-27
STANDARD_GRAVITY = 9.80665f

This is my problem, it's all cool to talk about advanced sci fi concept, but when it comes to applying all that power to the tarmac, you need to do some hard math, this is where most popular science halts and you are thrown into the deep end.

lets do some raw math.

Considering D-He3 has an average exhaust velocity of 8.9%c, then antimatter is 7.75 times the isp of D-He3 fusion. 7.75 1.500.000s = 11.625.000 s

Or directly 0.67c * 300.000.000 m/s * 55% efficiency / 9.81  =  11.269.113 s

Edit: at least in this case there is a source document we can use

Edit2: Found an interesting document on how to calculate isp from product MeV

Edited March 30, 2017 by FreeThinker

[SpaceX]

That would be awesome! 

 

Looking the details over, it seems like it would be a perfect fit. Perhaps needing a little love along the way.. but a great addition all the same.

19 hours ago, FreeThinker said:

Well I was hoping to integrate with

 

This would be incredible! 

[iontom]

8 hours ago, FreeThinker said:

This is my problem, it's all cool to talk about advanced sci fi concept, but when it comes to applying all that power to the tarmac, you need to do some hard math, this is where most popular science halts and you are thrown into the deep end.

 

Totally agree, and you know exactly where to start with this Q

Quote

Interesting, but how to calculate effective maximum Isp?

That is the question - and I think you were able to answer the component that I wasn't sure on, which was how KSP calculates it. Which is that is uses STANDARD_GRAVITY = 9.80665f for g0

Where V_ex is the exit velocity. If the Isp calcs always just assume g0 to be zero, then it's not really a true ISP, but it's the I don't know the term... "Effective Isp" for Earth/Kerbin. In which case yes, your calc holds.
0.67c * 300.000.000 m/s * 55% efficiency / 9.81  =  11.269.113 s (periods instead of commas, you must be European!)

Of course, that's not the Actual Isp, which to use that, you'd either use the gravitational force of the Sun, or of the galaxy itself in place of g_0 . Which, for interstellar flight is essentially worthless. You can solve for g_galaxy and get (6.67408e-11)*(5.8e11*1.989e30)/(5e20)^2 = 3.0797409e-10 but that's treating the galaxy like one big Keplerian system, which is totally false. It's just flat wrong, you need to derive Isp in some other way.

http://www.relativitycalculator.com/rocket_equations.shtml

Or more simply So, I guess you'd need to define "weight" without using g0 - and the only way I think you can do that would be to derive it from a change in relativistic kinetic energy....Which would be variable depending on whatever your current velocity was. And I'm NOT about to try to piece that out.

Anyway - you don't need to worry about any of that, because for how KSP handles the physics your 11269113 s Isp sounds right on the mark.

Isp is just a notation - so g0 doesn't really matter, still the value you came up with11 times higher than what the magnetic nozzle currently tops out at - which I think is closer to what makes sense from the NIAC dV charts I keep showing.

Now since, I've got your attention, might I inquire your thoughts about laser-driven sails that might function like your Beamed Power network?

Laser Sail Eqs.

http://muonray.blogspot.com/2016/06/the-spacecraft-that-requires-no-fuel.html
http://www.jsforum.or.jp/ISSS2017/papers/paper/17021_Paper_Bernd Dachwald.pdf

Technically - photon sails work with solar incident rays and lasers - so you have two additive forces. This would probably be harder to model in Kerbal since it requires vector dot products and 

There's a lot of variables in there - but mostly it's just a function of:

• Sail area (A)
• Beam distance (because of dispersion)
• Incident angle
• Photon Energy - which wavelength

The beam direction you might assume is just a straight line linking the beam source to the sailcraft - and leave it up to the player to figure out which direction to point so that they can either tack into or away from the incoming light. Still - I could see where that gets really tricky to model into KSP. Especially if you wanted to turn on multiple beams at once as part of a grid (you absolutely would).

Magnetic Sail Eqs.

Magnetic sails are a lot easier, at least if you only care about deceleration. Basically if you're going above 2000 km/s, turn on your magsail and you'll just simply lose velocity with a force strength dependent on your current velocity. 

http://www.academia.edu/28394236/Combining_Magnetic_and_Electric_Sails_for_Interstellar_Deceleration

 

* Don't miss the radical up there ^(3/2) - also, m_p is usually just molecular hydrogen.

I guess - you'd want to have the sail "deploy" once you're in space, because it's going to be huge and thin. And the radius you choose in the hangar would determine your speed. Also, depending on how you set it up - you would acquire interstellar hydrogen too - as you moved. 

What I'd like to find is an equation that would tell you how much hydrogen you gain as a function of velocity. It would also be slightly random, but within a set of parameters. You could mag-break down to 2000 km/s over about 10 years, and then have a nearly full tank of hydrogen from which you could do final deceleration/course correction.

Hope some of that helps!

Edited March 30, 2017 by iontom
being dumb

[Red Iron Crown]

1 hour ago, iontom said:

That is the question - and I think you were able to answer the component that I wasn't sure on, which was how KSP calculates it. Which is that is uses STANDARD_GRAVITY = 9.80665f for g0

Where V_ex is the exit velocity. If the Isp calcs always just assume g0 to be zero, then it's not really a true ISP, but it's the I don't know the term... "Effective Isp" for Earth/Kerbin. In which case yes, your calc holds.
0.67c * 300.000.000 m/s * 55% efficiency / 9.81  =  11.269.113 s (periods instead of commas, you must be European!)

Of course, that's not the Actual Isp, which to use that, you'd either use the gravitational force of the Sun, or of the galaxy itself in place of g_0 . Which, for interstellar flight is essentially worthless. You can solve for g_galaxy and get (6.67408e-11)*(5.8e11*1.989e30)/(5e20)^2 = 3.0797409e-10 but that's treating the galaxy like one big Keplerian system, which is totally false. It's just flat wrong, you need to derive Isp in some other way.

 

Specific impulse is not dependent on gravity, g₀ is used as a convenient, usually memorized constant to put it in units that are equally friendly to metric and imperial unit systems (i.e. seconds). It is never different from 9.80665m/s² no matter what the local gravity conditions.

[FreeThinker]

3 hours ago, iontom said:

Now since, I've got your attention, might I inquire your thoughts about laser-driven sails that might function like your Beamed Power network?

Laser Sail Eqs.

http://muonray.blogspot.com/2016/06/the-spacecraft-that-requires-no-fuel.html
http://www.jsforum.or.jp/ISSS2017/papers/paper/17021_Paper_Bernd Dachwald.pdf

Technically - photon sails work with solar incident rays and lasers - so you have two additive forces. This would probably be harder to model in Kerbal since it requires vector dot products and 

There's a lot of variables in there - but mostly it's just a function of:

• Sail area (A)
• Beam distance (because of dispersion)
• Incident angle
• Photon Energy - which wavelength

The beam direction you might assume is just a straight line linking the beam source to the sailcraft - and leave it up to the player to figure out which direction to point so that they can either tack into or away from the incoming light. Still - I could see where that gets really tricky to model into KSP. Especially if you wanted to turn on multiple beams at once as part of a grid (you absolutely would).

Yes, that has been a goal for me for quite some time to create photon sail vessels. I have been focusing first on the infrastructure, which are the beam generators, beam transmitter and mirrors/receivers to collect and redistribute the power where we want it. I even found an effective method of using the sun as the main power source.

But to create beamed powered photon sail I need 2 main ingredients,

A  model that can unfold to a solar sail with decent proportions and

B a formula that generates effective thrust given total received power, incidence angle (cos x), wavelength (if that matters)

now for problem A I need a modeler with enough imagination and skill to create a solar sail, which is quite difficult because, no one has ever done it! For problem B I a need a mathematician/scientist. Problem A might temporarily overcome by using the existing photon sail, which is basically a projection of a large  gold square, for problem B I'm hoping you can help me.

Edited March 30, 2017 by FreeThinker

[iontom]

40 minutes ago, FreeThinker said:

Yes, that has been a goal for me for quite some time to create photon sail vessels. I have been focusing first on the infrastructure, which are the beam generators, beam transmitter and mirrors/receivers to collect and redistribute the power where we want it. I even found an effective method of using the sun as the main power source.

But to create beamed powered photon sail I need 2 main ingredients,

A  model that can unfold to a solar sail with decent proportions and

B a formula that generates effective thrust given total received power, incidence angle (cos x), wavelength (if that matters)

now for problem A I need a modeler with enough imagination and skill to create a solar sail, which is quite a difficult because, no one has ever done it! For problem B I a need a mathematician/scientist. Problem A might temporarily overcome by using the existing photon sail, which is basically a projection of a large  gold square, for problem B I'm hoping you can help me.

I think if we ask really nicely, I can get my friend Seth to make the model, although animating it might be way too complicated. 

In terms of the incidence angle - I'll try to get some more information in regards to laser driven sails - but for solar sails at least it's a pretty straightforward  

F=F_0*(cos2θ/R2)

http://space.stackexchange.com/questions/2997/can-i-derive-a-combined-equation-for-velocity-of-solar-sail

I'll do some more derivation later today though. What it will need however is some mechanism for calculating the beam direction from a laser station to the sailcraft. And you'd ideally want to use more than one beam station at a time. And even possibly a beam array from the surface of a body like the Mun. You could do it from the surface of Kerbin too - but you would have wavelength restrictions. We would also be assuming here that all of the lasing stations are capable of perfect beam orientation. 

So you would need to be able to get the directional vector, distance and atmospheric properties of a world to know the force your sail would receive, then your sailcraft force calculator would have to add all of those together and do simple force addition. Each beam station would have it's own incidence angle, but as you got further away from the Kerbol system, the difference in angle from each station would shrink, and all of the forces would be aligned.

You also have the issue of placing a large collimating lens, which could be used to extend the usefulness of the beam. If you parked one of those in a "slow" hyperbolic orbit headed towards your destination - you could then have subsequent beamcraft ride the beam much further.

From a programming perspective, I think you'd have to be able to "Set Target" for beaming stations while they are in Momentum Beaming Mode.
THEN IF target = lightsail DO Add Sum(i=0, N){BeamingForce[Theta, R]} Return SailForceVector
ELSE IF target = collimator DO Add CREATENEWBEAM[Sum(i=0, N){BeamingForce[Theta,R]}] Return StrongBeam

So basically the Collimator would function just like a Beam Station, except that it would combine the forces of multiple other stations and it would have a much more effective force distance. I will start looking up what those force values will be - but essentially that's the architecture involved.

Magbreaks would probably be programmatically easier to tackle since they would only be a function of a spacecraft's velocity.

Cheers!

[FreeThinker]

Version 1.12.17 for Kerbal Space Program 1.2.2

Released on 2017-03-31

• Fixed Daedalus Fusion Engine ability to function in real time and time warp

[SpaceX]

Dude - You are a legend sir!

4 hours ago, FreeThinker said:

Version 1.12.17 for Kerbal Space Program 1.2.2

Released on 2017-03-31

• Fixed Daedalus Fusion Engine ability to function in real time and time warp

Seriously - thank you so very much for providing me endless hours of learning and entertainment in KSP...this mod continues to teach me things daily! I love it.

 

Thanks!

[FreeThinker]

8 hours ago, iontom said:

I'll do some more derivation later today though. What it will need however is some mechanism for calculating the beam direction from a laser station to the sailcraft.

Vector3d sunPosition = FlightGlobals.fetch.bodies[0].position;
Vector3d ownPosition = this.part.transform.position;
Vector3d ownsunPosition = ownPosition - sunPosition;
Vector3d normal = this.part.transform.up;

// If normal points away from sun, negate so our force is always away from the sun
// so that turning the backside towards the sun thrusts correctly
if (Vector3d.Dot(normal, ownsunPosition) < 0)
	normal = -normal;
  
// calculate cosine angle                                             
double cosConeAngle = Vector3.Dot(ownsunPosition.normalized, normal);                                             
                                             
// Magnitude of force proportional to cosine-squared of angle between sun-line and normal
Vector3d force = normal * cosConeAngle * cosConeAngle * surfaceArea * reflectedPhotonRatio * solarForceAtDistance();
                                             
                                             

I think if we replace the sun position by our beam power station position and can calculate effective photon force received (from beamed power sat) we have calculated effective photon sail force

Now what I need is the photon beam to thrust conversion.

A possible number I derived from the solar sail engine is 6.5 Newton  / photon GigaWatt , but I'm not sure if this is correct

But what I do know is that a photon engine produces  3.3333 N / GigaWatt, and I heard for solar sail this is doubled because of double impulse transfer., which would mean 6.6666 N / GW seem very close to the number above

Note that I'm not sure if the wavelength has any effect except on beam divergence. According to one of my friends calculations it doesn't because shorter wavelength photons become fewer but more powerful, canceling each other out.

 

Edited March 31, 2017 by FreeThinker

[raxo2222]

It seems like there are some issues with dry/wet mass ratio scaling, when FAR is installed.

It seems like you can actually find these bugs with Kerbal Engineer.

 

Edited March 31, 2017 by raxo2222

[iontom]

13 hours ago, FreeThinker said:

 

But what I do know is that a photon engine produces  3.3333 N / GigaWatt, and I heard for solar sail this is doubled because of double impulse transfer., which would mean 6.6666 N / GW seem very close to the number above

Note that I'm not sure if the wavelength has any effect except on beam divergence. According to one of my friends calculations it doesn't because shorter wavelength photons become fewer but more powerful, canceling each other out.

 

Yep! 2x the momentum! Here's a good article on it - http://muonray.blogspot.com/2016/06/the-spacecraft-that-requires-no-fuel.html

The force itself is bundled up inside of "E" and is based on both the energy/freq of the photon and the work function of the metal that does the reflection - but for the most part that is assumed to be pretty high. ( between 0.88 to 0.9 reflective ) And technically this efficiency may change as you move since the photons reaching the sail will be more redshifted as the spacecraft moves faster - but that won't change by enough that it's worth modelling.

Here's a good walkthrough!
http://ffden-2.phys.uaf.edu/webproj/212_spring_2015/Robert_Miller/physics.html

Perfect Sail: (theta is the angle between your light source and the normal vector of the sail)

Realistic Sail:

Now you just need to find F_0

For now we might assume that the reflectivity ( k ) is at a happy 0.9

The Beam Intensity (capital I) is not shown here - since this is a Solar Sail rather than a Laser Sail - (but don't forget to include the sun in the laser sail model - it will have a small but negligible force - and you could possibly break against other stars to decelerate)

So, intensity for a star is measured in Watts/m^2 - and you probably have the Eqs for that in the existing solar sail mod you have.

For lasers - the peak intensity is based on wavelength and something called the Optical Power - which is the factor where dispersion will come in.

    (w is the freq. P here is a the Optical Power, and is function of many different things including source distance)

https://www.quora.com/Is-the-light-from-lasers-reduced-by-the-inverse-square-law-as-distance-grows-similar-to-other-light-sources

(***NOTE***  Theta here is not the same as the Theta before. This Theta is the dispersion angle. )

What we need to find is the Optical Power and the Dispersion Angle

Which - we may need to ask around for that - and/or scour the literature from the UCSB DEEP-IN Group that's working on laser sails because they do simulations on this stuff already.

http://www.deepspace.ucsb.edu/projects/directed-energy-interstellar-precursors

We also should assume that each lasing station will in-itself be functioning as a complete phased array - which make finding clean numbers a tad harrier - but they will be the same for each lasing station used. 

Once we find P and the Dispersion Angle, we'll have a good approximation of the force. The last step will just be adding the forces. And maybe we'll treat the collimator as it's own object. Which we can do the physics on later - but it will have the same dispersion and optical power traits as just the basic laser.

F(total) = F(nearest star irradiance) + SUM(F_lasers(IS_TARGET, Laser_Position_3Vec, Laser_Wavelength, Laser_Optical_Power, Laser_Dispersion_Value=)) + SUM(F_collimator(SUM(Input_Lasers), NewDispersion, NewOpticalPower)

 

[iontom]

Alright - adding some more -this paper is great

http://www.deepspace.ucsb.edu/wp-content/uploads/2013/09/zhang_spie2015_SAIL-r815a.pdf

It gives sail size based on max payload. So conversely - if you allow for multiple sizes of the sail - you could provide an estimated max payload. (of course you can discard your sail after it's used up too.)

Which, we can solve for m_sail instead based on pre-set sail diameters. Also - how big can we make models in KSP? Is a 10km diameter sail possible once deployed? There's tons of other cool stuff on here.

Anyway - I thought you might like this:

http://www.deepspace.ucsb.edu/wp-content/uploads/2015/04/Laser-Propulsion-Classical-1D-Standalone.html

If you view the page source, all the calculations are in there in the javascript, preformatted for you. Of course - the calculator doesn't seem to include anything about the beam dispersion - this is specifically for a phased array mission like the Breakthrough Starshot - and does NOT include the option for using a Collimating Lens - which would let you keep the laser active for probably more than 1000x longer.
 

http://www.geoffreylandis.com/lightsail/Lightsail89.html

 

Edited March 31, 2017 by iontom

[Nansuchao]

26 minutes ago, iontom said:

Alright - adding some more -this paper is great

http://www.deepspace.ucsb.edu/wp-content/uploads/2013/09/zhang_spie2015_SAIL-r815a.pdf

It gives sail size based on max payload. So conversely - if you allow for multiple sizes of the sail - you could provide an estimated max payload. (of course you can discard your sail after it's used up too.)

Which, we can solve for m_sail instead based on pre-set sail diameters. Also - how big can we make models in KSP? Is a 10km diameter sail possible once deployed? There's tons of other cool stuff on here.

Anyway - I thought you might like this:

http://www.deepspace.ucsb.edu/wp-content/uploads/2015/04/Laser-Propulsion-Classical-1D-Standalone.html

If you view the page source, all the calculations are in there in the javascript, preformatted for you. Of course - the calculator doesn't seem to include anything about the beam dispersion - this is specifically for a phased array mission like the Breakthrough Starshot - and does NOT include the option for using a Collimating Lens - which would let you keep the laser active for probably more than 1000x longer.

EDIT: Also adding this paper by Landis
http://www.niac.usra.edu/files/studies/final_report/4Landis.pdf

In KSP you can't build anything bigger that 2.5 km, cause the physic bubble has that size. However, Unity is terrible at handling huge object, so it will very likely go crazy with something so massive. 

I guess 100-200 squared meters it's the max size you can try almost safely.

[SpaceX]

Does anyone have any ideas as to what I can use solar wind for? I see that I can harvest solar wind, but am seemingly unable to find out what I'd be able to use this resource for...

 

thanks in advance!

 

Edit - I was informed that it's a special feature on one of the ISRU parts - So a harvesting we'll go.

Edited April 1, 2017 by SpaceX

[FreeThinker]

11 hours ago, iontom said:

So, intensity for a star is measured in Watts/m^2 - and you probably have the Eqs for that in the existing solar sail mod you have.

Yes but I intend to replace it by stock property

part.vessel.solarFlux

Which will automatically determine if it is blocked by a celestial body and will scale with any solar system/galaxy mod, making it function correctly near red dwarfs of  super giants

Edited April 1, 2017 by FreeThinker

[FreeThinker]

13 hours ago, iontom said:

We also should assume that each lasing station will in-itself be functioning as a complete phased array - which make finding clean numbers a tad harrier - but they will be the same for each lasing station used.

This is what I technically effectively already do. Any station with at least 2 dishes, a receiver (configured to link to network) and a transmitter set to relay will behave as a phased array.

13 hours ago, iontom said:

F(total) = F(nearest star irradiance) + SUM(F_lasers(IS_TARGET, Laser_Position_3Vec, Laser_Wavelength, Laser_Optical_Power, Laser_Dispersion_Value=)) + SUM(F_collimator(SUM(Input_Lasers), NewDispersion, NewOpticalPower)

This is technically already done by beamed power receiver, except of using the power for direct momentum exchange, it is used for power production. This is the reason I want them to work together.

Related to this

Quote

A fundamental problem with laser-propelled lightsails is the extremely low energy efficiency of 6.7 nt/GW. The energy efficiency may be greatly improved, at the cost of a reduction in specific impulse, by combining the laser sail with a photovoltaic powered electric (ion) engine. Ion engines in principle have no physical limits on the specific impulse, although extremely high specific inpulses require proportionately high energy consumption. Such a laser-powered rocket would have the ability to decelerate at the target star (with some loss of efficiency), and could also greatly decrease the amount of power required from the laser. Fig. 4 shows a schematic for such a rocket, where the solar array is mounted at a position where the sail acts as a mirror to focus light on it. (The drawing shown implies that the sail is light enough that it will propel itself ahead of the engine and payload; if this is not the case, the ion engine would have to be configured to pull the sail, with, for example, many smaller ion engines firing through individual small openings in the sail.) An alternate version would be to form thin-film solar cells [20] directly on the sail. The specific impulse of such a system can be extremely high as long as the mass flow rate of reaction mass is low; but even with extremely low mass flow rates the energy efficiency of the sail can be greatly improved.

Which gives me an idea, we could assume the solar sail has 2 sides, one is used exclusively for reflecting photons, the other side would have a thin film solar cells integrated, allowing it to act as a huge solar array, allowing it to propel an electric engine at a high isp. It would be ideal for orbital maneuvers, which especial near celestial bodies becomes important.

Quote

Another alternative is to use a beam with a wavelength shorter than light. One such solution is to use a particle beam. Diffraction is not a problem. The particles would have to be charged to be accelerated and focused, and then neutralized to avoid beam expansion due to electrostatic repulsion*. The particles could then be re-ionized and reflected by a magnetic sail [8].

A difficulty is beam spread due to random thermal velocity. Thermal beam spread decreases proportionately to the square root of the atomic mass. Using mercury (atomic mass 80) as an example, the lateral velocity due to thermal motion is 1.4 T ^1/2 m/sec, where T is the temperature in degrees Kelvin. Existing ion accelerators have typical beam temperatures of hundreds to thousands of degrees, but this can in principal be reduced by any of several known techniques. The limit to the minimum temperature that can be theoretically achieved for the beam is the cosmic background temperature of about 3 K; which would lead to a beam spread of 300,000 km at a distance of 4 LY.

This could be reduced if the beam particles condense to larger particles after acceleration. To reduce the beam spread by a factor of 1000, the number of mercury atoms per condensed droplet needs to be at least a million. This is an extremely small droplet (10^-16 grams) by macroscopic terms, and it is not unreasonable to believe that such condensation might take place in the beam. As the droplet size increases, this propulsion concept approaches that of momentum transfer by use of pellet streams, considered for interstellar propulsion by Singer [22].

This might be the ultimate beam power solution possible, I currently have an artist creating a particle beam model, which would allow very efficient high power propulsion.

The best location for this would be on the surface of a celestial body without an atmosphere. The moon would be perfect for this. It could use the waste regolith of the moon itself (after you removed all rare element first)

Besides propelling spacecraft, they would also be effective in diverting commits that threaten earth. It would simply continuously bombard the comet until is trajectory is averted. I'm earth inhabitant will be thankfull for this.

Edited April 1, 2017 by FreeThinker

[Thorbane]

Would it be possible to calculate and display the maximum sustainable power output of your reactors and the thrust you can produce with that power?  This would allow for estimated burn times that are actually accurate.

[juanml82]

Hi, I'm using the JX2 Antenna mod (here)

together with KSPI-E. I guess the issue is due something in the MM patch that turns antennas into relays for the power network: when used in conjunction with KSPI-E, the antenna get a huge thermal power "tank" which keeps demanding thermal power. So if I make a ship powered, for instance, with the gas core nuclear engine, even with the engine idle, the antenna keeps demanding thermal power to the engine's reactor and no matter how many radiators I add, the reactor ends up shutting down due overheating. Here's an example craft

http://www.mediafire.com/file/qckpj97cc54gnr7/Surveyor_3.craft

[FreeThinker]

@juanml82 please ask any mod questions or problems in the release thread I'm trying to keep this tread purely be development discussions

Edited April 2, 2017 by FreeThinker

[FreeThinker]

Version 1.12.18 for Kerbal Space Program 1.2.2

Released on 2017-04-04

• Added Megajoule to Electric Charge converter, Command Modules, SAS and KerbNetAccess to Shielded Diode Laser Beam Transmitter, allowing it to function as a probe core
• Added automated Megajoule and 300 MJW capacity to Computer core and allow it to accept electric charge to run the core
• Added Tweakscaling to Truss parts
• Balance: MCF reactor can now be scaled smaller with increasing fusion tech
• Balance Reduced power Nuclear lightbulb by 12.5%
• Balance Increased sensitivity embrittlement for Nuclear Lightbulb
• ISRU processes synthesize processes no require and produce gasses instead of cryogenic liquids
• Fixed an exception at startup in thermal receiver slaves, causing it to not be correctly initialized resulting in overheating in NF mode
• Fixed incorrect embrittlement effect
• Fixed tweakcaling effective collector ability Antimatter collector
• Fixed tweakcaling effective receiver beamed power capacity

[Jumberlack]

So I've been trying to get a warp craft to work but when I get going the quantum singularity reactor decides to shut off and knocks me out of warp. The reactor should be able to power warp at the speeds I was trying to go AND self sustain, yet it fails to do so. Can I change something to fix this? if not, can you make it so you can set fusion reactors that need power to sustain fusion to safeguard a portion of it's power towards keeping the reactor going, and instead of the reactor dying, the load would shut off? I'm not sure why this is broken because in theory the handoff should work but something about warp drives makes it not work or something.

[Profit-]

5 minutes ago, Jumberlack said:

So I've been trying to get a warp craft to work but when I get going the quantum singularity reactor decides to shut off and knocks me out of warp. The reactor should be able to power warp at the speeds I was trying to go AND self sustain, yet it fails to do so. Can I change something to fix this? if not, can you make it so you can set fusion reactors that need power to sustain fusion to safeguard a portion of it's power towards keeping the reactor going, and instead of the reactor dying, the load would shut off? I'm not sure why this is broken because in theory the handoff should work but something about warp drives makes it not work or something.

I was having some problems with this as well, however it has been happening less for me about 3 updates ago... Now most of the time it is temperature spikes. 

Edited April 5, 2017 by Profit-

[FreeThinker]

4 hours ago, Profit- said:

I was having some problems with this as well, however it has been happening less for me about 3 updates ago... Now most of the time it is temperature spikes. 

the SQR has an emergency shutdown fraction of 0.9, meaning that at 90% waste heat buildup it shuts down. This allows it to shutdown safely because otherwise the heat spike would cause the whole system to crash catastrophically.

The funny thing about black holes is the smaller they are, the higher their temperature becomes. An evaporating black hole will generate huge amount of hawking radiation which tops just before it disappears. That's why shutting down an SQR reactor is such a tricky endeavor and you need some safety buffer room.

I have been thinking on how make them more realistic. One Idea is to mate maintenance cost variable based on experience G-force. The reasoning is that the main maintenance cost is keeping the charged black hole located where it is, and prevent it from swallowing the vessel. This should make high acceleration, or placing it in a permanent gravity field, (like on the surface of kerbin) a very bad idea.

The upside is that, the black hole will create 2 charged particle streams, which at least one side can be used for magnetic nozzle propulsion. This would allow you to use it effectively use as a Kugelblitz engine, allowing reacing high percentage of the speed of light.

Besides variable maintenance cost, I want to make the startup of a QSR cost a significant amount of mass to create a miniature black hole in the first place, currently it only cost a lot of power which can be charged over time. theoretically anything could be used for this but technically you want the material to be as dense as possible. One of the densest material available in large quantities is depleted uranium

Edited April 5, 2017 by FreeThinker

[Nansuchao]

43 minutes ago, FreeThinker said:

the SQR has an emergency shutdown fraction of 0.9, meaning that at 90% waste heat buildup it shuts down. This allows it to shutdown safely because otherwise the heat spike would cause the whole system to crash catastrophically.

The funny thing about black holes is the smaller they are, the higher their temperature becomes. An evaporating black hole will generate huge amount of hawking radiation which tops just before it disappears. That's why shutting down an SQR reactor is such a tricky endeavor and you need some safety buffer room.

I have been thinking on how make them more realistic. One Idea is to mate maintenance cost variable based on experience G-force. The reasoning is that the main maintenance cost is keeping the charged black hole located where it is, and prevent it from swallowing the vessel. This should make high acceleration, or placing it in a permanent gravity field, (like on the surface of kerbin) a very bad idea.

The upside is that, the black hole will create 2 charged particle streams, which at least one side can be used for magnetic nozzle propulsion. This would allow you to use it effectively use as a Kugelblitz engine, allowing reacing high percentage of the speed of light.

Besides variable maintenance cost, I want to make the startup of a QSR cost a significant amount of mass to create a miniature black hole in the first place, currently it only cost a lot of power which can be charged over time. theoretically anything could be used for this but technically you want the material to be as dense as possible. One of the densest material available in large quantities is depleted uranium

If I can make a little suggestion, I would not allow the QSR to be activated on the surface a atmospheric world. The idea to use a dense material seems very good, but at that point, you can in theory create some Osmium, the densest known material.

 

About the G-Force, it should give less energy during acceleration, but not too much less, otherwise you risk to loose control of the BH and completely destroy the ship (at least).