Few Words On Hydrogen

Hydrogen is getting a lot attention on the last decades and it is promoted as the cleanest energy source. I would like to share my opinions on the topic. All energy sources require mining and refining procedures before being used. Among these energy sources coal was used for decades with minimal processing after excavation. Later came the crude oil. It required refining to be utilized. Then came the natural gas which required comparably less energy intense refining process. Compared to all these fuels, hydrogen cannot be found on earth in pure format. At the moment hydrogen is obtained from methane gas. Therefore, hydrogen generation requires one more step after natural gas production.

Energy by all means pollute the environment. For my point of view, the energy source which can be obtained with fewer steps and has the highest energy density is the best energy source. This valuation is valid for pure substances. Unfortunately, purification process is very expensive especially for some material. Compared to coal and gasoline, natural gas is the purest with minimal hazardous impurities. Therefore, its use is promoted. However, many countries do not have natural gas reserves. Trying to substitute it with hydrogen does not make much sense while it also relies on methane for production. More importantly, liquid hydrogen is less energy dense than liquid natural gas in terms of volume and is very difficult to store in liquid form. I recommend countries to invest on methane production facilities. Facilities that generate methane from coal instead of generating hydrogen from methane which is exported.

Water vapor is a more dangerous greenhouse gas than carbon dioxide. Then what is the point of using hydrogen instead of natural gas and gasoline. Energy source which requires less environmental pollution during mining and refining and has the highest energy density is the GREENEST fuel. Methane is an ideal energy source. The excess energy generated by the renewable energy sources can be used to produce methane from coal which is widely available world-wide. The cars, planes and rockets can operate with methane. Later when nuclear energy becomes the dominant energy source, it can be used to produce methane that can be used safely by the vehicles.

The World Is Betting On The Wrong Horse.

Liquid Air Plane - Final

I have previously written about the liquid air powered plane. It had a major flaw in the pressure chamber. Liquid air needs to be heated to ambient temperature very fast. This cannot be achieved with heatsinks. Instead heat pumps need to be used. The evaporator section of the heat pump should be embedded inside the aluminum payload fairing. Then, the compressor would pump the ambient air’s heat to the pressure chamber. Heat pumps are 300 – 400 % efficient. Additionally, the energy lost on the compressor mainly turns into heat which is also utilized by the pressure chamber. The more heat that can be transferred to the pressure chamber, higher the efficiency of the liquid air engine would be.

The main turbine of the liquid air engine would be powered by the pressure of the expending air. When the engine is cold, main turbine would be heated by electric to start the engine. Once the main turbine is operational, it would run the heat pump which would generate the necessary heat for the engine. Main turbine would also run the liquid air pump and the electric generator.

Main engine would be a pressure chamber which would be fed by liquid air and internally heated by the heat pump’s condenser. The rapidly expending gas would generate pressure and would be exhausted by the rotatable engine nozzles. In this design, the wings would be stationary on the fuselage of the plane and only the engine nozzles would rotate. The plane would not be a VTOL but a short takeoff and landing plane.

Direct Nuclear to Electric Conversion

I had previously proposed direct heat to electric conversion using a novel Thermoelectronic Energy Conversion method. This method can be enhanced to operate on radioactive materials as well.

My proposition is to generate high energy electrons using gamma rays and then store them. Most widely used gamma ray emitter is Cobalt 60. It converts the energy of fast neutrons to gamma rays. These gamma rays can be used to remove and accelerate the outermost electrons of Rubidium. I chose Rubidium due to its low work function (energy required to strip an electron). It is also more abundant than Cesium which has slightly lower work function. Additionally, Rubidium is a better electric conductor than Cesium. Rubidium has a very low density and has a very large atomic radius which is not ideal to stop gamma rays. Therefore, a lead layer would be used to stop the gamma rays to propagate further. Ideally, most of the gamma rays should be used to excite electrons not to excite the nucleus of an atom.

The excited electrons would be further accelerated by the high potential on the plate of the setup. Like in a pentode vacuum tube. The electrons will be collected on the collector of the setup. The collected electrons would then be pumped into capacitors using special charge pump circuitry so that the circuit would be completed. In order to maintain a potential difference between the rubidium emitter and the aluminum collector, aluminum oxide layer will be used. The thickness of the layer would be such that it would allow electrons with certain potential difference.

Space Zen

Recently there was an event on small satellites. As the size of a satellite decreases, it is much easier to deploy more of them to the orbit however they also lose some abilities of the bigger counterparts. I see people complain about space debris and in the meanwhile promote tiny satellites.

Here is my opinion on the topic; space is not a playground and not everyone should send a satellite. As the satellites get smaller, they lose the ability to deorbit themselves at the end of their life. They also lose some of the redundancies of the bigger counterparts. As a result, if something fails, they immediately become a space junk. There should be minimum requirements for a satellite to decrease space debris.

People are trying to obtain more and more data from space. Do we really need that much data, if we cannot take action related with them? There should be a sweet spot for that.

At the heart of Zen-inspired minimalism lies the concept of simplicity. This design approach emphasizes the removal of excess, clutter, and unnecessary ornamentation. By paring down one’s surroundings to the essential elements, a sense of tranquility and clarity is cultivated.

Tranquility of space requires Zen approach. Every satellite and constellation deployed to space should be well thought about.

Feasibility of a Liquid Air Powered Autonomous Truck

I had previously proposed liquid air powered autonomous cargo trucks that operate on a dedicated suspended bridge highway. Recently, I made some calculations on the feasibility of a liquid air powered vehicle based on the theoretical values with acceptable correction factors. The results look promising. I would like to repeat again that the performance of liquid air cannot beat a combustion engine. However, it performs better than battery operated alternatives.

Theoretical energy density of liquid nitrogen at atmospheric pressure and 27 °C ambient temperature is about 213 W·h/kg, while typically only 97 W·h/kg can be achieved under realistic circumstances. This compares with 100–250 W·h/kg for a lithium-ion battery and 3,000 W·h/kg for a gasoline combustion engine running at 28% thermal efficiency (Liquid nitrogen engine). Most notable advantage of liquid air is its Carnot efficiency. At 27 °C ambient temperature it is 74.3 %; at -16 °C ambient temperature it is 70 %. At such low temperatures, batteries have no chance and even diesel engines struggle to operate due to freezing of diesel.

I made my calculations for a full-sized container carrying truck. The weight of the truck with full fuel tank was 7300 kg (600kg fuel), the trailer was 6000 kg, the payload was 16,000 kg. I set the energy density of liquid air to be 1 / 20 of a diesel engine. In order to achieve half the range of a diesel truck it would require 6000 kg of liquid air. However, autonomous trucks have advantages in terms of weight because they can simply be a motorized trailer. Additionally, the cryogenic tanks can be designed to be used as the chassis. As a result, the liquid air powered autonomous container carrier can accommodate such a huge fuel tank with the same weight as a traditional truck with a trailer for half the range. One more advantage of such a huge fuel tank is, as it is depleted the truck gets much lighter compared to a diesel truck and its fuel consumption gets lower.

The prerequisites for this idea are light weight composite fuel tanks, light weight and high thermal conductive heat exchangers to create pressure that would turn the wheels. Aluminum alloy heat exchangers with carbon fiber can be a solution for that.

Ply Aluminum Storage

Wind energy is unpredictable and therefore require additional systems to meet the demand. Batteries are expensive and more importantly cannot handle so many charge recharge cycle. On the other hand, capacitors have much longer endurance. I would like to propose a simple capacitor design that can be used to store the excess energy of a wind turbine. It is just ply of aluminum and aluminum oxide. It is comparably easy to grow a thin layer of oxide over aluminum or remove the excess of it. They also form a very solid structure; higher strength compared to aluminum itself like the plywood.

Wind turbines require strong tower structures as a support. Ply aluminum capacitor can also meet this demand. A dual-purpose ply aluminum tower structure which doubles as a giant capacitor. Unlike batteries, this giant capacitor can be built to store high voltages. Therefore, it would be easy to charge them compared to complex balanced cell charging of batteries.

This technology can also be utilized on the construction of the buildings to compensate for the demand inequalities and to correct the power factor.

VTOL

I had previously proposed a VTOL design using liquid air. The same design can be implemented using rocket engines. Liquid propellant would generate more thrust and range compared to liquid air counterpart. At the moment there is no proper VTOL plane. Propeller powered ones lift off like a helicopter. Which has low lift capacity and very dependent on the elevation. Turbofan engines on the other hand are two heavy and thrust vectoring using nozzles produce inadequate takeoff thrust. When it comes to vertical takeoff nothing comes close to the rocket engines. They can takeoff at any altitude unlike helicopters and produce much more thrust than a turbofan. They are also much lighter compared to the thrust they produce.

My proposed plane will have four rocket engines on their sides and several (depends on the thrust requirement) engines on its bottom. Each side engine will be sandwiched between two wings for proper support and increased lift area. The wings and the nozzle of the rocket engine will be rotatable. This will allow all the engines to generate vertical thrust and vertically oriented wings to produce minimum drag while takeoff. The wings will be thin and flat with no curvature. The lift will be generated by the angle of attack of the wings. This slight orientation of the wings and the engine nozzles will generate lift. Multiple wings allow more even distribution of the load and reduce the stall speed of the plane. Additionally, the engines will have cascaded nozzles that I had proposed earlier. Together with low stall speed, the fuel consumption of the plane will be lowered.

The wings and the engine nozzle will be rotated by the directed exhaust gas of the engine. Therefore, there will be no need for high power heavy actuators for rotation. The payload fairing on top of the plane can accommodate military missiles as well as rockets for space. The rocket engines of the plane allow it to reach very high altitudes compared to traditional planes. This is beneficial for military defense while not many missiles can reach the plane. This is also beneficial for the space rockets while the rocket will not need to go through the dense atmosphere.

MIRV Defense System

A multiple independently targetable reentry vehicle (MIRV) is an exoatmospheric ballistic missile payload containing several warheads, each capable of being aimed to hit a different target. The introduction of MIRV led to a major change in the strategic balance. Previously, with one warhead per missile, it was conceivable that one could build a defense that used missiles to attack individual warheads. Any increase in missile fleet by the enemy could be countered by a similar increase in interceptors. With MIRV, a single new enemy missile meant that multiple interceptors would have to be built, meaning that it was much less expensive to increase the attack than the defense.

I would like to propose an economical defense system against MIRV attacks. It’s based on the fact that MIRVS are launched from a distant location than the defender missiles that need to travel less to defend. The idea is to utilize VTOL (Vertical Take-Off & Landing) or STOVL (Short Take-Off & Vertical Landing) cargo planes that can launch short range anti-ballistic missile. Ideally these planes would be unmanned and stay aloft for a longer period of time. Their fast maneuverability compared to land-based defense systems would allow them to locate themselves close to the direction of the attack. Therefore, the defensive missiles do not need to travel long distances. Additionally, anti-ballistic missiles can also have multiple defensive warheads to counteract the multiple heads of an offensive missile.

One final note, the anti-ballistic missiles can be powered by liquid propellant. This would enhance their range and even final speed. The unmanned cargo plane would also be powered by the same fuel as the rocket. Therefore, the missiles can be filled on demand from the large tanks of the plane depending on the range requirement like the naval powder bags.

High Bypass Cascaded Nozzle

I have previously proposed high bypass rocket nozzle designs. This one is a more refined version of them. The objective is to contribute the ambient air to thrust. My proposed design looks like a cascade fountain nozzle however extended more towards the rocket’s fuselage. Its perfect design should be iterated between the minimum drag and maximum additional thrust. This design reduces the dimension of the rocket’s main nozzle. The cascaded bypass nozzle also improves the stability of the rocket together with the support fins. The outer bypass nozzle does not need to withstand high temperatures while it would be isolated from the exhaust gas by the air cushion.

This design like all other nozzles would perform best at a specific flight speed range and altitude. Therefore, they would be designed specifically for every rocket or missile depending on their trajectory. High Bypass Nozzle would work wherever there is air such as Earth, Mars and Venus.

Orbital Transfer Vehicle

NASA has selected companies to study lower-cost ways to launch spacecraft to difficult-to-reach orbits. I would like to propose my own design based on my Mars Rocket Lower Stage idea. The idea is to utilize the high vapor pressure of carbon dioxide to attain high efficiency thrust using much simpler mechanisms. Unlike the Mars Lower Stage, the Orbital Transfer Vehicle will produce thrust in pulses.

The idea is very simple. Fill a cold pressure chamber with a predetermined amount of liquid carbon dioxide while the exhaust valve is closed. Then, close the input valve and start heating up the gas. When the pressure inside the pressure chamber reaches a certain pressure, open up the output valve which would generate the thrust. The output valve will remain open until the pressure inside the chamber drops to a certain level. Then, the output valve will be closed and the remaining gas will build up pressure again. This cycle will continue until the pressure drops considerably. Then, all remaining gas will be ejected. After that, new liquid carbon dioxide will be filled inside the chamber and the cycle will repeat. In classical liquid propulsion rockets, this process is continuous and turbopump are used to keep the pressure high and the heat is generated by combustion. This requires a complex and heavy engine. However, it may be enough to produce short powerful thrust pulses for some orbital transfers. Unlike ion thrusters, my method would produce very high thrust. For example, the combustion chamber of Raptor engine is 350 bar. If the pressure chamber of my proposal reaches those pressures, it may produce such high thrust for a short period of time. It is the most efficient way of turning the stored propellent into maximum thrust.

The heat source for my engine can be either solar panels or Plutonium 238. The liquid carbon dioxide can be pumped into the pressure chamber using an electric pump. Even pressure inside the propellent tank may be enough for pumping because the thrust is not continuous.

The overall objective of my idea is to store high density propellant, liquid carbon dioxide, inside a relatively light weight tank. Then release parts of this liquid as high-pressure gas in pulses. The temperature of the exhausted gas would be much lower than the liquid rockets. Therefore, aerospike nozzle can be utilized which saves a lot of space in vacuum. Maneuvering will be achieved by small side exhausts instead of gimbled nozzle. Simple design will reduce the failure rate for long missions and allow more room for the propellant.

Discussion on Nuclear Propulsion

When we need to apply one technology to another field. Too much reliance on experts kills the ideas instantly. I would like to support my thesis against the experts. The large distances in space requires more energy dense alternatives to current combustion-based propulsion. Nuclear is the most obvious alternative.

When I proposed to activate tiny nuclear bombs to generate energy pulses, the objection was that due to critical mass it wouldn’t work. A critical mass is a mass of fissile material that self-sustains a fission chain reaction. A steady rate of spontaneous fission causes a proportionally steady level of neutron activity. If the mass of the fissile material is below the critical mass, the reaction will die out; if it's above, the reaction will grow exponentially. As we all know the exponential growth produces a mushroom that ends the rocket and its surroundings. However, anything below that would die out while still producing energy in the meanwhile, E = mc². Even a tiny fraction of the fissile material is fissioned, the energy produced is way more than a complex turbopump combustion engine would produce. More importantly, the system would be less complex and scalable.

The energy by itself wouldn’t produce thrust. We need to accelerate material to achieve that. Gas is the most obvious solution. Liquified gas would be pressurized and expelled by the heat generated by tiny fission reactions.

This simpler rocket design should be implemented on the upper stages of a rocket, that would travel in space. This would generate much longer thrust necessary for planetary missions. More importantly, the planets or moons that have atmosphere can be used to refuel the rocket with much simpler mechanisms. This is a much feasible solution compared to propellent generation from ice. Heat dependent electrolysis process would take ages to fill up a tank. On the other hand, trying to liquify the air which is already very cold is a much simpler and fast solution.

Liquid Air Powered Ships

I had previously proposed ideas to use liquid air as a clean energy source alternative to some battery and hydrogen systems. I also had proposed ways to generate liquid air directly from the wind turbines.

Liquid air can be used as a direct propulsion for ships as well. Especially short-range ones. Liquid air at room temperature expends up to 700 times its liquid volume. This expansion can be used to propel a ship at sea. There is no need to use propellers. Jet stream of air would propel the ship silently. The lack of propellent noise is also environment friendly for the sea life. High thrust levels can also be achieved. The range would be limited but it would still beat the battery powered alternatives. Additionally, as the liquid air is consumed, the ship would get lighter. This is not the case with batteries. This design also allows high efficiency side thrusters for fast maneuvering.

This technology can be ideal applied to autonomous supply ships for islands. They would be refiled using the offshore wind farm. It would reduce the cost of supplying islands and produce no air, sea or noise pollution to the environment. Most importantly, it would require almost no exported raw materials to implement it.

Wind Breeders

Wind energy is the dominating renewable energy source. Unfortunately, its unpredictable nature requires supplementary energy sources. One way of balancing the supply and demand is to temporarily store the excess energy of a wind turbine. I would like to propose a new storage medium for this excess energy.

When we look at the energy densities of different materials, energy stored in fissile materials outnumber the rest by a giant margin. Unfortunately, and luckily, fissile materials found in nature are not easily fissile. They have to be in a certain isotope form. To overcome this problem breeder reactors were invented which create fissile material at a faster rate than it uses another fissile material as fuel.

My proposition is simple, but requires some serious R&D. Develop a new generation of wind turbines that are optimized for breeding none fissile materials into fissile ones by the kinetic energy of wind. Kinetic energy can be converted to electricity first and then this energy can be used to make the materials more fissile. Or much better, wind powered neutron emitter to convert Thorium 232 to Uranium 234 or even Uranium 235.

Such wind turbines can be build close to a reactor and supply the fuel or farmed offshore and harvested periodically. These turbines or farms would definitely require patrolling. Therefore, their numbers would be limited.

Ideas On Coal Power Plants

Chemically, the main composition of coal fly ash is amorphous-phase SiO2, Al2O3, CaO, Fe2O3, and FeO. Most of these materials have high hardness on Mohs scale. Therefore, they are used as cement additive. I would like to propose an enhancement to this idea; directly depositing these fly ashes into molded plastic. The flue gas of the coal plant can melt the raw plastic and deposit its content inside it. Leaving out colder gases and no ash. Some of these ash ingredients are already been used as plastic additives. For example: Hygroscope-P is Calcium Oxide in powder form, with a purity of 95%. The function of Hygroscope-P is to absorb moisture and eliminate moisture related problems in plastics and rubber applications. Silicon dioxide is a commonly used additive in plastic films to improve clarity, compressive strength, elasticity, and aging resistance. The molded plastic then can be used in construction. Unlike aerated concrete, this plastic would be much stronger and even replace concrete blocks to carry weight.

The coal plants also produce bottom ash. These ashes stick on the bottom of the furnace and buildup over time. It is difficult to remove them as well. I propose the bottom of the furnace to have a sheet of lead. As the furnace heat up this lead would melt and attract the bottom ashes inside the furnace. All the ashes would be much lighter than lead and float on top. As long as the furnace is heated, the bottom ashes can be collected over the sea of lead. Some of these bottom ashes can also be used as plastic additive. When the furnace is shot down, lead can easily be melted and removed from the bottom of the furnace. A typical coal plant furnace has a temperature higher than lead’s melting point and below lead’s boiling point.

I developed my idea after reading this article https://www.sciencedirect.com/topics/materials-science/coal-ash.

Scalability

I would like to summarize my previous statements and would like to point out why humanity stuck with the space race. During 1960’s companies with open checks from government developed powerful rocket engines. More than a half century later, a private company developed a much efficient but less powerful engine with a limited budget. Private and public institutes have different priorities. Expecting revolutionary designs from public sector is a dream. Space industry when it comes to deep space exploration is a money losing business which requires heavy government support like in 1960s.

Today, I thought of, how small a rocket that can deploy a tiny satellite to LEO can be. Liquid propulsion rockets are very efficient. However, they have pressurized tanks and heavy engines. These overhead weights restrict their minimum dimension. Then I thought about my carbon dioxide rocket with Pu 238 heater. That design can be scaled down considerable. If launched at cold temperature, the rocket shell can be made of thin plastic like in cola bottles. The majority of dry weight of the rocket would come from the propellant pump and Plutonium itself. The rocket would have a high propellant mass to dry weight ratio. Additionally, this design can be scaled up almost indefinitely.

I would like to make some comparisons here. The very first rocket V2 had only 15.5 bar of combustion pressure. It also used less efficient ethanol water mixture as fuel. However, it attaining an apogee of 176 kilometers with a single stage. On the other hand, todays much complex and efficient rockets can achieve more with less fuel. The problem with them is that they cannot be scaled down or up beyond certain limits due to cost and complexity. Within those limits, they are the best. However, huge distances of space require scalable solutions.

I would like to defend my stage zero design as well. Most objections come from the drag induced by multiple wings. Even AI things that way. The reason is that when they thing of a wing they thing of the wings used on current consumer planes. They are thick and have considerable drag. Therefore, multiplying their number would increase the drag further. However, my proposition is very thin flat profiles that generate lift by the angle of attack. It is the same principle with paper planes. Their wings are just thin and flat. However, the angle of attack during their launch generate lift with very minimal drag. Additionally, they can be quite strong for their thickness. Almost all the engineers working on aerospace industry had seen the planes as they are built now. Current established aviation firms take no risk and continue developing on the same design over and over again. Any new startup with such idea would receive minimal funding because the planes would not look fancy. As a result, humanity is spiraling on such designs. We need a propulsive maneuver like a trans-lunar injection to free our minds from the orbiting old designs in our heads.

AI Assisted Healthcare

Human body is a combination of complex subsystems. Almost everything is connected with everything. Unfortunately, medical doctors only have expertise in a single subsystem. As a result, some diseases take a long time for the real diagnosis. In worst case, the problem is related to several of the subsystems. In such cases, the patient is directed to different experts continuously like the bouncing ball in a pinball game. In pinball each bounce increases your point, but in healthcare it empties your pocket.

I am not a fan of AI in most fields. However, healthcare would definitely benefit from AI. AI with so much memory and broad knowledge, can see the big picture and diagnose the patient much earlier with fewer bounces.

Stage Zero Revisited

In my first book, I had proposed stage zero for a space rocket. After many design iterations, I am revisiting the idea again. This stage can easily be developed with current technologies. However, the stage is considered as a plane and therefore it is never build. However, it should be treated as a rocket with wings that flies at denser atmosphere.

It would run with the same fuel as the rocket itself. The oxidizer would be LOX. There are several options for its engine. It can be either a ramjet with LOX injectors or a simplified version of the rocket engine with high bypass enclosure. Designing a ramjet is much easier than a classical turbofan engine or a rocket engine. However, lower thrust would require more of these engines and larger propellant tanks. Unlike classical rockets, the atmosphere would be utilized during propulsion. It wouldn’t be as efficient as a turbofan engine, but would have much higher efficiency compared to a rocket engine. These engines will be supported by two wings, one at the top and one at the bottom. Multi-wings increase the lift of the stage zero and increases the strength of the engine housing. These wings together with the engines will be 90 degrees rotatable. This increases the thrust for takeoff and eliminates the need for ailerons. Stage zero will not fly at supersonic speeds. It will just climb. At higher altitudes more and more LOX will be used. Ambient heated air will provide additional thrust.

Stage zero would vertically takeoff and climb on a spiral route to the deployment altitude. The rocket would be housed inside a fairing to improve aerodynamics. At the deployment altitude, these fairings would open and the rocket would be released and fired. The objective of this stage is to launch the rocket at a much higher altitude. Therefore, the rocket wouldn’t need aerodynamic design details (no payload fairing) and all the engines can be vacuum optimized.

Companies have previously tried to launch a rocket from a plane. However, they are by no means close to my proposal. I propose a completely specialized rocket plane. Which is considerably different compared to a traditional cargo plane. It has multi-wings and special engines and the rocket is enclosed inside. Therefore, it should be mainly designed by rocket designers with collaboration with aeronautical engineers. Designing such stage would be much easier than designing a large first stage of a rocket. Additionally, this stage would consume less fuel compared to a rocket while it would have wings to support lift and high bypass engines for improved fuel consumption. Recovering stage zero would also be much easier due its wings compared to a very tall and thin first stage of a rocket. Finally, the rocket utilizing stage zero wouldn't need a launch platform. Horizontally assembled rocket can be launched horizontally.

Rover for Mars and Beyond

I had previously proposed a nuclear battery design that utilizes a radioactive material as heat source and carbon dioxide as the heat exchanger gas. The efficiency of this battery depends on the temperature difference between the warm and cold gas reservoir. Mars and other celestial bodies further away from the sun have very low surface temperatures. Ideal for the battery. I would like to propose a rover that utilizes this battery for surface exploration.

The rover will have two big wheels that is made of aluminum magnesium alloy for strength and heat conductivity. The wheels will be filled with carbon dioxide and serve as the cold reservoir for the nuclear battery. The wheels will be driven by the gas pressure generated between the warm and cold reservoirs. The rover will have all the controls and the warm reservoir in the middle section between the two wheels. There will be two arms attached to this middle section as well. These arms will also operate by the pressurized gas. They will be used to grab samples from the surface and most importantly assist the wheel during ascent or descent on the uneven terrain.

The mechanical sections of the rover will be directly powered by the pressurized gas. This will enable more efficient use of the nuclear energy, instead of converting kinetic energy to electricity and converting electricity into kinetic energy again. Only part of this energy will be used to generate electricity for the electronics and the sensors. The warm gas will also keep the sensitive equipment at the right temperature. Large wheels will allow the rover to advance faster on rugged terrain compared to multiple small ones.

Lunar Space Telescope

I would like to propose a space telescope to be deployed inside a crater at the south pole of the moon. There are regions on the pole that never see the sunlight. An ideal location for a space telescope. A surface mounted telescope is preferable compared to orbiting telescopes such as Hubble and James Webb that require continuous orbital adjustments and have limited fuel. The lunar telescope will be powered by the nuclear battery I proposed earlier. The continuous low temperature on the shadow region, improves the efficiency of the battery.

The telescope itself will be the payload bay of the rocket. Allowing larger diameter telescope. Once the telescope lands inside the crater, it will extend vertically like a zoom lens. The top fairing will accommodate mirrors and prisms to direct light from different directions to the vertical telescope assembly. Therefore, the telescope would not require bulky rotating mechanisms. The view inside a crater on the poles may be limited, but it would allow continuous observation without any disturbance by the sun.

Telescope will communicate with earth using the polar relay I proposed earlier.

Lunar Polar Relay

Lunar south pole is an attraction point for many researches. Some of these researches have to be conducted inside craters where earth communication would not be possible. I propose a lunar polar relay for this purpose.

The relay will be a lunar lander that lands on top of a hill that has good line of sight with earth. It will be powered by nuclear battery I had proposed earlier. It will use its top fairing as an antenna for earth communication and side fairings as antennas for lunar communication. This relay will allow continuous communication with earth unlike a satellite relay that has a certain communication window.

Citroën Landing Mechanism

Citroën DS using its “suspension oléopneumatique” can drive on 3 wheels. A hydropneumatic system combines the advantages of hydraulic systems and pneumatic systems so that gas absorbs excessive force and liquid in hydraulics directly transfers force. The suspension system usually features both self-leveling and driver-variable ride height, to provide extra clearance in rough terrain. I propose this technology to be adapted on future celestial body landers.

All celestial lander’s descent stage has propellant tank pressurizers. Some of these pressurized gases can be used for the hydropneumatic suspension. Additionally, I propose the lander’s landing gears to be spikes like bald eagle talons. We name the lander as “Eagle”, but then we place foot pads instead of talons.

The mechanism will work as follows. As the lander approaches the surface, it will 3d scan the terrain to spot the high and low spots. Then, based on the surface heights each spike’s suspension will be adjusted. For the sections that require more travel, the suspension will be softer. As a result, the lander will be able to land on a slope. The high strength spikes will penetrate the ground like an eagle’s talon and stabilize the lander on the surface.

Coandă Rocket Nozzle

I had previously proposed to utilize the ambient air to contribute to the thrust of a rocket like in turbofan engines. This would only work for the first stage of a rocket. My recent idea is a more realistic solution, to use Coandă effect.

The idea is to divert the air flowing around the rocket shell towards the nozzle. This would work for single nozzle rockets. For multiple nozzles the design would be more complicated and the effect would be less. The Coandă effect is the tendency of a fluid jet to stay attached to a surface of any form. Specially designed stepped layers would keep the air attached until the end of the nozzle. The diverted air would be heated with the exhaust gases and contribute to the thrust like in high bypass turbofan engines. The stepped layers can mostly be made of composite light materials. Only sections close to the nozzle need to withstand high temperatures.

Sherpa Rocket

I would like the combine some of my previous proposals into a mini rocket concept. It is a derivative of Hop on Hop off rocket I proposed earlier. The objective is to design a rocket that can refill its propellant tanks from the resources available on the celestial body the rocket is functioning at. A nuclear battery will be utilized for this purpose. The tanks may take weeks to be filled completely depending on the environment.

I named the rocket after the valuable people of Nepal, who did the hard work so that the explorers could concentrate on their scientific research. Commemorating “Tenzing Norgay”. The sherpa rocket would have four liquid rocket engines attached outside its shell. The rocket should need to generate enough thrust on takeoff with propellant tanks full and maximum payload. It would be a single stage rocket. Its main duty is to hand over the samples collected on the surface to an orbiting rocket which would take them back to earth. Once the handover is complete, sherpa would return back to the surface and start refilling its tanks before the next mission.

The payload bay will be at the top of the rocket. A crane inside the payload bay will retrieve the samples from the surface. An explorer robot will be used to search and collect samples. This robot will also load and unload the crane on the surface. The explorer robot will be carried to the celestial body with the very first mission. Earth transporter will also bring some items with every mission. So, the on-orbit hand over will be a two-way exchange.

Sherpa rocket will also be used to navigate on the celestial body. In that case the surface explorer will be retrieved to the payload bay and the rocket will fly to a new search area and land again. As a result, much larger area will be researched.

Solid Graphite Nozzles and Thrust Vectoring

Rocket nozzles is one of the most complex parts of a rocket. Especially when they need to warm the cryogenic propellant and have gimbal mechanisms attached on them. A pressure molded graphite nozzle is a good alternative but the design needs to be improved.

I propose the piping to be manufactured externally as a standalone design. Cavities can be made of plastic. Then, the graphite powder with some additional chemicals would be poured over these structures and pressure molded above them. Once the solid graphite block is ready, it would be heated to melt the plastic sections away. The metal piping would remain intact. This design allows propellant preheating on a solid block of graphite. Graphite is very strong, light weight and good conductor of heat which makes it a good nozzle material. The graphite block would cover the entire bottom of the rocket. This allows the thrust generated on nozzles to distribute evenly along the rocket bottom.

Some of the nozzles placed on the outer edge of the graphite block would have controlled inlet doors. These doors would be controlled remotely to allow some of the exhaust gas to escape from the side nozzles. These controlled exhaust vents would be used to maneuver the rocket, instead of the gimbal mechanisms.

Large Diameter Solid Booster

Solid boosters are high aspect ratio rockets strapped around a liquid rocket. There are several problems with this design. Strapping them around a rocket would increase the air drag. Additionally, a catastrophic failure of a strapped booster would ignite the liquid rocket which was the case with Space Shuttle Challenger disaster.

I propose the solid boosters to be added as the initial stages of a rocket. The idea came to my mind when I was thinking about the structure of a rocket. The bottom section of a rocket would carry all the weight of the rocket. Therefore, they have to be strongly build. This is the case with solid boosters as well. The walls of a booster need to withstand internal high pressure. As a result, the boosters placed at the bottom would support the weight of the rocket with no additional strengthening requirement. The highest thrust requirement of a rocket which is at takeoff would be delegated to boosters which they are good at. This reduces the maximum thrust requirement on the liquid propulsion engines.

Additionally, placing the boosters at the bottom reduces the possibility of an explosion to reach the liquid propulsion tanks at the top. An explosion would initiate the release mechanism of the stage below which would further decrease the possibility of a disaster.

The solid propellant will be separated by thin Tungsten walls because both sides of the wall will have similar pressure. The objective is to restrict the combustion volume of each section to balance the thrust among the sections. As a result, the solid booster will have multiple nozzles to generate more even thrust below the rocket. This will allow large diameter solid boosters.

Liquid Rocket Simplified Piping

Large diameter liquid propulsion rockets with small engines require so many rockets to generate the takeoff thrust. This makes the piping complex. I had previously proposed cascaded propellant tanks. This idea can be enhanced to solve two problems. I propose cascading multiple fuel and oxidizer tanks one after the other. Each engine would be placed on the boundary between the propellant and the oxidizer tanks. Therefore, the engine would be fed directly from the tanks with shortest possible piping. There would be no branching of pipes as well. These cascaded tanks would have thin separators while the pressure and temperature on both sides would be similar. These separators also support the dome of the propellant container which would be quite large in diameter. The cascaded tanks with same propellant will have connections between them to level out consumption differences.

Wind Liquid Air Generator

Classical wind turbines can be modified to liquify the air directly. At the moment all air liquifying solutions work with electricity. Using expensive electric generators and then converting electricity to mechanical energy again using expensive electric motors is not a cheap solution. More importantly this approach relies on exported materials. On the other hand, wind blowing on top of a wind turbine can be directly liquified using the kinetic energy of the wind. Liquifying process relies on compressors which can be driven directly by the wind turbine blades with an appropriate gear reduction ratio.

There would be a turbine blade like the one used on turbofan engines which would let the air blowing at the tower top to be pushed inside the liquefier system. Unlike plane engines, this process works at very low temperatures and the compressor blades can be made of cheaper material. The compressors that cool the air gets hot. They would be passively cooled by the blowing air by the heatsinks on top of the wind turbine. While the process’s speed relies on the speed of the wind, the cooling would also be stronger at higher speeds.

The tower of the wind turbine would house the liquid air and deionized water pipes. These two liquids would be stored at the bottom of the tower. The tanks also add weight and stability to the tower.

The objective of this design is to lower the cost of air liquification using direct use of renewable energy. More importantly, this approach requires almost no exported material in design allowing rapid and cheap deployment.

Liquid air, if produced by this approach would be the greenest fuel of them all. Additionally, liquified air can be used in the cold chain while the chilling process consumes a lot of power, liquid air is at -196°C.

Corrections on the Mars Human Flight

After thinking further on my human Mars flight concept, I found some parts that needed correction. The overall concept stays the same; use cheap scalable rocket design and fuel. The radioactive heater part of proposal needs to be revised. A nuclear submarine grade fuel needs to be used at least. The objective is not to fission all the fissile material in a blink of a second like in a bomb, but to generate much more heat per kilogram of weight. The energy requirement to generate thrust requires acceptable amount of fissile material. The first stage of the rocket would be recovered. Therefore, the radioactive material on the first stage can be recycled after recovery. The upper stages that fire above the Kármán line would have their radioactive parts melt down and dispersed on the atmosphere. Plutonium’s low melting temperature, 640 °C, helps with that. The rocket would be launched from the Nemo Point, which is already a space graveyard, a location far away from any habitat.

A second problem is the maximum speed at arrival to Mars. A fast speed requires a very low orbit. Mars’s atmosphere would generate a lot of drag in that case. Decelerating while approaching to Mars and accelerating during return would require additional stages which would make the rocket a giant at takeoff.

Mars stage would require modification as well. Even though it would be designed to accommodate a single crew standing. Reaching the fast-rotating service module would require a powerful rocket with multiple stages. In that case, the crew would need to use crane to descent on Mars and ascent back.

If the objective is to bring back sample to earth, it is much easier to use a humanoid robot for that. Sending a human just to grab several stones and bring him or her back alive would require an exponentially expensive mission. Sending a dead man on Mars on the other hand, is by no means a humanitarian achievement.

Nuclear Surveillance Plane

I had previously proposed a nuclear battery for space mission using Plutonium 238. It generates about 0.57 watts per gram. This heat energy can be efficiently converted to air pressure using carbon dioxide which has the highest vapor pressure. At its critical temperature of 31° C carbon dioxide can create pressure up to 73.8 bar. Plutonium’s heat would be enough to reach such temperatures. With these given, I would like to propose a surveillance plane that would be powered by Plutonium 238 and carbon dioxide gas turbine.

Closed looped pressurized carbon dioxide would be used to turn a turbine which would be attached to a propeller directly would create enough thrust for a surveillance plane to fly almost indefinitely. Directly driving the propeller, coupled with high efficiency carbon-dioxide based heat to kinetic conversion would make the design a feasible solution. A small coreless dc motor would be added to the turbine shaft to generate electricity for the electronics. The dc generator would be sealed inside the pressurized carbon dioxide chamber as well. This would simplify the design and any sparking would have no effect on the motor or the plane. The pressure would be generated by the temperature difference generated by the radioactive isotope and the ambient temperature; plane’s fuselage will be used for that.

Nuclear isotope does not generate so much heat. Adding high power electric generators and then using brushless motors with control electronics would reduce the efficiency of the system and the plane would not lift its own weight. In my design power demanding propeller is directly driven by the gas turbine. Only low power electric is generated for the electronics. Continues power supply eliminates the batteries.

As with all my plane designs, low speed high endurance plane will have multiple wings to be able to fly at higher altitudes with slow cruise speeds.

Command, Service & Mars Modules

Like Apollo spacecraft, the Mars spacecraft will also have service, command and Mars modules. These three will make up the very last stage of the rocket. Unlike Apollo, more stages of Mars rocket will accelerate final stage of the rocket to a much higher speed. The crew will be just two.

The objective of having multiple small modules on the last stage is to preserve the momentum of the last stage to enable the rocket return back with minimum additional thrust. Once approached to Mars, the last stage will orbit around the planet at a specific altitude to preserve its momentum. Then, Mars module will be released with a single crew. Mars module will utilize the same propulsion as the rest of the rocket. However, it will also have solid boosters strapped around it. During descent to the surface, only carbon dioxide engine will be used to slow down the rocket. Module’s large cross section and fin like small wings will generate drag on the atmosphere which would reduce the thrust requirement. Once the rocket lands on surface, the rockets turbopumps, which would operate with the temperature difference between the liquid carbon dioxide and the radioactive material, will operate with the temperature difference between the ambient air and the radiative material. This time turbopump will be used to liquify the ambient carbon dioxide. Very low ambient temperature on Mars surface will reduce the pressure requirement. While the propellent tank is refilled, the single crew will collect samples. Once the refill is complete, Mars module will takeoff from the surface. Strapped solid boosters will generate most of the thrust during takeoff. Consumed boosters will be ejected. With the aid of computers and crews on each side of the modules, Mars orbit rendezvous will be conducted. Then the crew on Mars module will be transferred with the samples to the service module. Unloaded Mars module will be ejected to the surface of Mars. With a perfect timing, the service module will fire its carbon dioxide engine for the Trans-Earth injection. When the service and command module approach Earth, the crew and the samples will be transferred to the command module. Again, with a perfect timing, the command module will be released from the service module to fall on Earth where it will be recovered from the sea.

Mars Rocket Lower Stages

Designing a warm gas propulsion rocket engine simplifies the engine and the propellant tank design. Carbon dioxide liquifies above 5.2 bar at −56.6 °C. Increasing the pressure would decrease the temperature. A propellant tank made of HDPE would easily satisfy these needs. HDPE is very cheap compared to traditional metals used on space rockets. It is also much lighter. It can easily be manufactured in large dimensions and welded continuously compared to the metal counterparts. More importantly the discarded rocket stages would completely decompose into carbon dioxide and water vapor during reentry. Low temperature nature of the design allows unibody plastic pressure chamber and nozzle. They can easily be molded and mass produced. I proposed a common nuclear waste, Strontium-90, to be used as the radioactive heater for the rocket engine. It would be used to heat the carbon dioxide to its critical point, 31 °C, for maximum pressure generation.

Traditional rockets have a very high aspect ratio due to their flight trajectory. I propose a direct ascent trajectory, which takes the rocket out of the atmosphere at relatively low speeds. This allows low aspect ratio designs with much larger base. This design reduces the thrust requirement for the first stage recovery. Much lower center of gravity also helps the stability of the rocket. An interesting bonus for the design is that, during reentry, air entering the combustion chamber of the unused engines would be heated by the radioactive heater and pushed back which would contribute to slowing of the rocket without any propellant consumption.

The solid boosters strapped to the first stage of the rocket would burn out very fast and drop back to the launch site from a relatively low altitude which can be slowed down by parachutes. Therefore, some of these boosters may be refurbished together with the first stage of the rocket. Unfortunately, upper stages of the rocket would not be recoverable. That’s the reason they would be made of plastic.

This rocket architecture allows highly scalable rocket designs with much lower build cost. It can be easily tested in smaller sizes and gradually expanded.

Liquid carbon dioxide for the rocket would be supplied from the thermal power stations which is a waste of those plants. The radioactive Strontium would be supplied from the nuclear power plants which is a waste of those plants. Strontium has a half-life of 29 years and emits beta particles. Therefore, some of it being dispersed to the atmosphere from the upper stages wouldn’t exhibit a major environmental hazard. As a result, this rocket would be one of the greenest of the rockets in operation.

Rocket for Human Mission to Mars

I am not a fan of sending humans to Mars when very capable robots exist for such tasks. Human mission requires several times larger rocket compared to a sample retriever robotic mission. The solution to a human mission is a scalable rocket design. A rocket with approximately the same dimensions as a lunar mission cannot achieve this. I opted for reduction in efficiency in order to scale up the design. The final design would be comparable in dimension with a tanker ship.

The rocket I propose will have 5 or more stages. Based on Saturn V rocket design, each stage’s gross mass is approximately 3.8 times its payload. Therefore, adding more stages to a rocket increases its gross mass exponentially. With my proposed rocket design this ratio may go lower. The rocket will generate thrust by carbon dioxide’s critical pressure. Liquid carbon dioxide will be warmed to its critical point, 31 °C, by the radioactive decay of nuclear waste Strontium-90. The rocket will not have a combustion chamber but a pressure chamber to generate thrust. The radioactive material with large surface area will be placed inside the pressure chamber to heat the pumped in liquid carbon dioxide. Carbon dioxide will be pumped at high pressure using turbopumps powered thermodynamically by the temperature difference between the liquid carbon dioxide and the decaying radioactive material. Low temperature operation will reduce the weight and cost of the engine and the nozzle. The propellant tank will also be lighter and cheaper than a liquid propulsion rocket’s tank.

Carbon dioxide has the highest vapor pressure of all the gasses. It has a critical temperature of 31° C and a critical pressure of 73.8 bar. Rocketdyne F-1 (Saturn V engine) has a chamber pressure of 70 bar and SpaceX Raptor engine has a chamber pressure of 350 bar. These numbers show that; engine efficiency is one think overall rocket performance is another. F1 engine completed many high-energy space missions successfully compared to more efficient counterpart which still has a long way to go.

My much simpler rocket design allows it to be built at much larger scales. It’s engine’s simplicity allows much larger engines to be build. Larger diameter would allow more engines to be placed on its bottom to increase the thrust. The first stage of the rocket will utilize additional solid boosters to assist take off. The rocket’s trajectory will be vertical to increase its distance from Earth as quickly as possible. Coupled with more stages, the rocket will achieve much higher speeds compared to Apollo missions. This will reduce the round-trip duration and increase the success rate of the mission.

I will discuss the details of the rocket and the Mars Stage on my next articles.

Nuclear Battery Design For Space

Current nuclear batteries generate electricity using Seebeck effect. This is a low efficiency way of converting heat into electricity with no moving parts. I propose a turbine electric generator to be used on the last stage of a deep space mission.

This last stage will be a liquid propulsion rocket. The propellant will be liquified methane and liquid oxygen. The heat source for the nuclear battery will be Plutonium 238, which is also used on other batteries. Pu 238 has a half-life of 87.7 years and generate 0.57 watts per gram. My design will utilize the expansion of methane gas to turn the electric generator. Methane is more efficient for this task than the water vapor and the turbine can operate at much lower temperatures. The outer shell of the rocket will be used as the cooler. The aluminum alloy outer shell will have fins to increase its infrared emission of heat to cool the methane gas to complete the cycle. This design would increase the energy generation efficiency of the nuclear battery above 50 percent compared to 5 percent for the current designs.

During rocket engine burning, the heat of the radioactive material can be used to preheat the liquid propellent as well. Continuous high-capacity electric generation would allow energy intense operations on the Moon, Mars and beyond. Solar panels cannot generate such energy far away from the sun. They also generate nothing on the shadows and at night.

Few Words for the Companies

Companies struggling with economic crises due to loss of business tend to cut the budget of cost centers. This includes operations and HR. Adjusting the capacity based on the demand is acceptable. However, from my observations finance institutes tend to cut more than adequate from their operations department. They keep spending on marketing and sales. Service sector generates value to their customer by the services they provide; this includes the operations as well. By lowering the budget of the operations, the head count would decrease and higher paid experienced employees would be replaced by cheap unqualified personal. This results in operational problems for the customer which reduces the companies added value. Some of the customers would leave and the remaining would only pay lower prices for the reduced service quality. This is a dead-end spiral. Spending millions on marketing and sales don’t solve such problems.

In service sector, if a business wants to stay in business, it has to keep its quality of service to a certain minimum. This can be achieved by experienced employees on the service side that are paid properly. Service side includes the operations obviously. Cost reduction can be achieved by automation. However, cutting budget from the inevitable manual work results in down spiral.

Additionally, the current employees of the company create value to the customer.  Employee selection and management is the most critical part of a company. Incompetent HR department due to budget cuts would change the employee profile of the company. Which results in a chaos for everyone within the company and the bad end would be inevitable.

The companies need to readjust their way of looking at their business. Cost centers vs revenue centers are a simple way of looking at the big picture. This narrow-minded approach results in big monetary losses and large firing moves by the companies. The big picture can be seen by looking at the value chain. As long as you create value to the customer you can make money.

Low Cost Stealth UAV

During disputes countries try to ramp up their military manufacturing capabilities with limited resources. I thought of a stealth UAV design that requires minimum export including the fuel. A liquid air powered plastic plane.

Liquid air when warmed to the ambient temperature expends 700 times from its liquid volume. This produces a rocket like thrust. Low temperature operation allows the fuselage and the wings of the plane to be made of clear HDPE plastic. Clear plastic filled with liquid air would be hard to identify from a distance. Combustion and propeller free propulsion allows silent operation. No heat signature on the exhaust and no radar reflection due to use of plastic. Liquid air cannot produce thrust for long time. The design of the plane would determine the range and speed of the plane. I propose eight flat wings to generate lift for the plane. The angle of attack would generate lift on the thin flat wings. The plane would be controlled by two ailerons placed on its back. The clear plastic fuselage and the fuel allow internal camera, RF and GPS antennas. Simple unibody design of the plane allows mass manufacturing using molds. HDPE becomes brittle at cryogenic temperatures. Therefore, the plane would need to be recycled and remolded again after several use. Liquid air leaves no residue hence the recycling wouldn’t require any chemicals.

The plane would take off by a small explosion inside the plane which would generate enough heat to expand enough liquid air to generate takeoff thrust. A tiny Li battery can be shorted for this purpose or a small charge can be fired.

Kamikaze version of the plane would be fueled by liquid air with higher oxygen concentration. Nitrogen would be still needed for stabilization. Once the plane reaches the target, a Li battery can be shorted to put the plane on fire or a small charge can be fired. Fuselage made of HDPE and liquid air would leave no contamination on the target zone after the fire.

Mineral Exploration Using Rovers

Mars Rovers over the decades have explored the surface of the red planet and supplied valuable information to earth. These robots are a kind of moving lab. They are light weight, reliable and operate with renewable energy supplies. An ideal autonomous mine explorer in the wild.

Mars Rovers, because of their use cases have demanding requirements which make them very expensive. However, a mineral explorer on earth wouldn’t have most of these requirements and therefore can be made much cheaper. More importantly mineral explorers would be mass produced unlike Mars explorers.

The light weight and sturdy design of the rovers allow them to be deployed by drones to remote locations. Unlike space rovers, the ones operating on earth can be supported by mobile telecom relays for high-speed communication. Allowing them to explore caves as well. Additionally, mobile renewable energy generators can be installed in the exploration zone to enable operation even in winter or at night.

Mineral exploration would increase the usage of the rovers and create a market for them. Which would attract high-tech companies to develop technologies for them. These technologies would then be transferred to space exploration.

The objective is to establish a two way now how transfer between deep space exploration and mineral exploration.

Construction on Mercury

When I saw the high Magnesium region on Mercury, the idea appeared on my mind. Using Magnesium and Silicon to construct on Mercury. The high Magnesium region has high magnesium and silicon concentration.

The melting point of Magnesium is 650 °C and the boiling point is 1091 °C.

The melting point of Silicon is 1,414 °C and the boiling point is 3265 °C.

The maximum temperature measured on the surface of Mercury is 430 °C.

These values indicate a straightforward approach to separate Magnesium from the ground and process it. The construction robot send to Mercury would be made of highly reflective material to stay cool from the heat of the sun. Due to lack of atmosphere, the places in shadow would stay cool. The construction robot would first find magnesium deposits with minimal impurities. Then using a special hot wire cutter, the robot would cut away a chunk of Magnesium. This process would be conducted when the sun is shining strong. The heat would already soften the low melting Magnesium. The wire cutter does not need to reach very high temperatures to cut away a Magnesium chunk.

The cut away chunk would then be shaped using the concentrated solar rays. Much stronger solar rays on Mercury compared to Earth would do the job quickly. The shaped parts would then be melted on the edges and merged.

Magnesium is a light weight and strong material. Very low concentrations of humidity and oxygen on Mercury would keep the material strong for a long duration.

The silicon deposits on the surface would also be processed like that to create glasses and insulators.

Non mechanical cut away and shaping process would allow a light weight and long-lasting construction compared to using drill bits and cutting wheels that would wear out quickly on other planets and moons.

By delegating the high energy part of a construction to the sun, a much simpler and low powered robot can be utilized for the construction. Which would mean low weight payload for the mission that would increase the feasibility of the idea.

Altitude Compensated Nozzle

The function of a rocket engine nozzle is to expand the hot engine exhaust gases down to ambient pressure, transforming thermal energy to directed kinetic energy in order to produce thrust. As the rocket ascents to the space the air pressure decreases. As a result, the exhaust gasses overexpand, reducing the effective thrust of the rocket. In order to compensate for the changing ambient pressure, the nozzle need to increase its expansion area.

I thought of a solution which may not work but comparably easy to implement. For the solid booster rocket I proposed earlier, the nozzle does not need to have propellent heat exchangers attached on it. This simplifies the design. A nozzle made of high temperature resistant tungsten alloy would be enough. I propose the nozzle to have multiple sections stacked on top of each other. These stacks will hold in place with a low melting metal such as aluminum alloy. Tungsten is not a good conductor of heat compared to aluminum. As the nozzle heats up, each low melting section will melt away and drop the next nozzle section into place. The thickness of the nozzle section holders would be altered to achieve the adequate delay between each nozzle section drop.

This would be a light weight and zero mechanics solution to altitude compensated nozzle design for solid boosters.

Solid Booster Revisited

I had previously proposed a deep space propulsion system. I improved the design so that it can be used both on the first and the second stages of a rocket as well.

The solid booster would be composed of three sections.

The booster section where the solid propellent is burned and the thrust is generated. This section needs to withstand high temperature and pressure.

The transfer section where the stacked solid propellant is transferred to the booster section. This section should have enough opening to allow the booster section doors to open. This section needs to withstand moderately high temperatures and pressures because the new propellant block needs to be transferred to the booster section while it is still hot and has some pressure.

The storage section where the stacked propellant is stored. This section has no particular temperature and pressure requirement.

The solid booster will fire when the storage section is full and the booster section is loaded with a propellant block. Once the solid propellant inside the booster section is consumed, the booster section doors will open. Then the release latch will be opened to release a propellant block into the booster section. After that the booster section doors will close and the rocket will be fired once more. Finally, the release latch will be closed and the holder latch will be opened to allow the remaining blocks to slide down.

The solid propellant blocks will be molded inside a plastic shell like HDPE. This will allow them to slide down more easily and prevent cracks to the solid blocks. HDPE burns out completely into carbon dioxide and water vapor which would contribute to thrust as well. The solid blocks will have different grain geometries and height to suit to the thrust need. The initially fired block will be optimized for high peak thrust and short burn time to allow takeoff. As the rocket gets lighter, the grain geometry will allow more burn time and lower peak thrust.

The solid boosters require strong shells that are heavy. By shrinking the booster section, the weight saving would be high. Additionally, as the propellent is consumed inside the booster, the thrust goes down due to increased combustion volume due to the void of the consumed fuel. Burning propellant in sections and keeping the combustion volume small increases the efficiency of the rocket.