Wednesday, November 28, 2018

Mitigating Forest Fires by Harvesting Potentially Hazardous Woodland Biomass for the Production of Renewable Methanol

California Fires 2018 (Credit: David McNew/Getty)


 by Marcel F. Williams

California's forest, woodland areas, and its nearby residents are the latest victims of climate change as the world's fossil fuel dominated energy economy continues to increase greenhouse gasses in the Earth's atmosphere to dangerous levels.   

The state of California has 33 million acres of forest land.  Less than 400,000 of that acreage  burned in California from 1980 to 1990.  But just last year, 1.4 million acres burned in California. And so far this year, 1.8 million acres of California land has  burned.

Why?

California has grown 3 degrees warmer during the autumn seasons over the past 40 years while rainfall in the state has decreased by about one third during the same  period of time.

The  Federal government owns about 57% of the woodlands in California. Privately owned forest accounts for about 40% of California's woodland areas. But the State of California only owns about 3% of Califorinia's forest.

It is currently estimated that California's woodland areas have approximately 129 million dead trees. . Ironically, removing dead trees actually enables the spread of grasses and combustible weeds that make forest more likely to burn. Dry kindling, brush, bushes and twigs are the principal catalyst for the rapid spread of wildfires. So such vegetation also has to be safely managed.

Some of the worst forest fires in California have been caused by power lines. This has prompted some in the state to suggest burying power lines that transverse forested areas. But their are more than 176,000 miles of power lines in California. And putting power lines underground would cost ten times as much as stringing them on poles.

Controlled burning of woodland vegetation has long been a method for fire mitigation since before the arrival of Europeans in North America. But  burning  woodland vegetation would increase the amount of excess carbon dioxide put into the Earth's atmosphere, exacerbating the problem of rising temperatures that have helped to enhance the fire danger in California in the first place.

But  there is an alternative solution that could make the mitigation of forest fires  in California economically sustainable while also reducing California's dependence on fossil fuels. And such measures cold eventually lead California's energy production and use becoming completely carbon neutral.   And all it would  take would be for two legislative measures to pass within the State of California. 

Its my view that the State government in California should pass legislation that:

1. Mandates that  all utilities producing electricity within the State of   California  produce at least 5% of that electricity  for their customers by using-- bio-methanol-- directly derived  from  the dead trees and potentially dangerous woodland biomass in California’s forest and wooded residential areas by the year 2025 and up to  10% by the year 2030

and 

2. Requires all gasoline sold in California to contain at least 5%-- bio-gasoline-- synthesized from bio-methanol that is directly derived from the dead trees and potentially dangerous woodland vegetation in California's forest and wooded residential areas by the year 2025 and up to 10% by the year 2030.

That's it! 

Methanol electric power plant at Point Lisas, Trinidad (Credit: Mendenhall Technical Services)

Approximately 33% of the electricity produced in California is generated by natural gas power plants. About 53% of California's electric power is produced by carbon neutral renewable and nuclear power energy sources.

Its neither difficult nor exorbitantly expensive to modify an existing natural gas electric power plant  to use methanol instead of natural gas. Additionally,  methanol electric power plants would have a higher electric power output than burning natural gas thanks to wood alcohol's  low heating value, low lubricity, and low flash point. 


Gasoline can be blended with methanol up to 15% without any modifications to an automobile. But 
energy companies have been able to synthesize  methanol directly  into high octane gasoline since the 1970s. And this would allow any level of mixing with gasoline from petroleum. In theory, you could have gasoline that is 80% derived from bio-methanol and 10% from petroleum with the remaining 10% of the fuel being composed of ethanol. Such an automotive fuel would be-- 90% derived-- from renewable biomass, reducing the utilization of gasoline from oil by 90%.

Any increases in the cost of gasoline containing bio-gasoline from bio-methanol could encourage Californians to purchase more fuel efficient electric and plug-in-hybrid electric vehicles. But a vehicle fuel mix of 10% ethanol (Federally mandated), 10%  gasoline from bio-methanol, and 80% gasoline from petroleum could substantially reduce oil demand, possibly mitigating any additional cost related to a mandated use of 10% bio-gasoline.

Methanol could also be directly used in high fuel efficiency hybrid fuel cell vehicles. Using methanol directly in automobiles would, of course, be cheaper than converting methanol into gasoline. Bio-methanol derived from California's forest could also be used to produce biodiesel.

There is also a growing global interest in using methanol to power sea vessels. Methanol powered ships would be cleaner and bio-methanol ships  with no sulfur emissions and  lower nitrogen oxide emissions relative to current marine vessels powered by fuels synthesized from petroleum. Marine methanol ferries are already operating between Sweden and Germany.

Legislation mandating the use of bio-methanol from California's forest should provide a strong economic incentive for energy companies selling electricity and gasoline in California to hire forest workers to aggressively harvest dead trees and other potentially dangerous woodland vegetation from California forest and residential woodland areas for conversion into methanol. This should substantially reduce  the level of fire  danger in California's woodland areas while also reducing the amount of CO2 put into the atmosphere as the result of the reduction in forest fire and forest fire intensity.  

Beyond the reduction in fire danger,  hiring people to harvest potentially dangerous woodland biomass  should have a  positive economic impact for nearby residential communities.  Converting at least 10% of the  natural gas power plants in California for methanol utilization should also have some positive economic impact for communities near such energy producing facilities.   And the deployment of  pyrolysis and synthesis facilities designed to convert biomass into methanol within  California should have positive economic impact for the entire state.


Notional Flying Whale airship (Credit: Flying Whales)

The enhanced harvesting of dead trees and potentially dangerous woodland vegetation from remote forest might also encourage energy companies within  California  to utilize the next generation of airship technology. And airships might also greatly enhance the ability of the State of California and the US Federal government to fight fires in California's forest.

Airships being developed by the French company, Flying Whales, are being designed to transport up to 60 tonnes of lumbar within forested areas. Such airship technology could obviously be of use in California for removing the hundreds of dead trees that currently exist in California forest.

Lockheed Martin, on the other hand,  is developing an airship that could transporting payloads up to 20 tonnes in mass within a large cargo bay.  Forest kindling, grass,  bushes, twigs and other potentially dangerous vegetation could be removed from California forest by Lockheed Martin's airships.
 
Similar airship technology could also be used by the State and Federal government to fight forest fires,  dousing woodland fires and residential areas near forest with tonnes of water routinely retrieved from nearby lakes. The Lockheed Martin airships could also be used to rescue residents and fire fighters that might be trapped by raging forest fires.

The aggressive utilization of   airship technology in California could help California businesses to lead the US and the world in  the new age of airships. And, in theory,  such airships could be fueled with dimethyl ether, derived from methanol derived from California's forest  my modifying the diesel engines to use dimethyl ether.

Lockheed Martin airship (Credit: Lockheed Martin)

The introduction of a methanol economy into California could also enhance the ability of the state to become-- completely carbon neutral by mid century. This, however,  would require the production of hydrogen through renewable or nuclear resources--  or a combination of both. Hydrogen could be used to synthesize methanol from wasted CO2 from the pyrolysis of urban and rural biomass  and from the  CO2 waste from the flu gasses of methanol electric power plants.

For California to be completely carbon neutral, all of the natural gas electric power plants in California would have to be converted into methanol power plants. The gradual  conversion of electric power production from natural gas to renewable methanol would make California carbon negative during the transition from fossil fuels to renewable biomass,  with more CO2 being extracted from the Earth's atmosphere  than being returned to the atmosphere. However, once all fossil fuel power plants have been replaced by methanol power plants that recycle CO2 from methanol synthesis and flu gas, then electric energy production and consumption in California would be carbon neutral.

Synthesis of renewable methanol from biomass.

Hydrogen in California could be produced from large solar or nuclear facilities located near biomass pyrolysis plants and methanol electric power plants. Alternatively, such facilities located near California coastlines could liquefy the carbon dioxide, exporting the CO2 by tankers to remote ocean nuclear power or renewable (floating wind, solar, or OTEC) facilities  in remote US territorial waters where methanol and other renewable synthetic fuels could be safely manufactured.  The Exclusive Economic Zones (EEZ) surrounding remote island territories such as: Wake Island, Howland Island, Baker Island, Johnston Atoll, Jarvis Island, etc. could be regions where floating vessels could use carbon neutral energy sources to produce methanol, jet fuel, dimethyl ether, gasoline and diesel fuel far away from urban populations.  Methanol could then be shipped by methanol powered tankers back to the California coastline to fuel its methanol electric power plants or for conversion into renewable gasoline. 

But once the transition from fossil fuels is complete, California energy production and consumption would be carbon neutral. Eventually,  California will have a shortage of bio-carbon resources for its energy economy which would require the extraction of additional CO2 directly from the atmosphere or from seawater or both. 



Links and References


 
Senate Passes Legislative Packagein Response to Wildfire Danger 

Thinning California's fire-proneforests: 5 things to know aslawmakers move toward a plan 
What fire researchers learnedfrom California’s blazes


 Methanol for Power Generation
Methanol as a Low Cost Alternative Fuel for Emission Reduction in Gas Turbines
Methanol - Gaining Twice: Improving Both the Quality of Air as well as Providing a Reliable Electricity Supply

Renewable Methanol as Liquid Electricity

The Methanol Alternative: 2012 Methanol Forum

The Production and Utilization of Renewable Methanol in a Nuclear Economy

Methanol Fuel Blending

The Production of Bio-Methanol

The rise, rise, rise of bio-methanol for fuels and chemical markets

In France, whales soon will fly

Lockheed Martin LMH-1 (P-791)


Monday, October 22, 2018

Evaluating Lockheed Martin's Reusable Lunar Lander and Orbital Propellant Depot Concept

Notional  reusable lunar landing spacecraft on the lunar surface (Credit: Lockheed Martin)

by  Marcel F. Williams 

At the 69th International Astronautical Congress held in Bremen, Germany this month,  Lockheed Martin  unveiled a new reusable lunar crew lander concept.

For simplicity,  I'll designate the notional Lockheed Martin spacecraft discussed in this article as the R-LL (Reusable Lunar Lander).   According to Lockheed Martin, the R-LL will have dry weight of 22 tonnes and be capable of storing up to 40 tonnes of LOX/LH2 propellant. The R-LL will have up to 5 km/s of  delta-v capability.

Lockheed Martin argues that the R-LL should be capable of crewed round trip  missions to any area of  the lunar surface from NASA's future Deep Space Gateway (DSG) which is to be located at a Near Rectilinear Halo Orbit (NRHO).    Such round trip missions, they argue,  would also be capable of delivering up to one tone of payload to the lunar surface in addition to a crew of four individual astronauts. 



While Lockheed Martin has been rather vague about the exact dimensions of the R-LL, they have indicated that it will consist of only two cryotanks and will be derived from the Centaur upper stage family and its descendants. They also suggest that the R-LL will have a diameter close to that of  the future Orion spacecraft.

Since Lockheed Martin's Centaur V is currently in development as the future upper stage for the ULA's future 5.4 meter in diameter Vulcan rocket, one might speculate that the diameter of the R-LL cryotanks might be the same as  and  is supposed to have the same 5.4 meter diameter as the Centaur V. Such large diameter liquid hydrogen and liquid oxygen tanks should be capable of easily accommodating the 40 tonnes of propellant required for the R-LL. So deriving the lunar vehicle from the Centaur V cryotanks might be the simplest and cheapest path towards rapidly developing the R-LL.

Lockheed Martin's Notional  Reusable Crewed  Lunar Landing Vehicle

Propellant: 40 tonnes of LOX/LH2

Inert Weight: 22 tonnes

Engines: Four RL-10 derived engines

Maximum delta-v capability: 5.0 km/s

Maximum number of crew: Four

Additional cargo capability: one tonne of additional cargo
The R-LL would use four engines to provide engine out capability. This would enhance crew safety during attempted landings in case of a serious malfunction with one of its engines. So just two counter balancing engines could be used during a landing in case of single malfunction engine.     Lockheed Martin says that engines for the R-LL  would be derived from  Aerojet Rocketdyne's  RL-10 family or from Blue Origins restartable BE-3 engine. Aerojet Rocketdyne's RL-10 derived CECE engines would be  capable of at least 50 restarts with a throttling range from 104 percent to  just eight percent of thrust. 

Departing from the Deep Space Gateway, it would take approximately 12 hours for the R-LL to reach any point on the lunar surface. Another 12 hours would be required for the R-LL to return to the  gateway at NRHO.

NRHO: (Near Rectilinear Halo Orbit):

Travel time to and  from LEO:~5 days from LEO (3.95 km/s)

Station keeping: 5 m/s per year

Travel time to and from LLO:~ 12 hours to LLO (0.730 km/s)

Lockheed Martin says that their notional lunar spacecraft would be capable of accommodating  a crew of four astronauts on the lunar surface for up to two weeks. Such a lengthy stay would require at least four tonnes of additional shielding mass to protect astronauts from the inherently  deleterious heavy nuclei component of cosmic radiation and from a major solar flare. So one would assume that such enhanced radiation shielding would be part of the notional space vehicle's 22 tonnes of inert mass.

Lockheed Martin has also suggest that propellant depots could be co-orbited with the Deep Space Gateway so that the R-LL can be refueled at NRHO.

The simplest propellant depots would probably have to be utilized within a month after deployment to NRHO since approximately 3.81% of its liquid hydrogen and 0.49% of its liquid oxygen would boil off within a months time. For the 40 tonne LOX/LH2 requirement for the R-LL, such propellant depots would probably have to NRHO by the SLS or the BFR.

More sophisticated propellant depots could be equipped with cryocoolers and solar arrays capable of re-liquefying fuel boil-off.  Ullage gases from the boil-off of liquid hydrogen could be used to re-liquefy gaseous oxygen while 12 to 15 kWh of electricity would be needed to liquefy one kilogram of gaseous hydrogen. The 5.7 tonnes of liquid hydrogen required for a lunar mission would lose more than 217 kilograms of LH2 per month (7.2 kilograms per day).  But a 10 kWe solar  array deployed to NRHO capable of producing more than  240 kWh of electricity per day would be capable of re-liquefying 16 to 20 kilograms of LH2 per day.  The solar arrays for the Orion spacecraft will be capable of producing more than 11  kW of electric power. So it should be rather simple to deploy propellant depots already equipped with cryocoolers and and solar panels in order to prevent fuel boil-off. 

Solar powered depots that simply re-liquefied its ullage gases and powered pumps for storing and transferring liquid fueles would only  require the continuous delivery of liquid hydrogen and liquid oxygen.  Future Vulcan Heavy/Centaur rocket could deliver 7.3 tonnes of liquid hydrogen or oxygen to NRHO per launch. Monthly launches could deliver more than 87 tonnes of propellant to depots located at NRHO per year, more than enough for two R-LL missions to the lunar surface per year.

Notional propellant producing water depot (Credit: Lockheed Martin)
The most technologically complex propellant depots could use solar power to  actually  produce liquid hydrogen and liquid oxygen directly from water. This would require the addition of an electrolysis plant plus substantially more solar power.  A 375 KWE solar array proposed by Lockheed Martin could produce 40 tonnes of liquid hydrogen and oxygen propellant at NRHO per month. Such huge 375 KWE solar arrays would weigh  less than four tonnes. And two such arrays could be directly delivered to NRHO with a single SLS launch. But much smaller commercial launch vehicles could deploy 300 KWe arrays to LEO for later transport to NRHO by fueled upper stages deployed to LEO. 300 KWE arrays at NRHO could produce 40 tonnes of propellant in five or six weeks rather than just four weeks for the larger arrays.

Solar powered propellant producing water depots would make it much simpler and safer for commercial rockets to deliver fuel to NRHO since the payload would only be water. Propellant producing water depots at NRHO could eventually be supplied with water from the lunar poles.

Of course, water and propellant being produced on the lunar surface itself would dramatically reduce the amount of propellant required for   R-LL departures from NRHO. Reusable tanker vehicles directly derived from the R-LL could deliver more than 40 tonnes of lunar water  to propellant producing water depots at  NRHO per flight.  Just 12 round trips from the lunar surface could deliver enough water to NRHO to manufacture enough fuel for crewed missions to the orbits of Mars or Venus.

Lockheed Martin envisions that astronauts would be deployed to the NRHO gateway via the Orion and the Space Launch System. And then the would take the R-LL to the lunar surface and back to the NRHO gateway. And then they would take the Orion back to Earth.

However, propellant depots deployed at LEO  would make SLS crew launches of the Orion vehicle obsolete.  Refueling at LEO, the R-LL would have more than enough delta-v capability to transport crews from LEO to the  NRHO gateway. And refueling at NRHO, the R-LL would, of course, be capable of returning crews from NRHO back to LEO.  And even with  22 tonne of inert weight, a  5.4 meter in diameter R-LL could be launched to Leo aboard a Vulcan/Centaur launch vehicle within  a  6.4 meter in diameter payload fairing.

So for trips to the lunar surface, astronauts would simply take a Commercial Crew Launch vehicle (Falcon9/Dragon or Vulcan/Centaur/CST-100) to a commercial space habitat at LEO where a propellant depot refueled R-LL was already docked and ready to be boarded.  The R-LL would leave LEO with enough  propellant to take its crew on a 5 day journey to the NRHO gateway where another already depot fueled R-LL would already be docked.  The second R-LL  would take the crew for a round trip to the lunar surface, 12 hours to reach the surface and 12 hours to return to astronauts to the Deep Space Gateway.  The astronauts would return to the gateway with the first R-LL already fueled for their return to a commercial space station at LEO. The Crew would than take a Dragon or CST-100 Starliner back to the Earth's surface.

Such an architecture would, finally,  allow the SLS to be used--exclusively-- as a super heavy lift cargo transport. Such payloads could include: large and spacious microgravity and artificial gravity habitats derived from SLS propellant tank technology,  large water and propellant depots derived from SLS propellant tank technology, interplanetary spacecraft capable of accommodating at least 400 tonnes of propellant derived from SLS propellant tank technology for crewed missions to the orbits of Mars and Venus, 8 meter in diameter space telescopes exceeding the capability of the James Webb telescope,  and large inflatable microgravity and surface habitats that could make it a lot more spacious and comfortable for future astronauts and tourist to live under artificial gravity conditions in space or on the hypogravity surfaces of the Moon and Mars.


Links and References

Concept for a Crewed Lunar Lander Operating from the Lunar Orbiting Platform Gateway

Lockheed Martin unveils lunar lander concept

Cis-Lunar Gateways and the Advantages of Near Rectilinear Orbits

Lockheed Martin's Reusable Extraterrestrial Landing Vehicle Concept for the Moon and Mars





Thursday, August 23, 2018

Utilizing the Phantom Express to Supply Water to Propellant Producing Orbital Depots

Artist rendition of a suborbital  Phantom Express with side mounted payload rocket (Credit: Boeing Aerospace)

During a recent 10 day testing period, Aerojet Rocketdyne  successfully hot-fired its new Space Shuttle Main Engine (SSME) derived  rocket engine-- the AR-22. The Sacramento, California headquartered company successfully demonstrated that the  AR-22 could be restarted every 24 hours for ten consecutive days. And this is a major step towards testing the new rocket engine's reusability  in  Boeing's future unmanned space plane-- the Phantom Express. 

Boeing's first test flights of the Phantom Express are currently scheduled for 2021. But the final test of the reusable space plane will entail launching the Phantom Express ten times in just  ten days while deploying payloads between  3000 to 5000 lbs (1.36 tonnes to 2.27 tonnes) to LEO with an expendable upper stage.

Launching the Phantom Express with a single rocket engine, the AR-22 will be designed to be utilized up to ten times before requiring refurbishment.  And each AR-22 engine will have an ultimate lifetime of 55 missions before before being completely replaced by a brand new AR-22 engine.  Boeing estimates the cost to launch a the Phantom Express to be less than $5 million. And Boeing plans to  commercialize the  Phantom Express, offering the space plane to both US government and commercial customers.

Artist rendition of Phantom Express at launch pad with side mounted cargo rocket (Credit: Boeing Aerospace)
Just seven AR-22 engines would have to be produced every year  in order for the Phantom Express to be  continuously launched on a daily basis.

If the  Phantom Express were used to transport a valuable commodity such as water to LEO then 13 to 22 tonnes of water could be launched into orbit in ten days for less than $50 million, more than 40 tonnes of water in a month, and  for less than $500 million. Optimally, the most advanced version of NASA's Space Launch System is eventually supposed to be able to deploy up to  130 tonnes of payload to orbit for about $500 million per launch. But for less than $500 million, 100 hundred launches of the Phantom Express could deliver between 130 tonnes to 220 tonnes of water to LEO.

Total mass of a commodity that can be deployed to LEO via daily launch of a single Phantom Express space plane:

Daily - 1.36  to 2.27 tonnes

Monthly - 40.8  to 68.1 tonnes

Yearly - 496.4  to 828.6 tonnes 

Water, of course, is an indispensable commodity for human survival on Earth. And water would be even more valuable for human commerce and survival in extraterrestrial environments. Aboard the ISS, water is used for drinking, washing, food preparation, and for the production of air through electrolysis. Water can also be used for growing fruits and vegetables, aquaculture, animal husbandry. Water can also be used for  shielding astronauts from the extremely deleterious heavy nuclei component of cosmic radiation while also mitigating the effects of cosmic radiation in general and ions from major solar events (solar storms).



But electrolysis used to produce oxygen for air also produces hydrogen. And electricity can also be used to liquefy both oxygen and hydrogen for use as a propellant for reusable extraterrestrial vehicles. While the current  SLS could deploy up to 90 tonnes to LEO, it can only transport about  25 tonnes of cargo on a trans lunar injection trajectory.  But with the assistance of LEO orbiting propellant producing water depots, a reusable extraterrestrial vehicle  such as the ULA's future LOX/LH2 fueled  Integrated Vehicle Fluids (IVF) ACES-68 could transport more than 50 tonnes of payload on a trans lunar trajectory. And a notional  IVF  modified SLS Exploration Upper Stage (R-EUS) could be used to  transport  more than 100 tonnes of payload on a trans lunar  trajectory.
Notional propellant producing water depot with twin solar array (Credit: Lockheed Martin)

The propellant producing water depots could be simply derived from the propellant tanks of extraterrestrial vehicles with the edition of radiation panels, water storage, electrolysis plants for splitting the water into hydrogen and oxygen , and cryocoolers to liquefy the gaseous hydrogen and oxygen. Such depots could also be equipped with IVF thrusters for station keeping and with rocket engines to enable the depot to self deploy practically anywhere within cis-lunar space and even into orbit around Mars, Venus, Jupiter, and the asteroids in the asteroid belt.

A depot derived from the ACES upper stage could store up to 68 tonnes of LOX/LH2 propellant while an EUS derived depot could store up to 128 tonnes of LOX/LH2 propellant. Reusable upper stage rockets that  use liquid methane instead of hydrogen as fuel, could utilize the excess amount of oxygen (22%) produced at depots that can't be used by the limited amount of  hydrogen produced.

The large solar arrays needed to provide power for propellant producing water depots in orbit could be deployed by commercial launch vehicles. The ULA's future Vulcan spacecraft with its 5.4 meter in diameter payload fairing could deploy a 300 MWe solar array to LEO with a single launch. Two such solar arrays docked to each other could provide up to 600 MWe of power within cis-lunar space.  Orbiting at  LEO, such depots should have access to ample sunlight for producing propellant 61% of the time. But at the Earth-Moon Langrange points, such as NRO, solar energy would be uninterrupted, allowing water depots to  produce liquid hydrogen and oxygen continuously as long as water is provided.

Reusable ACES or R-EUS derived orbital transfer vehicles could  transport water from LEO to other propellant producing water depots located at the Earth-Moon Lagrange points. But once water is manufactured and exported from the Moon's low gravity well, exports of water from LEO to the rest of cis-lunar space would probably be commercially non competitive. In fact, lunar sources of water might someday compete with water resources being exported to LEO from the surface of the Earth via the Phantom Express. 

Notional crewed Orion-ACES reusable shuttle approaching EUS derived propellant producing water depot @ NRO with 600 KWe solar array. The notional WPD-OTV-125 would be capable of storing up to 200 tonnes of water and up to  125 tonnes of LOX/LH2 water derived propellant. 
Traveling to the moon using a propellant producing water depot architecture could be much easier and safer since vehicles returning from deep space would simply return to Earth orbit instead of plunging directly through the Earth's atmosphere to the Earth's surface. Commercial Crew launched vehicles could simply launch astronauts or paying tourist to LEO to dock with a commercial space station. A reusable ACES upper stage perhaps joined with an Orion capsule with no Service Module would refuel at a nearby propellant depot and then dock with the space station to pick up the passengers from Earth. The Orion-ACES would then travel for about five days to an orbiting commercial outpost located at NRO (Near Rectilinear Lunar Orbit). A XEUS vehicle would refuel at a nearby propellant depot and then dock at the deep space habitat to pick up the passengers. Less than  12 hours would be required to transport the passengers to the lunar surface and the XEUS would still have enough propellant to return the crew back to the NRO habitat for the return trip to LEO and then back to the Earth's surface.

The daily deployment of water to LEO by the Phantom Express could allow other launch vehicles to focus their efforts on deploying passengers and large and heavy habitats, crewed interplanetary spacecraft, and other large structures to LEO where they could easily be transported to other areas of cis-lunar space and beyond by reusable orbital transfer vehicles such as the future ACES or IVF modified EUS. 

Links and References

SSME returns as AR-22 for rapid reuse demonstration, fired ten times in ten days

Engineers Test Fire Reusable Rocket

First Phantom Express spaceplane engine completed

Cis-Lunar Gateways and the Advantages of Near Rectilinear Orbits

Efficient Utilization of the Space Launch System in the Age of Propellant Depots



Monday, August 6, 2018

Thor and the Thorium Solution for Plutonium from Commercial Nuclear Reactors


"Thor's battle with the giants" painting by Mårten Eskil Winge (1872)
by Marcel F. Williams

Because of the political inability to deal with the long term disposal of spent fuel from commercial nuclear reactors in the US by the federal government, some states in the US have banned the building of new  commercial nuclear power plants.

California state law, for instance, has banned the construction of new commercial nuclear power plants until the US Federal government establishes a long-term policy on the disposal of spent fuel (nuclear waste). And with current plans to close its last nuclear power plant (Diablo Canyon) by the year 2025, California will eventually have no  nuclear facilities providing carbon neutral electricity to its nearly 40 million residents.

While the US has principally focused on finding a permanent site for the spent fuel from its commercial nuclear facilities, some nations, such as France,  have focused on recycling the plutonium component of spent fuel while storing away the fissile and fertile uranium for perhaps future use in commercial nuclear reactors-- plus the residual radioactive material that cannot be recycled

While France mixes plutonium with uranium 238 (MOX) to partially recycle nuclear waste in its current light water reactors, this process produces even more plutonium. But  a Swedish company (Thor Energy) has come up with an alternative solution. They propose mixing the plutonium from spent fuel with fertile thorium instead of fertile uranium 238. The utilization of such fuel in conventional light water reactors would allow for the plutonium to be incinerated while producing electricity while producing fissile uranium 233 that could be eventually extracted and used to enrich the spent fuel containing fissile uranium 235 and fertile uranium 238 stored away. This would allow most spent fuel produced from nuclear reactors to be recycled to produce even more carbon neutral energy.
North American Thorium Deposits

  
Countries with the Largest Thorium Reserves (tonnes)

India ......................    846,000
Turkey...................     744,000
Brazil ....................     606,000
Australia ...............    521,000
USA ......................     434,000
Egypt....................      380,000
Norway.................      320,000
Venezuela.............      300,000
Canada.................      172,000
Russia..................       155,000
South Africa........      148,000
China...................      100,000
Greenland..............     86,000
Finland..................      60,000
Sweden..................      50,000
Kazakhstan............     50,000


Thor Energy envisions using a mix of 90% thorium and 10% plutonium in conventional light water reactors.  Thorium Mox could also be used in future underwater light water nuclear reactors such as France's FlexBlue system.  Remotely sited underwater reactors could be used to produce carbon neutral synfuels (methanol, gasoline, jet fuel, diesel fuel, etc.) which could be shipped to coastal towns and cities around the world for  transportation and local heat and electricity production. 

But a Swedish company, Thor Energy,  has come up with a solution that utilizes  fertile thorium enriched with fissile plutonium, creating energy while incinerating plutonium and producing fissile uranium 233.

Links and References

Thor Energy

California's last nuclear power plant to close by 2025

Spent Fuel and the Thorium Solution 

Blue submarine: The Flexblue offshore nuclear reactor

 The Case for Remotely Sited Underwater Nuclear Reactors

Siting Ocean Nuclear Power Plants in Remote US Territorial Waters for the Carbon Neutral Production of Synfuels and Industrial Chemicals

Will Russia and China Dominate Ocean Nuclear Technology?

The Future of Ocean Nuclear Synfuel Production

Floating Nuclear Power Plants, Floating Power Barges, and Marine Methanol

Nuclear Navy's Synfuel from Seawater Program: An interview with Kathy Lewis of the U.S. Naval Research Laboratory


Monday, July 30, 2018

Simplified Extraterrestrial Cargo and Crew Landing Vehicles for the SLS


Notional crewed ELV-3 on the surface of the Moon
by Marcel F. Williams

During NASA's Constellation program, the American space agency chose Boeing's Altair concept as the landing vehicle design to  return American astronauts to the surface of the Moon. As a two staged (descent and ascent) crew landing vehicle and as a single stage cargo landing vehicle,  the Altair was supposed to be housed in the large payload fairing of the Ares V super heavy lift rocket. But in 2010, the Constellation program was  canceled by the Obama administration, a decision that became law in April of 2011. And this ended the development of  Ares V and Altair lunar landing vehicle. 
Notional Altair crew landing vehicle (Credit: NASA)
Notional Altair cargo landing vehicle (Credit: NASA)

A year later, Congress began funding a new heavy lift program, the Space Launch System (SLS),   while continuing to fund the development of the  Orion component of the Constellation program. While there has been no significant Congressional funding for a lunar landing vehicle, a large variety of a vehicle concepts have been proposed to return American astronauts and cargo back to the lunar surface by several space companies.  
2.4 meter super lightweight cryotank (Credit: Boeing Aerospace)
Here, I propose another  reusable extraterrestrial cargo and crew landing vehicle (the ELV-3) concept that would be much simpler than Boeing's Altair vehicle. The ELV-3 would be launched by the SLS and utilized  to  deploy very large and heavy cargo or crews to the lunar surface. And with the addition of a HIAD or an ADEPT deceleration shield, the ELV-3 could also deploy largo cargoes and crew to the surface of Mars.
Notional ELV-3 lunar lander display retractable panel
X-ray view of three tank configuration for ELV-3
View of ELV-3 radiator and side thrusters
Top x-ray view of ELV-3 and its three tank configuration
Technologically, the notional ELV-3 spacecraft proposed here would be a substantially simpler vehicle than Boeing's canceled Altair spacecraft. Instead of the Altair's descent vehicle's four liquid oxygen tanks accompanied by four liquid hydrogen tanks, the ELV-3 would have just two 2.4 meter in diameter hydrogen tanks plus one 2.4 meter in diameter liquid oxygen tank, all linear aligned within an octagonal shaped cruciform.

 The problems associated with eight feedlines, differential tank pull due to unuasable propellant, increased tank heating resulting from the numerous tank penetrations, problems with pressure control during burns and long coastal phases caused by the large number of tanks are significantly reduced by reducing the cryotank numbers from eight down to just three. Utilizing just three tanks also reduces the overall mass of the tank weight.

Problems associated with the RL-10 exhaust plume just a few meters above the lunar surface during landings could be alleviated by using side thrusters positioned well above the surface. Additionally, the IVF (Integrated Vehicle Fluids) ullage gas fueled thrusters could also be automatically extended outwards away from the side panels (more than 8.4 meters in diameter) for exceptionally large payloads that extend beyond the diameter of the octagonal panels.

While the deck of the  ELV-3 would be approximately two meters higher than the Altair, the ELV-3 would have the advantage of a substantial amount of empty space on each side of the linear aligned propellant tanks. Twin retractable wall panels on each side could  accommodate a rectangular cargo area at least 7.2 meters high by 2.2 meters by 2.8 meters.

ELV-3 - Cargo Lander

One 2.4 meter in diameter LOX tank

Two 2.4 meter in diameter LH2 tanks

IVF thrusters utilize ullage gasses 

Dry mass: 8 tonnes

Propellant mass: 31 tonnes

Maximum cargo mass to lunar surface from NRO (Near Rectilinear Orbit):  30 tonnes

Maximum cargo mass to lunar surface from LLO: 39 tonnes

Twin mobile lunar cranes stored within the ELV-3 side cargo areas with additional cargo located at the top central area

The large dimensions of the side cargo areas would also be able to accommodate twin mobile lunar cranes with telescopic booms extending well above the the top deck.  Each electric powered crane would be equipped with a cable hook for unloading large payloads and with cable clamshells for digging up and redepositing lunar regolith. With each mobile crane already weighing more than 12 tonnes, the deposition of lunar regolith (weighing approximately 1.5 tonnes per square meter) into the automatically expanded regolith bins of the other vehicle could increase each crane's counter weight by more than 18 tonnes. This would allow each mobile crane to be able to easily offload payloads on top of the ELV-3 weighing nearly 30 tonnes. If devices are deployed to the lunar surface to magnetically extract iron and other metallic dust  from the top ten centimeters of lunar regolith then the deposition of this much heavy material into the regolith bins could easily increase the counter weights of the mobile cranes by more than 100 tonnes.
Panel deployment of twin mobile lunar cranes  
The deployment of such mobile lunar cranes could, of course, be used to unload and transport payloads from a variety of other lunar landing cargo space craft.

Notional electric powered mobile lunar crane
The clamshell crane could also be used to deposit regolith within the surrounding walls of lunar habitats providing the large multilevel pressurized habitats with appropriate shielding against cosmic radiation (completely shielding the habitats from the heavy nuclei component). Such regolith shielding could provide the habitat with protection from micrometeorites and from the extreme thermal fluctuations from the lunar environment.

Mobile lunar crane using its telescopic boom to lift a 20 tonne SLS propellant tank derived lunar habitat from the top of an ELV-3 cargo lander. The 20 tonne payload, of course, would weigh only one sixth as much on the lunar surface.
The cargo version of the ELV-3 could also be utilized to transport large and heavy payloads to the martian surface if HIAD or ADEPT deceleration shields are utilized along with mobile cranes with lifting capabilities not too dissimilar to vehicles deployed to the lunar surface. 


ELV-3 - Crew lander

Dry mass with mass with passengers, cargo,  and radiation shielding: 16 tonnes

Maximum additional cargo to and from the lunar surface if able to refuel on the lunar surface: 14 tonnes

Notional ELV-3 crew landing vehicle
As a crew vehicle, the ELV-3 would use three pressurized modules derived from Boeing's 2.4 meter in diameter tank technology. The centrally positioned module (passenger module) would be the heaviest since it would be internally heavily shielded to protect astronauts from the exceptionally deleterious heavy nuclei component of cosmic rays. This would add at least four tonnes of extra shielding weight to the passenger module relative to the similar sized command module and airlock on opposite sides of the passenger module. The passenger module  would also serve as a storm shelter in case of a major solar event when the ELV-3 is moving through cis-lunar space.

Because of its weight and limited fuel (up to 31 tonnes of LOX/LH2 propellant), two  vehicles would be required for round trip sortie missions between NRO and the lunar surface. One ELV-3 would be used to transport the other ELV-3 and its crew to low lunar orbit while the crewed ELV-3 would land on the lunar surface and then return to lunar orbit after its mission where the orbiting ELV-3 would transport both vehicles  back to NRO.  So spacecraft such as the ULA's XEUS (up to 68 tonnes of LOX/LH2 propellant) and Lockheed Martin's MADV (80 tonnes of LOX/LH2 propellant) would be much more capable than the ELV-3 as a crew launch vehicle for sortie missions since  only one vehicle is required for sortie missions originating from NRO.

However,  once propellant producing depots are deployed to the lunar surface, only one ELV-3 vehicle would be required to transport crews between the Earth-Moon Lagrange points and the lunar surface and back. Additionally, the crewed versions of the ELV-3 would have a major advantage by being able to transport both astronauts plus more than 14 tonnes of additional payload to and from the lunar surface  when fully fueled.
After a side panel is deployed, astronauts ride an electric powered scissor lift down towards the lunar surface
If propellant producing water depots are deployed at LEO and NRO, the ELV-3 could also be used transport crews between LEO and NRO. This would provide NASA and private commercial space transportation companies with an alternate means from LEO to the Lagrange points.  

Utilizing its side cargo areas,  an unmanned ELV-3 could also be used  to deploy a multitude of mobile robots to the surfaces the Moon, the moons of Mars (Deimos and Phobos), to the moons of Jupiter (Io, Ganymede, Europa, and Callisto), and even to the surfaces of some of the the largest asteroids in the asteroid belt (Ceres, Vesta, Pallas, etc.). 


Links and References

Robust Lunar Exploration Using an Efficient Lunar Lander Derived from Existing Upper Stages
 
Altair spacecraft

Tanks for a Great Idea

Game Changing Propellant Tank

2.4 meter composite cryogenic tank at Boeing Developmental Center

Pioneering and Commercial Advantages of Permanent Outpost on the Moon and Mars

Lockheed Martin's Reusable Extraterrestrial Landing Vehicle Concept for the Moon and Mars




Tuesday, June 5, 2018

Cis-Lunar Gateways and the Advantages of Near Rectilinear Orbits


Computer illustration of Near Rectilinear Orbits between EML1 and EML2 (Credit: NASA).

NASA appears to have settled on a Near Rectilinear L2 Halo Orbit (NRO) for its future Deep Space Habitat (DSH).  NROs are a subset of of L1 or L2 halo  orbits. NRO's have  large amplitudes over either the north or south lunar poles with shorter periods that pass closely to the opposite pole. Station keeping at an NRO would require a delta-v of only 5 m/s per year. With an impulsive departure from LEO at about 3.124 km/s, a crewed spacecraft would reach an L2  NRO in about 5.33 days. Orbital capture would require a delta-v of 0.829 km/s. 

An  EML1 location for a DSH  would only require a delta-v of  3.77 km/s and four days of travel time. But 2 days of travel time would be required for a journey from EML1 to Low Lunar Orbit (LLO). An NRO location, however, would only require 12 hours of travel time to LLO. So the surface of the Moon could be accessed from a NRO located Deep Space Hab in just 12 hours.


Possible Cis-Lunar Locations for a DSH (Deep Space Habitat)

EML1(Earth-Moon Lagrange Point One):


Travel time to and  from LEO:  ~4 days (3.77 km/s)

Station keeping: < 10 m/s per year

Travel time to and from LLO: ~ 2 days (0.750 km/s)


EML2  (Earth Moon Lagrange Point Two):


Travel time to and  from LEO:~ 8 days from LEO (3.43 km/s)

Station keeping < 10 m/s per year

Travel time to and from LLO:~ 3 days to LLO (0.8 km/s)


DRO (Distant Retrograde Orbit):
 

Travel time to and  from LEO: ~ 6 days

Station keeping: 0 m/s per year

Travel time to and from LLO: ~ 4 days  (0.83 km/s)


NRO: (Near Rectilinear Halo Orbit):


Travel time to and  from LEO:~5 days from LEO (3.95 km/s)

Station keeping: 5 m/s per year
 
Travel time to and from LLO:~ 12 hours to LLO (0.730 km/s)




Significantly shorter flight times from LEO to NRO could be achieved with higher delta-v levels that could easily be achieved by future reusable LOX/LH2 fueled spacecraft such as the ULA's XEUS and Lockheed Martin's MADV which could be used for round trip journeys to the lunar surface from a NRO and for transporting crews between LEO and NRO.


Links and References 
 

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