Monday, January 27, 2014

The Future of Ocean Nuclear Synfuel Production

Artist’s rendition of the Russian floating nuclear power plant “Akademik Lomonosov” (Credit: SevMashZevod)
by Marcel F. Williams

Land based commercial nuclear power  is the safest form of electricity production ever created. No one died as the result of radiation exposure at the Fukushima nuclear facilities in Japan-- despite three meltdowns-- thanks to the inherent safety of the containment structures. But even if you include the mortality rate of the Chernobyl nuclear accident which didn't have a containment structure, the mortality rate for commercial nuclear energy is 90 deaths per trillion kWhr compared to:

Wind, 150 deaths per trillion kWhr

 Rooftop solar,   440 deaths per trillion kWhr,

Hydroelectric, 1400 deaths per trillion kWhr

Natural gas,  4000 deaths per trillion kWhr

Coal, a whopping 170,000 deaths per trillion kWhr.

However, these statistical facts have not alleviated the unreasonable fear that many have of commercial nuclear energy-- nor people's paradoxical phobia of radiation in general. This seems ironic since Americans exist in a society where radioactive materials are commonly used in nearby facilities such as hospitals and clinics. Americans are also  frequently exposed to much higher levels of cosmic radiation when they're flying in the upper atmosphere on airliners. Astronauts endure levels of radiation while in orbit much higher than what would be allowed for nuclear workers on Earth on a daily basis.  Americans also don't seem to have any fear about joining the US Navy to serve on nuclear powered aircraft carriers and submarines. And families don't seem to have any fears about  greeting their sons and daughters and husbands and wives when they depart from nuclear vessels on their return to shore.  

Still, there are many who have an almost innate fear of commercial nuclear power. And this unreasonable fear by some American's could seriously imperil the environment and the  quality of life for future generations.

Humans are currently living within an atmosphere that is alien to our species and even to our 2.6 million year old genus, Homo. Our use of fossil fuels has now pumped so much carbon dioxide into the air  that CO2 now comprises more than  400 parts per million of our atmosphere. These are levels of CO2 that have not existed on the Earth since the Pliocene, a warm epoch that spanned 5.3 million years ago until 2.6 million years ago when sea levels may have been as much as 40 meters higher than they are today. And as the polar  ice caps continue to melt and sea levels continue to rise, there are no signs that our civilization is currently stopping the increase of  greenhouse gasses into our atmosphere through the burning of fossil fuels. 

Yet the United States and most other industrial countries could easily stop the increase in CO2 levels into the atmosphere within the next 20 to 30 years if we simply built a lot more nuclear power plants for both  electricity and synthetic fuel production. There's already enough room at the more than 60   nuclear sites in the US to increase nuclear generation at each site to at least 8 GWe. That would be more than enough electricity to replace the electricity from fossil fuels in the US.

But what about transportation fuels for automobiles, trucks, ships, plains, and heavy ground vehicles?

Fortunately, a new generation of small nuclear reactors is about to emerge in the United States and in  the rest of the world. These small nuclear reactors offer the promise of an even more enhanced level of commercial nuclear safety while also substantially lowering the cost of manufacturing and deploying nuclear power through centralized manufacturing,  mass production, and transport by barge or rail to a nuclear power facility.

The first of this new generation of small nuclear reactors is being deployed by the Russians-- not the United States. But its not a land based reactor. It is a floating nuclear reactor. And floating nuclear reactors could be the key towards finally galvanizing broad acceptance of nuclear energy for all. 

Russia  intends to  mass produce floating 70 MWe nuclear power plants at shipbuilding facilities. These will then be towed   to coastal waters near industrial centers, towns and cities for the production of electricity and desalinated water.

The US once had the intention of deploying an offshore nuclear power facility as a way to avoid the increasing difficulties of licensing land based reactors. Four larger reactors were to be deployed by Westinghouse just 16 kilometers north of Atlantic City at the mouth of Great Bay. But licensing these off-shore reactors proved to be just as publicly difficult as land based reactors. And the project was eventually canceled.

But what if we deployed some floating nuclear reactors far out to sea-- far away from the  coastal environments of any town or city and the licensing headaches associated with coastal deployment.  Instead, these Ocean Nuclear power plants would be deployed hundreds or even over a thousand kilometers away from continental coastlines for the production of carbon neutral synthetic fuels. These clean synthetic fuels could then be shipped to any fuel port in the world for the production of electricity or for utilization as transportation fuel for automobiles, trucks, plains, and ships.
The conversion of seawater into methanol through nuclear electricity

The US Navy has recently revealed that they have developed a technology that can produce carbon neutral synthetic fuels from seawater by simply using a carbon neutral source of electricity. This technology takes advantage of the fact that the concentration of bound and dissolved carbon dioxide in seawater is  approximately 140 times greater than in the atmosphere. At the same time, the hydrogen contained in the seawater could be extracted through electrolysis and synthesized with CO2 to manufacture a variety of hydrocarbon fuels.

While the US Navy is focusing its attention on using nuclear or renewable OTEC technologies for manufacturing jet fuel at sea, the Navy's new technology  could be easily utilized to manufacture other carbon neutral fuels such as methanol, dimethyl ether, diesel fuel, and even gasoline.

The production of methanol at sea could allow floating nuclear power plants to ship this carbon neutral fuel  to practically any coastal port on Earth-- for  electricity production and for ground transportation fuel. Methanol tankers already exist and  come in a wide variety of sizes for transporting large quantities of methanol.

Methanol is relatively non-corrosive fuel that  remains at a liquid state at room temperature and atmospheric pressure. Methanol requires no specialized containment and can be handled the same way as other oil based liquid fuels.  Since methanol is easily biodegradable  in marine waters, an accidental  tanker spill would be much less damaging to the marine environment and to coastal beaches  than an oil or gasoline spill. 

Japanese Methanol Tanker (Credit: SHIN KURUSHIMA DOCKYARD CO)

For electricity production, methanol can be easily used in  modified natural gas turbines. Tests have shown that,  compared to natural gas,  methanol produces a  higher electrical power output due to the higher mass flow, and significantly reduces NOx and while also producing  no SO2 emissions at all. The clean burning characteristic of methanol are also expected to reduce maintenance costs for a converted natural gas turbine. So using carbon neutral methanol for electric power production would not only reduce global warming but would also mean cleaner air in general. Methanol can be easily pumped via pipelines to modified turbine power plants located in inland regions for distribution to electric power  all over the mainland United States. Of course, on islands such as Hawaii, methanol could finally end the islands'  dependence on high priced oil for electricity.

Methanol can also be used in fuel cell power plants which an be used for back up electricity for buildings or for homes. And methanol fuel cells are currently used to power portable electronic devices.

Methanol electric power plant at Point Lisas, Trinidad (Credit: Mendenhall Technical Services)
Methanol can also be used to power seagoing vessels. And some ocean vessels have already been designed to use methanol in order to reduce pollution from vessels using diesel fuel.

Methanol can also be easily converted into dimethyl ether (DME) through dehydration over a catalyst.  Only moderate modifications are required to enable a diesel fuel engine to burn dimethyl ether. And dimethyl ether is a much cleaner fuel than  diesel fuel for trucks and other heavy ground vehicles.

The further dehydration of dimethyl ether can convert it into high octane gasoline. This carbon neutral gasoline can be either mixed with existing fossil fuel derived sources of gasoline or can be used to completely replace gasoline derived from fossil fuels.

Conversion of Methanol into Dimethyl Ether and Gasoline for ground transportation vehicles
So nuclear power plants floating far out to sea in the worlds oceans could potentially supply carbon neutral fuels for both electricity and transportation fuel for the entire planet. Such Ocean Nuclear  facilities could be easily designed to withstand the havoc of hurricanes, cyclones, and other tropical storms while also being inherently immune to earthquakes and tsunamis. But storm related production disruptions could easily be avoided by locating such facilities in regions where the frequency of tropical storm formation is very infrequent.

The colored areas  are regions where cyclones and hurricanes are most frequently created in the world's oceans (Credit: National Oceanic and Atmospheric Administration)
But Ocean Nuclear complexes could still be located at latitudes where winter snow could be avoided in order to attract more employees to work at the remote ocean facilities. Semi-permanently docked cruise ships could be purchased by a large Ocean  Nuplex to provide housing, recreation, restaurants, shopping malls, small hospitals and schools for its nuclear power plant and synfuel operators and engineers and their families.

Since small nuclear reactors will be designed to produce 300 MWe of electricity or less, that means that thousands of small nuclear reactors would have to be mass produced and deployed to sea in order to replace America's  transportation fuel needs alone. If nuclear manufactured methanol were also required to  replace all of America's  peak load electricity production  then several hundred more small reactors would also have to be manufactured. Of course, if the US wanted to export carbon neutral fuels to other countries then thousands more small nuclear power plants would have to be built and deployed to sea.

Centrally manufacturing dozens or even  hundreds of small nuclear reactors in the US every year would dramatically reduce the capital cost  nuclear reactors and, therefore, the cost of synthetic fuels being produce from these Ocean Nuclear facilities.  This would mean millions of high wage manufacturing jobs being created on the American continent for the production of floating nuclear power plants that most Americans would never see. Such nuclear ocean synfuel production facilities could be clustered in an area less than 100 square kilometers (a 10 kilometers by 10 kilometers) while producing 25 to 50 GWe of power for synfuel production.

Large remote Ocean Nuplexes  could also be used to produce jet fuel, and even ammonia for fertilizer (synthesis of atmospheric nitrogen combined with hydrogen extracted from seawater through electrolysis).

US Navy nuclear aircraft carriers could  stop by such Ocean Nuclear complexes to refuel their vessels with jet fuel and also for some R&R for the crew at one or more of the Nuplex cruise ships which could feature a large variety of entertainment and shops  which could add more revenue for the Ocean Nuclear Complex.

Security for Ocean Nuclear facilities could also be provided by the US Coast Guard, easily affordable by a large nuclear complex without any tax payer expense. They would also, of course, have their own security forces.   

There might also be logistical advantages for locating floating  uranium extraction platforms within a few dozen or a few hundred kilometers of an  Ocean Nuclear Complex. There's more than 4 billion tonnes of natural uranium in seawater, enough to power and fuel all of human civilization for over 3000 years. And if the spent fuel is eventually recycled in next generation breeder reactors then uranium could supply civilization with power for more than 300,000 years. However, since the  uranium content of the oceans will be resupplied with its current uranium content in less than 150,000 years, marine uranium could, in theory, supply human energy needs for as long as humans remain on Earth. Of course, this doesn't even include terrestrial thorium supplies and potential extraterrestrial uranium and thorium supplies within the solar system in the future.

Floating airports located perhaps 10 to 100  kilometers  away from an  Ocean Nuplex could take advantage of their proximity to synthetic jet fuel,  cheap electricity, and desalinated water supplies.  Underwater electric power cables that stretch more than 500  kilometers away from their power source are already in existence.

Floating space launch facilities in the future could also take advantage of Ocean Nuclear complexes located near the Earth's equatorial regions to take full delta-v advantage  of the Earth's rotation. Launch facilities located less than 80 kilometers away from an Ocean Nuplex could utilize the abundant hydrogen and oxygen produced at the floating nuclear facility-- for cryogenic rocket fuel

Ironically, Ocean Nuclear facilities might also attract new communities of people living on floating artificial islands. Such floating island communities might be located just 100 to 500 kilometers away from an Ocean Nuclear complex, taking advantage of the cheap nuclear electricity and high paying jobs-- along with the warm climate and spectacular ocean views! But even at just 100 kilometers away from the floating Nuplex, from the balcony of your floating home, you'd still be at least 70  kilometers away from from being able to see the nuclear power facility over the curve of the beautiful blue horizon!

Marcel F. Williams

Links and References

Tuesday, January 14, 2014

Utilizing Space Shuttle Main Engines (SSME) for Early SLS Cargo Launches and Commercial Crew Destinations

Some of the SSME (RS-25D) in storage at the Kennedy Space Center (Credit NASA).
by Marcel F. Williams

NASA's future Space Launch System (SLS) won't be fully operational until it can utilize the new expendable RS-25E engines which probably won't be ready until the year 2021. However, NASA has 16 Space Shuttle Main Engines (SSME: RS-25D), previously used by the Space Shuttle stored away for use by the SLS. Since the SLS will utilize four engines per flight, the SSME could launch up to four SLS missions before the arrival of the expendable RS-25E engines. But the safety of astronauts launched on the SLS may depend on utilizing these engines on unmanned test missions.

Simulated Video of Delta IV Heavy Launch of the CM of the MPCV
In 2014, NASA will use the ULA's Delta-IV heavy to test launch the Command Module (CM) of the future Multipurpose Crew Vehicle (MPCV),  placing it in low Earth orbit for reentry back on Earth. The  Service Module (SM) of the MPCV, however, will still be under development by the European Space Agency and won't be available to launch with the CM until   2017

MPCV (Credit: NASA)

The SLS heavy lift vehicle will make its maiden launch in 2017 along with the complete version of the MPCV . This unmanned flight could be as simple as sending the MPCV to TLI (TransLunar Injection) or on more complex journeys to the Earth-Moon Lagrange points or to some other points of interest within cis-lunar space. 

After 2017, NASA has no SLS missions scheduled until 2021 when the first crewed missions of the SLS/MPCV are scheduled to begin and the new RS-25E engines are scheduled to be utilized. It would also mean that astronauts would be launched on top of the SLS after just one unmanned test flight! But  NASA would still have 12 SSME that could be utilized for cargo missions before 2021 that could further insure the safety of the SLS for manned spaceflight.

 During the Apollo era, there were two unmanned test flights of the Saturn V heavy lift vehicle before NASA finally took a chance and launched three American  astronauts into orbit around the Moon in December of  1968. The first unmanned test flight of the Saturn V in November of 1967-- was a complete success. However, there were some  problems with the second and third stages of the Saturn V during  the second unmanned test  in April of 1968

Of course, serious problems with the Apollo Command Module occurred  during a launch rehearsal test on  January 27th, 1967 which cost the lives of three American astronauts:  Virgil I. "Gus" Grissom (a former Mercury astronaut),  Edward H. White (the first American to walk in space), and  Roger B. Chaffee-- an astronaut who never got a chance to fly into space.

So as far as safety is concerned, I believe it would be prudent for NASA to launch the SLS more than just one time-- unmanned-- before actually placing living human beings on top of the new heavy lift vehicle. 
But that doesn't mean that such early SLS flights can't also be put to good use. Below is a proposal for two additional SLS flights before the first manned flight of the SLS/MPCV in 2021:

CST-100 Commercial Crew Vehicle docked with the Olympus BA-2100 space station (Credit: Boeing)
Interior of the Olympus BA-2100 space station (Credit Bigelow Aerospace)

I propose that in 2019,  NASA should launch the Bigelow Aerospace company's Olympus BA-2100 space station to LEO for-- private commercial utilization. While Bigelow Aerospace would pay for the development of the BA-2100, under this scenario,  NASA would pay for the launch of the habitat in exchange for up to 60 days of annual exclusive use of the facility-- with the exception of Bigelow Aerospace maintenance personal aboard the space station. 

This would give Bigelow Aerospace the advantage of having a huge space station in orbit for exclusive  fee based Commercial Crew and foreign spacecraft  visitations at least 10 months out of the year.   Bigelow could still pay  private launch companys to deploy its smaller microgravity facilities (BA-300) nearby. This would allow small specialized microgravity labs to function without human interference while the human engineers and scientist took shelter at the larger Olympus space station until the experiments are completed and the results can be retrieved from the smaller facilities. Human access to the Olympus space station will, of course, depend on the availability of operational Commercial Crew spacecraft which should be available to NASA well before 2019.

Skylab 2 (Credit: Brand Griffin)
Hypergravity Centrifuge (Credit: NASA)
 I also propose that in 2020, an orbital habitat derived from the SLS hydrogen  fuel tank, similar to the Skylab 2 proposal,  also  be deployed by the SLS to  LEO. Such a habitat could be equipped with a six meter in diameter internal hyper gravity centrifuge-- easily accommodated within the 8.4 meter interior diameter of the space station. This will enable NASA to see if one to two hours of hypergravity per day  can  significantly mitigate some of the deleterious effects of microgravity on the human body. The new NASA space station will also be supplied with enough water shielding to protect astronauts from major solar events while also  reducing their long term exposure to cosmic radiation. Again, NASA will need to utilize Commercial Crew services in order to access the SLS deployed NASA space station at LEO. In the 2020's, a similar SLS derived habitat will be placed at one of the Earth-Moon Lagrange points and could someday be used to house astronauts on interplanetary journeys.

So before the Space Launch System is fully operational in the early 2020s, the old Space Shuttle Main Engines could allow the SLS to deploy two enormous space stations: one privately owned  and one owned by NASA. Both stations could serve as places of refuge if one of the stations had to be abandoned in an emergency. And they could both serve  as  way stations for future reusable Orbital Transfer Vehicles headed towards the Earth-Moon Lagrange points or to Lunar orbit. A new generation of space stations would allow NASA to finally move beyond the ISS while focusing its efforts and finances on beyond LEO missions to the Moon and beyond.

Adding two additional unmanned SLS launches should help to enhance the launch vehicles safety and reliability before manned missions begin in 2021.  And, under this scenario, four SSME would still be available in case the  RS-25E engines are still not ready for manned SLS missions by 2021. 

Marcel F. Williams

Links and References:

Thursday, January 9, 2014

Lori Garver Questioned Astronauts about NASA's Next Destination?

In a fascinating oped in the Huffington Post, former astronaut, Clayton Anderson, reports that  Lori Garver had a private meeting with the Astronaut Corp. when she was still the  Associate Administrator for NASA Spaceflight-- and asked the astronauts what NASA's next destination should be:

"While I was still an astronaut, and an astronaut veteran at that, then Associate Administrator for spaceflight Lori Garver came to speak to the Astronaut Corps. A private meeting, just Ms. Garver and an attentive group of type A personalities, I would venture to guess there were about 40-45 of us "space fliers" seated in the room. A bit of a "rah, rah" meeting, touting NASA's work in the world of commercial spaceflight (and I think commercial spaceflight is a good thing, but that's another op-ed!), she asked us all a significant question.

After some perfunctory remarks, she asked us to raise our hands if "we thought that Mars should be our next destination?" Three astronauts raised their hands.

Next, she offered the question again, but this time replacing the Red Planet with the option of an asteroid as our next destination. No one... that's right, no one, raised a hand.

When she finally asked us about our near-neighbor the moon, every astronaut, save the three that voted for Mars, raised their hands.

 I found this interesting. The majority of the astronaut corps, the people that actually do the space flying, agreed with me --that the moon should be our next destination.
Clayton Anderson.

You can read the rest of Clayton Anderson's oped at the Huffington Post at:

Marcel F. Williams

More  Blogs about Lori Garver: 

Where Do We Go From Here?

Report: NASA Astronauts Oppose Obama Asteroid Mission

How Lori Garver misled about '50 year old' Space Launch System Technology

Huntsville-designed Space Launch System should be killed, former NASA No. 2 Lori Garver says

Wednesday, January 1, 2014

An SLS Launched Cargo and Crew Lunar Transportation System Utilizing an ETLV Architecture

SLS launched ETLV-2 at EML1 liquid hydrogen and oxygen  fuel depot (ETLV derived) while the MPCV waits to dock with the now fully fueled lunar landing vehicle
by Marcel F. Williams

Before the end of the decade, the heavy lift capability that America once had during the Apollo  era-- will return in the form of the SLS.  Some, however, have argued that because of the former Space Shuttle's ability to deploy a 94 tonne aerospace plane plus up to 25 tonnes of useful cargo to LEO that , technically,  the Shuttle was also a  heavy lift vehicle. But even the earliest versions of the Space Launch System will be  far more capable than the Space Shuttle in their ability to lift huge payloads into orbit. Unmanned versions of the  SLS should be capable of deploying at least  70 tonnes of payload to LEO.  And with an SLS derived upperstage, as much as 105 tonnes of cargo could be lifted to orbit. Even when deploying the 22 tonne MPCV (Multipurpose Crew Vehicle), the SLS should still be capable of simultaneously  lifting an additional 45 to 80 tonnes of cargo to orbital space.

SLS crew launch and cargo launch vehicles; with an upper stage, the SLS would be capable of deploying nearly 39 tonnes of payload to Trans-Lunar Injection

Still there are those who argue that the SLS could  be deficient in its ability to deploy large crew landers and heavy cargo to the lunar surface-- relative to the now cancelled Ares V configurations. However, any deficiency in the lifting capability of the SLS could be easily compensated for by  deploying-- fuel depots-- at the Earth-Moon Lagrange Points, or in low Lunar orbit, or both. This might suggest to some NASA critics that the space agency would have to spend substantially more of its limited funds in order to finance still another expensive component for  its beyond LEO architecture-- in addition to funding the development of  lunar crew and cargo vehicles. 

 Delta-V budgets & Destination Travel Times

LEO to TLI - 3.2 km/s dv

LEO to LLO (~2 days) - 4.5 km/s dv

LEO to LLO (~4 days) - 3.97 km/s dv

LEO to EML1 (~2 days) - 4.41 km/s dv

LEO to EML1 (~4 days) - 3.77 km/s dv

EML1 to or from LLO (~2 days) - 0.75 km/s dv

EML1 to or from  LLO (~3 days) - 0.64 km/s dv

LLO to or from the Lunar surface - 1.87 to 2.1 km/s dv

LEO: Low Earth Orbit; TLI: Trans-Lunar Injection; LLO: Low Lunar Orbit; 
EML1: Earth Moon Lagrange Point 1

(Credit John Connolly: NASA-JSC - 2012)

However, if the next lunar landing vehicle developed for NASA is a-- single stage reusable spacecraft-- then a Lagrange point  fuel depot and a lunar surface fuel  depot  could both be derived from the reusable lunar lander.  Such a reusable single staged lunar vehicle-- would already be inherently designed to refuel and store cryogenic fuels with zero boil-off. So deriving the fuel depot directly from the tanks utilized for the lunar landing vehicle could significantly reduce development cost. Additionally,  the landing vehicle's reusability should also substantially  reduce its annual recurring cost for transporting humans to the lunar surface. 

In an earlier post, I described a reusable single staged lunar landing vehicle concept that  I called the ETLV-2 (Extraterrestrial Landing Vehicle 2). The vehicle would be designed to take  full advantage of a large  8.4 meter to 10 meter SLS payload fairing.  

The ETLV-2 would utilize four CECE engines but just two common bulkhead tanks; each tank would be capable of storing up to 14 tonnes of liquid oxygen and hydrogen fuel. The tanks would utilize a ULA type of Integrated Vehicle Fluid (IVF) technology plus NASA's breakthrough  cryocooler technology to eliminate fuel boil-off and the waste of ullage gases. Such technologies could substantially reduce tank insulation and the overall weight of the space vehicle. 
Basic components of the ETLV-2 lunar landing vehicle

The four RL-10 derived CECE (Common Extensible Cryogenic Engine) engines should enhance vehicle safety with engine out capability and reusability with up to 50 restarts capability. 

Vehicle development cost are further reduced in this concept by deriving the crew habitat module and airlocks from the light weight cryotanks. The pressurized crew hab should be tall enough to accommodate a crew
of at least seven individuals, pressure suits, and small cargo on three floor levels. Such a large crew capacity would  make the ETLV-2 potentially compatible with Commercial Crew launched vehicles since such privately operated vehicles should be capable of transporting as many as seven individuals  to Earth orbit per flight. The ETLV-2 would, of course,  also be capable accommodating the maximum crew of six aboard the MPCV.    

The twin airlocks of the ETLV-2 would be utilized for giving humans access to the lunar surface through one airlock  while the second airlock will allow small mobile robots and mobile vehicles access to the lunar surface on the opposite side of the vehicle.  As an unmanned vehicle, the ETLV-2 could potentially be utilized for robotic sample retrieval missions to the lunar surface and possibly to the surfaces of the moons of Mars. In both cases, the regolith samples retrieved from deployed mobile robots would be returned to the Earth-Moon Lagrange points where a MPCV would dock with the unmanned ETLV-2 to pick up the samples for their journey to the Earth.  

Fully fueled, the ETLV-2 should still weigh less than 38 tonnes and could, therefore, be deployed to TLI by the SLS upper stage

ETLV-2 lunar landing vehicle: front, corners, & top views

While the ETLV-2 lunar lander would use only two long fuel tanks for its crewed missions to the lunar surface, the EML1 fuel depot concept proposed here would utilize five of the  ETLV-2 tanks within a taller cruciform. The EML1 fuel depot could potentially store more than 60 tonnes of cryogenic fuels.  The L1 fuel depot envisioned here would also be capable of perpetually storing up to 100 tonnes of water and be capable of converting the water into liquid hydrogen and oxygen through solar powered electroysis and cryocooler technology. The space fuel depot would also be capable of self deploying itself practically anywhere within cis-lunar space and even into orbit around Mars and Venus.

A single SLS launch would initially be required to deploy the fuel depot  to EML1 with as much as 20 tonnes of cryogenic fuel. Since the ETLV-2 crew lander  would only require a few extra tonnes of additional fuel when it arrived at L1, 20 tonnes should be enough fuel for perhaps three round trips from L1 to the lunar surface-- if new mostly fueled ETLV-2 vehicle arrives at L1 each time from Earth.   However,  MPCV launches by the SLS to EML1 should be capable of carrying several tonnes of additional cargo. So several tonnes of water cargo could be stored aboard the SLS upper stage along with the MPCV. So any extraction of fuel from the EML1 depot for crewed ETLV-2 lunar missions could be replaced  by water deliveries tagging along with the MPCV flights
 An  ETLV derived cargo lander (C-ETLV-4) would be used to deliver up to ten tonnes of payload to the lunar surface. The C-ETLV-4 would be primarily used for deploying the heavy machinery, ground vehicles, and crew habitats necessary to establish a permanently peopled  water and fuel producing and exporting Lunar outpost-- similar to that envisioned by Dr. Spudis and Lovoie in their most recent papers. 

C-ETLV-4 Cargo Lunar Lander: front, top, and interior position of fuel tanks
Since I envision NASA having at least two operational SLS launch pads by the early 2020s-- a two launch scenario-- would be utilized for early manned missions to the lunar surface. Such a launch infrastructure could also allow at least four heavy lift launches per year for both cargo and crew missions. 

NASA's first manned lunar mission utilizing the SLS  could send the ETLV-2 to TLI (Trans-Lunar Injection) where the remotely controlled unmanned crew lander will separate from the SLS upper stage and utilize some of its fuel to reach EML1. The ETLV-2 will then dock with the previously SLS deployed  EML1 fuel depot in order to add the additional required fuel for its round trip journey to the lunar surface and back to L1.

A second SLS launch, probably a few days later,  would send the MPCV plus a few tonnes of water  to EML1. The MPCV will dock with the fully fueled ETLV-2 and the crew (up to 6 people) will transfer to the lunar lander for their  journey to the Lunar surface and then, eventually, back to L1 after their lunar mission is over. The EML1 fuel depot will dock with the water tank, stored at the top of  the SLS upper stage, and pump the water into the fuel depot water compartment where it will eventually be converted into liquid hydrogen and oxygen.

On their return trip to EML1, the crew will transfer back to the MPCV for their return to Earth.  Under this scenario,
the deployed ETLV-2 would remain at L1  until the EML1 fuel depot is finally being supplied with water from the lunar surface for the manufacture of extraterrestrial fuel. This will allow a small fleet of reusable lunar landers to be deployed at EML1 by the SLS over just a few years for future use for manned lunar missions. Once an ETLV-2 vehicle is reactivated, it will refuel at L1 and then travel-- unmanned back to the lunar surface--  to ensure that the reusable vehicle is fully functional for human use again.  The ETLV-2's CECE engines could be utilized for at least ten round trips before they would be required to be replaced-- or the landing vehicle retired.

I should note that the two launch scenario can also be utilized-- even if their is only one launch pad for the SLS (delaying the next launch from the pad for a few months)-- since the ETLV-2 would be equiped with cryocoolers capable of re-liquifying ullage gasses from is fuel tanks, providing zero boil-off of fuel for several months or even several years. However, limiting the SLS  to just two launches per year would substantially slow down  progress towards establishing  manned outpost on the lunar surface and eventually on the surface of Mars. But there's really no logical reason to limit heavy lift launches to just two a year since NASA was able to launch as many as-- four heavy lift vehicles per year-- during the Apollo era and as many as nine Space Shuttle missions per year during the peak of the Shuttle era

Once the fleet of ETLV-2 landing vehicles are utilizing lunar fuel resources for their operation and lunar water is being exported to the EML1 fuel depot from ETLV derived lunar tankers, NASA should then be able to incorporate the use of Commercial Crew vehicles as a cheaper component for sending astronauts to the Lunar surface. Reusable, ETLV-2 derived reusable Orbital Transfer Vehicles (OTVs) equipped  with delta-v reducing aerobrakers should allow NASA to travel between LEO and EML1 a lot more cheaply. NASA astronauts and possibly even space tourist could then travel to the Moon by first taking  a Commercial Crew vehicle to LEO where they would dock with an ETLV-2 derived OTV that utilizes lunar fuel stored at EML1 and possibly also at LEO. Once at EML1, the ETLV-2 would take the passengers down to the lunar surface.

So under this proposed scenario, the SLS and the MPCV could be used to set up a reusable  transportation infrastructure that could eventually give passengers aboard private Commercial Crew launch vehicles affordable and convenient access to the surface of the Moon-- just a few years after the SLS/MPCV/ETLV program begins.  

Further details about the ETLV components that will give Commercial Crew passengers access to the lunar surface will be discussed  in more detail  in future post.

 Marcel F. Williams
© 2013 MuOmega Enterprises

Blog Archive


Popular Posts