Focused Solar Power Propulsion

tahanson43206 · 2024-12-14 11:51:07

This topic is inspired by recent work by kbd512.

It is created as a separate topic because it seems to be subtly different from the 30 other topics with the word "propulsion" in the title.

We will lead off in post #3 with an image created by GW Johnson showing one possible example of what such a craft might look like.

Substantial mathematics exploring this concept are available for study in topic "kbd512 Postings".

This topic is available for NewMars members who might wish to move beyond hand waving and onto Real Universe achievement.

This forum has 20+ years of hand waving in the archive, and some of it is ** really ** impressive!

GW Johnson is hard at work designing a Space Tug infrastructure for the Earth-Moon system, and the Solar Powered Propulsion idea recently brought back into focus by kbd512 has the potential to provide a way to push deep space vessels from the Moon out further in the Solar system.

Update: This topic is not about using solar power to generate electricity using solar panels or solar collectors to heat fluid to generate electricity.

The intention for this topic is to attempt to collect information about use of solar power to heat propellant, and to encourage design and construction of space vessels which will use this technology.

(th)

tahanson43206 · 2024-12-14 11:51:34

This post is reserved for an index to posts that may be contributed by NewMars members over time.

Post #3: GW Johnson: Model of spherical Focused Solar Power vessel
Post #5:
Post #6:
Post #7:
Post #8:
Post #9: kbd512: Latticed asymmetric resistojet thruster engine core design: << compare turbulent flow for heating to laminar

(th)

tahanson43206 · 2024-12-14 11:53:08

GW Johnson created an image that shows one of many possible ways to design a space vessel that would generate propulsion by collecting solar radiation for heating purposes.

Here is some text that arrived via email:

The definition says that 1 N = 1 kg * 1 m/s^2. Here on Earth, the standard acceleration of gravity is not 1 m/s^2 but instead pretty near 9.80667 m/s^2 (it actually varies a little with primarily latitude, and altitude. That says at sea level on a standard day near 45 degree latitude north, the weight of 1 kg is 9.80667 N. Divide through by 9.80667 and you find that 1 N = weight you feel of 1/9.80667 kg = 0.10197 kg = 101.97 grams. Which says your 102 gram's Earth weight really is 1 N. You got it right.
As for the thrust producible, the physics of that are just a lot more complicated. The thrust coefficient CF is set solely by the nozzle area expansion ratio for a vacuum rocket device. That's standard compressible flow analysis applied to expansion nozzles, which most people think is not simple. The thrust is F = CF Pc At, set by the definition of thrust coefficient, where Pc is the chamber pressure within the solar receiver, and At is the throat area. At low Pc, At must be large, for a given thrust, which means all the other chamber and nozzle dimensions must also be large, in turn meaning your equipment core must be very big and very heavy. You must use a high Pc to get a small At for a given thrust, to get your engine T/W down. Sunlight is a diffuse energy source, and can be concentrated only so far, because spherical mirrors do not focus. That means the receiver has to be physically large anyway. You are not free to choose those two effects independently.
As to the rest of the solar rocket idea, the problem faced will be the inherent slowness of the heat transfer processes. Heating 1 kg of anything through a temperature rise of 2700 K in only 1 sec is not going to be possible at the energy/area of even concentrated sunlight. It will just take longer than that, thus limiting the massflow for the size of mirror you can build. That third effect is also not independently set from the other two. See sketch attached.
GW

I note that this is one of ** many ** possible designs. It has the feature/drawback that the flight must be scheduled so that the Sun is at 90 degrees to the desired dV addition to the trajectory. For a boost from the Moon to Mars (for example) there should be plenty of opportunities when the needed conditions apply.

(th)

GW Johnson · 2024-12-14 15:19:49

If you can steer the spherical balloon collector relative to the core axis, the 90 degree thing is no longer a requirement. There are still angles that won't work, but there will be a majority that will work. But you get what you pay for: you must hold onto the balloon, and steer it to face where you need, and STILL get the rocket nozzle through the side of the balloon. That is NOT AT ALL easy! It will be heavy. Inherently!

GW

tahanson43206 · 2024-12-14 16:25:30

For GW Johnson!
Thanks for adding Post #3 (via email) and adding clarification with post #4.

From my perspective (not knowing the orbital mechanics) I would think that planning a flight path that keeps the Sun square abeam should be feasible. We may need to master GMAT to be sure. Or we can enlist someone like James Miller who has experience plotting courses for deep space missions.

***
For kbd512 re tomorrow's meeting ...

I'd like to (at least try to) encourage you to think about a solar trough a kilometer long,built using the ideas from GW's model, but extended in the longitudinal axis for as far as makes sense.

The basic model GW has provided is a hydrogen (or other propellant) tank in front, a heating element/pressure chamber in the middle, and the exhaust bell at the back.

I'm hoping you can perform the math needed to see if that configuration would deliver the 1000 tons of thrust I'm looking for.

Or 8 million Newtons if you prefer.

(th)

kbd512 · 2024-12-15 00:17:25

I'll describe what I was thinking of doing, even though it's very different than what GW was thinking of doing.

I used NERVA as my "how to build a solar thermal reactor" guide:
NUCLEAR THERMAL ROCKET/VEHICLE CHARACTERISTICS AND SENSITIVITY TRADES FOR NASA’s MARS DESIGN REFERENCE ARCHITECTURE (DRA) 5.0 STUDY

A NERVA-derived engine uses a "graphite matrix" material fuel element (FE) containing the U-235 fuel in the form of uranium-carbide (UC2) microspheres or as a dispersion of uranium and zirconium carbide (UC-ZrC) within the matrix material, referred to as "composite" fuel. The typical NERVA FE has a hexagonal cross section (~0.75" across the flats), is 52" long and produces ~1 megawatt of thermal power. Each FE has 19 axial coolant channels, which along with the element's exterior surfaces, are CVD coated with ZrC to reduce hydrogen erosion of the graphite. Composite fuel, with its higher exhaust temperature range (Tex ~2550-2800K), was the preferred fuel form at the end of Rover/NERVA program, and is used here. The performance characteristics for the 25klb-f NTR baselined in this study include: Tex ~2650–2700 K, p ch ~1000psi, ε ~300:1, and Isp ~900-910s. At Isp ~900s, the LH2 flow rate is ~12.6kg/s. The thrust-to-weight ratio for a dual TPA, expander cycle 25klb-f engine is ~3.43. The overall engine length is ~7.01m, which includes an ~2.16m long, retractable radiation-cooled nozzle skirt extension. The corresponding nozzle exit diameter is ~1.87m.

In the "Orbital Mechanics" thread, I described an engine primarily constructed of graphite (Carbon), generating about 1/30th the input thermal power and thrust of NERVA XE PRIME, with Hydrogen flow channels protected by Zirconium Carbide (ZrC), just as they were by the end of the NERVA program.

NRX A6 - November 1967
Avg Core Power: 1,199MWth
Tpropellant (chamber): 2,406K
Tpropellant (exit): 2,558K
Pchamber: 4,151kPa
Flow Rate: 32.7kg/s
Isp: 869s

NERVA XE PRIME - March 1969
Dry Mass: 18,144kg
Avg Core Power: 1,137MWth
Tpropellant (chamber): 2,267K
Tpropellant (exit): 2,400K
Pchamber: 3,806kPa
Flow Rate: 32.8kg/s
Isp: 841s
Thrust: 246,663N

My Solar Thermal Rocket (STR) engine uses a different heat transport mechanism because the thermal power is being dumped into the core via its exterior. I specified Supercritical Argon or Xenon for heat transport through the core.

Specific Heat Capacities of Hydrogen, Argon, Xenon, Graphite, Zirconium Carbide, and Tungsten
Hydrogen: 14,300J/kg°K
Argon: 312.2J/kg°K
Xenon: 158.32J/kg°K
Graphite (Carbon): 710J/kg°K
Zirconium Carbide: 334J/kg°K to 368J/kg°K
Tungsten: 134J/kg°K

At 175K, Hydrogen requires 13.02kJ/kg of thermal energy input to raise its temperature by 1K. At 2,700K, Hydrogen requires 18.06kJ/kg of thermal energy input to raise its temperature by 1K. Thus, the heat transfer rate is not a linear constant, between 20K and 2,750K. However, 14kJ/kg is close enough to gauge the thermal power that must be dumped into the Hydrogen to raise its temperature to the required value to produce the required exhaust velocity.

45.8X less thermal energy input is required to raise the temperature of Argon by 1°K, in comparison to Hydrogen, or 90.3X less for Xenon. Another way of looking at this is that the 40MW of thermalized input photonic power from the Sun will raise the temperature of 53.05kg of Argon from 393K (the ambient temperature in space at 1AU in full sunlight, or the temperature to which materials exposed to direct sunlight will increase to, above absolute zero), to 2,750K, given by:

39,039,000J is the heat transfer rate into the core from the solar array.

39,039,000J / ((2,750K - 393K) * 312.2J/kg of Argon) = 53.05kg of Argon
39,039,000J / ((2,750K - 393K) * 158.32J/kg of Xenon) = 104.62kg of Xenon
39,039,000J / ((2,750K - 393K) * 134J/kg of Tungsten) = 123.6kg of Tungsten

The supercritical Argon or Xenon will be contained in Tungsten heat pipes on its exterior, very similar in appearance to the KiloPower fission reactor. KiloPower used a lower temperature capability Iron-based superalloy that would melt long before achieving 2,750K, hence why I have specified Tungsten heat pipe tubing vs the Haynes superalloy used by the KiloPower demonstrator. The Tungsten heat pipes are filled with Argon or Xenon at supercritical pressures. The graphite core acts as a heat spreader device to increase the surface area in contact with the Hydrogen flowing through it. The Zirconium Carbide surface coating or cladding protects the graphite heat spreader elements from Hydrogen erosion. Since there is no nuclear fuel in my STR core, the thermal power density should be higher.

KiloPower Heat Pipes:

All that equipment you see the heat pipes leading to, above the core region, in the image shown above, is required to convert thermal power into electrical power using gas turbines. My core design doesn't have any of that equipment, meaning the heat pipes circulate Argon from the outside of the core, where they absorb heat from the concentrated sunlight impinging on them, to the inside of the core, where the thermal power is imparted into the Hydrogen and subsequently removed by the Hydrogen as it exits the core. This is effectively an inversion of the NERVA core design.

After the core has been heated to 2,750K by the concentrated sunlight it's bathed in, the mass of materials responsible for keeping the core temperature at 2,750K must be capable of replacing the heat dumped into the Hydrogen gas flow through the core, which removes heat at a rate of 39,039,000 Joules per second, given a 1kg/s flow rate, or else the core starts to cool down and propulsive efficiency is lost. This is in addition to the normal radiative heating loss to space. The STR core is being heated to the point that it's quite literally "glowing". The color temperature of an incandescent lightbulb is 3,000K for comparison purposes.

The materials used to construct the core can be both heated and cooled at a much faster rate than the Hydrogen propellant. This is a good thing, because the heat lost to the propellant must be replaced faster than it's removed. I specifically mentioned using supercritical Argon or Xenon as my thermal power transfer fluid for that reason.

NERVA's core flow velocity was approximately 130m/s, so for a similar-length core, we should expect similar heating rates, a similar chamber pressure, etc. The fuel element length was 1.32m and the fueled region was 0.91m in length. Since my core has a greater thermal power density owing to the fact that there is no Uranium in it, thermal power density is even higher.

GW seems worried about the solar concentration factor, but that's not an actual problem, except possibly for the design he came up with. I'm far more concerned about not melting the core, because whereas NERVA's core power density was 2-3MW/L thermal power density, in the STR design we have megawatts of power focused onto square centimeters of surface area.

At 1,000W/m^2, there is only 0.1W/cm^2. Most solar concentrator systems operate between 10,000X and 20,000X, with some as high as 30,000X. For 20,000X concentration, merely a "middle-of-the-road" system, that means the thermal flux is 2,000W/cm^2. A flight-weight prototype would be closer to 30,000X. NERVA was nominally 1.2GW core, so 1,200,000,000W divided by 3,000W/cm^2 is 400,000cm^2, or 40 square meters. A sphere 3.6m in diameter has a surface area of 40.715m^2. A sphere of that size made from pure Graphite would weigh about 54,967.5kg, although a lot of the core would need to be hollow in order for Hydrogen or any other gas to flow through it.

I'm not too worried about trying to match NERVA's core power density or flight weight because HEU is not available for civil applications. Whatever civilians could potentially achieve using HEU fueled NTRs is irrelevant to reality, because we're never getting any HEU. President Trump has stated that there will be no weapons grade nuclear materials used by our civil space program. If someone changes his thinking on this, then great, but there is zero political appetite for the use of weapons grade reactor fuels for civil applications, here in America or anywhere else. Certain qualified organizations may be able to obtain HALEU, perhaps suitable for NTRs, perhaps not. All NTR testing in America and Russia used HEU.

kbd512 · 2024-12-15 00:36:00

Solar Concentrator Design
As for the solar power collector design, I'm specifying 10m diameter parabolic dish concentrators used to couple the received photonic power into short fiber optic "pigtail" cables. The cables do not carry the concentrated photonic power all the way back to the reactor core, but they do de-couple the pointing of the solar concentrators dishes from their ability to point received power back at the reactor core, and only require a singular design regardless of distance from the reactor core. Therefore, the actual fiber optic cable lengths will only be sufficient to provide vehicle-concentrator-target independent pointing capabilities, in addition to initial solar power concentration from 1 Sun to 1,600 Suns. These pointable fiber optic "pigtails" create "hot spots" by focusing the power from the pigtail at a specific spot on the surface of the reactor core.

78.53982m * 1,224.9W/m^2 (at 1AU) = 96,203W per 10m diameter solar concentrator
96,203W * 416 concentrators = 40,020,448W of total input photonic power

All 416 concentrators will be arranged in concentric rings around the 10m diameter space tug Hydrogen tank.

Power Pointing Pig Tail Design
25mm diameter Silica-based fiber optic cable
2W/mm^2 is the input power limit for Silica-based fiber optic cable (higher concentration is achievable with shorter cable lengths)
490.87385cm surface area * 100,000cm (1km) length = 49,087,385cm^3 per 1km of 25mm thick fiber optic cable
49,087,385cm^3 * 2.2g/cm^3 = 107,992,247g = 107,992.247kg per linear kilometer of 25mm thick fiber optic cable
Edit: Pigtail mass should read 1,079.92247kg/km, NOT 107,992.247kg/km; decimal point mistake

Pig Tail Power Density:
96,203.646W from 10m concentrator / 0.049087385m^2 fiber optic cable surface area = 1,959,845W/m^2 or 1.959845W/mm^2

Initial Power Concentration:
1,959,845W/m^2 from 10m concentrator / 1224.9W/m^2 (1 "Sun") = 1,600 "Suns" of solar power concentration

416X "hot spots" are independently focused onto the reactor core, each with a power density of 195.9845W/cm^2

10m Diameter Parabolic Solar Concentrator Dish Arrangement
232m diameter outer circle, 10m diameter inner circle
Solar concentrator counts by ring position around the 10m diameter core stage:
1st - 6
2nd - 13
3rd - 19
4th - 25
5th - 31
6th - 38
7th - 44
8th - 50
9th - 57
10th - 63
11th - 69

Last edited by kbd512 (2024-12-15 01:29:26)

kbd512 · 2024-12-15 02:43:33

Pigtail Design Expansion #1
Each pigtail connects to a TIR (Total Internal Reflection) lens. Distance from the reactor core may or may not require different lens designs, in order to maintain a tightly focused beam of photonic power. Over the very short distances involved here, I would say that it's probably not required. To scale this system up to achieve substantially greater total core power, different TIR lens geometries will likely be required.

A TIR lens is an optical lens built on the principal of total internal reflection (TIR). TIR lenses collimate light, sending out a concentrated beam of full intensity. They are used in a wide variety of applications, including collimating the beams from high power LEDs.

MagLite TIR Lens

Theoretically, smaller TIR lenses of perhaps 1m to 2m in diameter could be used to increase packing density. This means the much larger and somewhat unwieldy 10m diameter parabolic dish concentrators could be replaced with a greater number of smaller TIR lenses to receive input power from the Sun, a short pigtail to concentrate and redirect power, with second smaller TIR lenses on the opposite end to further concentrate and direct the photonic power onto the reactor core.

Each 10m diameter parabolic dish concentrator couples its received photonic power into the pigtail, each pigtail independently focuses its concentrated power onto the core over a fairly short distance, and each pigtail is independently mechanically steered to deposit its "hot spot" onto a specific location around the circumference of the reactor core. The use of TIR lenses ensures that nearly all of the power is very tightly focused. It's not a laser beam, but well over 90% of the power. The TIR lenses could also further increase the concentration of the photonic power, if so desired or required. Each TIR lens must have a direct shot at the core, but that was the entire reason for using a fiber optic pigtail. Each parabolic dish can be moved independently of the vehicle it's attached to using its limited adjustment range, each pigtail has a far greater adjustment range, and if power is lost from a few of the concentrators, each hot spot can be readjusted to provide optimal overlap on the core.

ITV and STR Space Tug Vehicle Control Scheme
To keep the engine design as simple as possible, the engine will not gimbal. The entire vehicle's attitude will be adjusted by the considerable mass of the ITV's four habitation rings / reaction wheels, which provide gross X and Y pointing capability. Control in the Z plane, along the vehicle's direction of travel, is manipulated using thrust from the STR engine. When the STR Space Tug is detached from the ITV, its own onboard CMGs will provide X and Y pointing capability. The combination of the gigantic habitation ring reaction wheels up front and the considerable lever arm for the CMGs to act upon will provide gross and fine attitude control, respectively.

Design Imperatives
The major design goals here are to keep the parabolic dish array support structure and parabolic dish concentrators very light, and to keep the pigtails short since they get very heavy very quickly, especially when you displace the decimal point, as the math in my previous post shows, and to keep the core volume as low as practical so that it heats up to operating temperature very rapidly.

Solar Thermal Reactor Core Design
I need some expert advice on whether or not a graphite core is even necessary. Graphite in NERVA was used as a medium in which to deposit the Uranium fuel particles, as well as acting as a neutron moderator. I don't have either of those reqirements for a STR. However, graphite was also used to evenly distribute heat through the core. My initial thinking on the core design involved maximizing heat spreading to avoid core damage from hot spots, which proved troublesome during the NERVA program. There's enough photonic power being focused onto the surface of the core to rapidly melt most alternative materials. However, Tungsten is a notable exception with excellent thermal conductivity. To rapidly bring the core up to operating temperature, a pure Tungsten core with a Tungsten Carbide coating to resist erosion from the hot flowing Hydrogen may be substituted. Unfortunately, Tungsten is also a very heavy metal, so a Tungsten core would need to be kept very small, perhaps too small when compared to Graphite or other Carbon-based materials, such as Reinforced Carbon-Carbon (RCC) composite.

Graphite's tensile strength at room temperature is only around 5ksi, but rather interestingly, tensile strength doubles up by about 2,773K, then rapidly drops to zero as the material nears its sublimation point. If there's a way to properly seal the thermal power transfer channels within the core to prevent the Argon or Xenon from escaping, then the core and nozzle could be made from a monolithic material, such as RCC.

I don't know what will prove best. Tungsten, being a metal with good thermal conductivity and considerable tensile strength, even at 2,750K, would likely be far easier to fabricate than RCC. RCC is most notable for its thermal shock resistance. In-plane thermal conductivity can be even higher than Tungsten, but through-thickness thermal conductivity is rather poor, and is likely insufficient to permit rapid engine warm up. However, even if it proves fairly cheap to 3D print the Tungsten engine, I question whether or not the surface area will be sufficient.

Nozzle Design
NASA has conducted very recent testing of passively cooled RCC rocket engine nozzles for LOX/LH2 engines with excellent results. LOX/LH2 combustion temperatures reaches 2,985K, slightly hotter than the nominal 2,750K exhaust temperature from a NTR or STR. Radiative cooling of the nozzle was sufficient to permit multiple back-to-back engine runs with no repair or refurbishment between runs. Zirconium Carbide or other UHTC coatings may enable long duration firing of the engine without significant thermal damage or Hydrogen erosion. RCC is very light, at 1.96g/cm^3, making it an ideal nozzle material.

If there's a realistic way to 3D print most of the engine as a monolithic piece of material, from either RCC or Tungsten, then that would be most desirable. Despite the high cost of both materials, an engine that only flows 1kg/s is still tiny. RCC would be my preference because that minimizes weight and affords extreme thermal shock resistance. Carbon is ultimately easier to come by than Tungsten. However, I'm willing to use both materials. If Tungsten proves to be a better core material than RCC, for both absorbing heat and rapidly spreading it, then so be it.

kbd512 · 2024-12-15 03:48:09

Alternative Solar Array and Engine Configurations
It may be highly desirable, especially for very heavy vehicles with low acceleration rates, to use an asymmetric solar array mounted above or below the vehicle being accelerated. The primary reason has to do with optimization of the support structure that the concentrators / power collectors are mounted to, particularly the results of having a good number of them mounted too close to the engine core, resulting in the fiber optics having to adjust the output at unfavorable angles. It's still "doable", but you need longer pigtails or you have to use a non-planar array.

The above image shows the radar from the E-3 Sentry AWACS aircraft. Imagine for a moment that all those shiny radar emitter elements are solar concentrators. Said array could be side-mounted to the giant Hydrogen propellant tank and then the photonic power could be much more easily focused onto the engine.

Asymmetric Engine Core Geometry
Unlike a NTR, which virtually requires a symmetrical cylindrical core to achieve its power density, a STR core design could greatly benefit from being asymmetric, especially when used in conjunction with an asymmetric solar array.

Asymmetric turbulent flow resistojet:
Resistojet%201.png?width=903&name=Resistojet%201.png

Asymmetric turbulent flow resistojet test article:
Resistojet%20Hotfire%20Test.jpg?width=400&name=Resistojet%20Hotfire%20Test.jpg

The above image from Benchmark Space Systems shows a fairly new asymmetric resistojet engine design intended for use aboard micro satellites as an Isp upgrade from typical cold gas thrusters. Resistojets work on the principle of electrical heating of a propellant. The turbulent flow through its core enables the propellant to pick up more heat from the electrical heating elements over shorter distances. In this case, the scaling of the engine's input power and physical size precludes the use of a "straight through" laminar flow design, as shown in the left portion of the image for comparison purpose, because laminar flow has very poor thermal power transfer characteristics. What you're looking at is heat flux dumped into the propellant. The laminar flow design on the left does a relatively poor job when compared to the turbulent flow design on the right.

Latticed asymmetric resistojet thruster engine core design:
aerospace-11-00714-g003.png?1725245738

We can apply this same design concept to our STR's engine core to improve the heating rate of its Hydrogen propellant.

Edit:
Soviet / Cold War era efforts towards a flight-ready NTR design also employed turbulent flow, using twisted fuel elements, similar in appearance to a drill bit, to dump more heat into the Hydrogen propellant. The Soviet NTR engine design was likewise intended to support their own Mars exploration efforts.

1-s2.0-S100702140770038X-gr2.jpg

Similar engine solutions were arrived at by completely different interested parties (NASA and ROSCOSMOS in this case), because engineering solutions tend to converge on what the basic math and physics says will work, not necessarily because "one group copied the work of another". America and Russia both knew they needed high-Isp nuclear powered Hydrogen engines to undertake manned Mars missions in a practical way. That was the only tech sufficiently advanced at the time to do that.

Last edited by kbd512 (2024-12-15 15:05:07)

kbd512 · 2024-12-16 09:05:13

One of the principles employed by the optical pigtails at the center of each parabolic reflector dish, which is ultimately used to transmit power back to the solar thermal reactor, is that of the TIR (Total Internal Reflection) lens. A pair of TIR lens, one on each end of a short fiber optic cable, is used to first couple the photonic power from the reflector into the fiber optic pigtail, and then redirect its "hot spot" back onto the exterior of the solar thermal reactor core.

There are two different optical principles at play here. The first is reflection from the parabolic collector dishes. The second is refraction, which is what happens inside a TIR lens.

kbd512 · 2024-12-16 09:29:36

tahanson43206,

I found something very interesting last night that was, to me at least, quite astonishing. I had no earthly idea that such tech existed in a lab, let alone something that manufacturers are mass producing for industry. Apparently, we have flexible Silicone TIR lenses and even optical quality aerogels capable of acting as optical waveguides. I had no inkling that such tech existed, or that they were already commercialized products.

Flexible Silicone TIR Lenses:

The optical quality aerogels were developed by a pair of ladies working at MIT who were looking to use them in solar thermal power plants because the aerogel would be optically transparent to incoming photonic power from the mirrors, but would trap the heat inside a solar power tower.

MIT News - Making a remarkable material even better - Aerogels for solar devices and windows are more transparent than glass

This significantly alters the materials I would like to use, because you once asked me to come up with a kilometers-long collector array, so then I thought to myself... but how? How could I actually do that in a realistic way?

I guess we really can do this, and wrap the material around a core section (like new palm tree fronds / buds), so we would have a "solar tree" that collects the incoming light and runs it all the way back to the solar thermal reactor core. Anyway, this is a superior design my first thought about how to collect the photonic power, because it could be inflated using gas from the core stage and "unfurled", quite literally like palm fronds.

tahanson43206 · 2024-12-19 10:49:01

This post is intended to show a drawing attempt using Blender and a Wacom tablet.

The subject matter is kbd512's vision of a way of capturing solar energy in a plane of optical devices designed to feed photons into optical fiber cable.

If the vision is fully realized, the traditional cassegrain mirror concept will not be needed.

If the visions is fully realized, photons that arrive perpendicular to the plane will be deflected 90 degrees so they enter an optical fiber cable and proceed to a desired end point.

(th)

tahanson43206 · 2024-12-19 19:28:30

Here is an attempt to sketch what an individual optical bucket in an optical capture plane might look like...

Rendered in Blender using Wacom tablet - saved in Pinta as jpg and delivered via imgur.com

Note: This vision is aspirational. What kbd512 has shown us so far is what exists today, and is (apparently) in wide use.

Existing installations employ a solid light gathering device that delivers photons to a fiber optic cable that is connected to the base of the light gathering device. The 90 degree bend occurs in a section of the cable.

This implied one optical cable for each light gathering device.

The aspirational version shown above would incorporate the 90 degree bend into the light gathering device, and join the flow of photons so that only one optical fiber cable is needed per row in the platform.

(th)

tahanson43206 · Yesterday 22:12:29

The Blender default workspace color is dark, so that lines of various colors will stand out during design. I looked at changing colors, but decided there are too many factors to take into account for it to be worth while. Instead, I decided to investigate a program called Pinta, which is said to be similar to Paint for Microsoft computers. This is an early version of a drawing using Pinta.

The intent is to show in the simplest possible terms what an optical plane would look like, if such a thing is possible.

While the entire concept was inspired by work by kbd512 to design a solar powered propulsion system, it seems to me the concept would work on Earth as well as in space. Solar panels are planes that accept photon input and deliver electron flow. This concept, if realized, would consist of planes that accept photons and deliver thermal energy in a fluid.

It is not clear at this point if the materials needed to make such planes would be as common as silicon on Earth, or some other common material, but at this point it is not even clear it is possible. What ** is ** clear is that solid objects exist that can accept photons from the Sun and deliver them via fiber optical cable to destinations some distance away from the collection point.

(th)

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#1 2024-12-14 11:51:07

Focused Solar Power Propulsion

#2 2024-12-14 11:51:34

Re: Focused Solar Power Propulsion

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Re: Focused Solar Power Propulsion

#4 2024-12-14 15:19:49

Re: Focused Solar Power Propulsion

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Re: Focused Solar Power Propulsion

#6 2024-12-15 00:17:25

Re: Focused Solar Power Propulsion

#7 2024-12-15 00:36:00

Re: Focused Solar Power Propulsion

#8 2024-12-15 02:43:33

Re: Focused Solar Power Propulsion

#9 2024-12-15 03:48:09

Re: Focused Solar Power Propulsion

#10 2024-12-16 09:05:13

Re: Focused Solar Power Propulsion

#11 2024-12-16 09:29:36

Re: Focused Solar Power Propulsion

#12 2024-12-19 10:49:01

Re: Focused Solar Power Propulsion

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Re: Focused Solar Power Propulsion

#14 Yesterday 22:12:29

Re: Focused Solar Power Propulsion

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