Showing posts with label hydrogen. Show all posts
Showing posts with label hydrogen. Show all posts

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





Tuesday, October 24, 2017

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

Notional MADV on the surface of Mars (Credit: Lockheed Martin)
by Marcel F. Williams

 At the 68th International Astronautical Congress, held in Australia last September, Lockheed Martin  unveiled a remarkable new extraterrestrial spacecraft concept.  The single staged space vehicle would be capable of landing either  unmanned or crewed on the surfaces of the Moon or Mars. The MADV (Mars Ascent/Descent Vehicle) would be a propellant depot dependent spacecraft fueled with liquid oxygen and liquid hydrogen. And the MADV would be capable of transporting four member crews to the surfaces of the Moon or Mars. 

MADV (Mars Ascent/Descent Vehicle)

Propellant: 80 tonnes of LOX/LH2 

Inert weight: 30 tonnes 

Engines: 6 RL-10 engines

Maximum delta v capability:  6.0 km/s

Crew: Up to four astronauts

Notional MADV on the polar surface of the Moon (Credit: Lockheed Martin)
After landing on the lunar or martian surface, crews would utilize an electric powered lift located on the vehicle's leeward side to access the surface from the pressurized crew cabin.  Located between its six RL-10 engines, near the bottom of the vehicle, a retractable equipment lift would be lowered to deploy mobile vehicles and other equipment for use on the surface.

However, the MADV's  high delta-v capability (6 km/s)  could also allow the spacecraft to be used as a crew transport  within cis-lunar space. Utilizing pre-deployed propellant manufacturing water depots at LEO and EML1, the MADV could easily transport crews between LEO to EML1-- even with the addition of a  crew hab (10 to 20 tonnes in mass)  with  protective shielding against heavy ions. 

Notional MADV on top of an SLS Block IB (Credit: Lockheed Martin)
 MADV Capabilities

1. Unmanned lunar lander for deploying mobile robotic vehicles and unmanned sample returns

2. A crewed lunar lander capable of traveling to the lunar surface and back to the propellant depots and Deep Space Habitats located at EML1-- on a single tank of fuel

3. Unmanned Mars lander for deploying mobile robotic vehicles for unmanned sample returns from the martian surface.

4. A crewed Mars lander capable of traveling from low Mars orbit to the martian surface and back to low Mars orbit-- on a single tank of fuel.

5. If fueled from a depot in high Mars orbit, it could land directly on the martian surface for Mars outpost operations.

6. If refueled from a depot near an outpost on the martian surface, the MADV could transport its crew all the way to a permanent habitat stationed in high Mars orbit.

7. A crewed orbital transfer vehicle capable of transporting astronauts from propellant depots located at  LEO to propellant depots located at any of the Earth-Moon Lagrange points or in  low lunar orbit.

8. The SLS Block IB could be utilized to transport the MADV to LEO with enough fuel to deploy  itself anywhere within cis-lunar space (EML1, EML2, EML4, EML5, Low Lunar Orbit).

9. An SLS launched  MADV could also arrive at LEO with  enough propellant to transport itself all the way to propellant manufacturing water depots located in high Mars orbit.

Notional landing and take-off of the MADV to and from the surface of Mars (Credit: Lockheed Martin)

Maximum Delta-V Budget for the MADV (6.0 km/s)

Cis-Lunar Space Delta-V

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

LEO to EML1 (~4 days) - 3.77 km/s 

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

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

LEO to  LLO (~2 days) - 4.5 km/s

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

LLO to or from the Lunar surface - 1.87 to 2.2 km/s

Mars Delta-V

LMO (500 km circular orbit) EDL to Martian surface - 1.27 km/s

Mars surface to LMO (500 km circular orbit)  - 4.2 km/s

HMO to or from  LMO - 1.4 km/s

HMO to Martian surface via 500 km circular orbit - 2.67 km/s

Mars surface to HMO - 5.6 km/s

LEO to HMO - 5.2 km/s

LEO- Low Earth Orbit, EML1 - Earth-Moon Lagrange Point 1, LLO- Low Lunar Orbit, HMO - High Mars Orbit, LMO - Low Mars Orbit, EDL - Entry, Descent, and Landing


The development and deployment of the MADV still wouldn't negate the need for large unmanned cargo landing vehicles for the Moon and Mars. Such landing craft would be needed to deploy large and heavy habitats, vehicles and other large structures  to the surfaces of the Moon and Mars and, eventually, to other worlds within the solar system.

But  a single stage extraterrestrial landing vehicle such as the MADV should be faster and cheaper to develop than previous two stage crew concepts for the Moon and Mars. So Lockheed Martin's  MADV could be a game changer as a reusable extraterrestrial vehicle capable of using a propellant depot architecture within cis-lunar space and beyond.  And with its high delta-v capability, the MADV could also be the landing vehicle of choice for conveniently transporting humans to the surfaces of the Moon, Mars, Mercury, Callisto, and possibly even Saturn's moon,  Titan, during the rest of the  21st century.   

Links and References

Mars Base Updates and New Concepts

Lockheed Martin Mars Lander Ship Concept (Video)

 Lockheed Martin Adds Lander to Mars Base Concept

On Orbit Refueling: Supporting a Robust Cislunar Space Economy

Mars Base Camp (Video)

Tuesday, January 27, 2015

Utilizing Lunar Water Resources for Human Voyages to Mars

At EML4, an OTV-400 interplanetary booster  undocks with a fuel depot (WPD-OTV-400) before proceeding to dock with the  Odyssey interplanetary spacecraft. 

by Marcel F. Williams

Long interplanetary journeys to  Mars, or to the orbit of Venus, or even to some of  the NEO asteroids could take several months or even years before their human occupants finally return to the relative safety of the Earth's surface. Such interplanetary voyages will require a substantial tonnage of water  for drinking, washing, the preparation of food,  the manufacturing of oxygen for air,  the production of  liquid oxygen and hydrogen for propellant, and for appropriately shielding humans inside of  habitat modules from the dangers of cosmic radiation and major solar events.

NASA delta-v estimates for  achieving Mars Transfer Orbits from LEO during the 2030s range above 3.8 km/s to just below 5 km/s-- just to reach the vicinity of Mars. Additionally,  a LEO departure for Mars would require launching the huge amounts of water and propellant for the voyage out of the Earth's enormous gravity well. This would require a delta-v ranging from 9.3 to 10 km/s.

However, if  crewed interplanetary vehicles are launched from an Earth-Moon Lagrange point, the delta-v requirements to achieve a Mars Transfer Orbit would be substantially lower. The delta-v requirements for departing cis-lunar space from one of the Earth-Moon Lagrange points could be less than 2 km/s-- especially if an Earth flyby or an Earth and Moon flyby (even better) are taken advantage of during the initial trajectory burns.

Providing water and propellant for  crewed interplanetary mission from the lunar surface to an Earth-Moon Lagrange point would also have a substantially lower delta-v requirement.  A  delta-v of less than  2.6 km/s would only be required to supply water and propellant to an interplanetary gateway at an  Earth-Moon Lagrange point. Contrast that with the  enormous  9.3  to 10 km/s delta-v that is need to  supply propellant and water to an interplanetary vehicle located at LEO.  The lunar supply of water and propellant to an interplanetary spacecraft at an  Earth-Moon Lagrange point would also have the additional economic advantage of being able to use single stage reusable vehicles. 

Earth-Moon Lagrange Points, the optimal gateways to interplanetary space within cis-lunar space.
So  launching  crewed interplanetary space craft to Mars from one of the Earth-Moon Lagrange points (L1, L2, L4, or L5) has a substantial delta-v advantage over launching crewed interplanetary spacecraft from LEO--  if such spacecraft are supplied with fuel and water from the surface of the Moon. 

During the 2030s, entering High Mars Orbit during a Conjunction Class Mission (330 to 560 day stays) would require an additional delta-v of 0.9 to 1.9 km/s, while entering High Mars Orbit during  Opposition Class Missions (60 day stay)  would require an additional delta-v trajectory burn ranging from  0.9 to 3.8 km/s. The additional delta-v requirements for reaching High Mars Orbit adds further support for minimizing the initial delta-v requirements when departing from cis-lunar space. So, again, supply fuel and water from the Moon from an Earth-Moon Lagrange point gateway would appear to be the optimal way to begin crewed interplanetary journeys. 

But how much water is there on the lunar surface? And how technologically difficult would it be  to extract large quantities of water from the lunar regolith?

A spectral analysis of the ejecta plume from the impact of  a Centaur upper stage  into the  Cabeus crater at the lunar south pole was conducted in 2009.  The analysis indicated that the lunar regolith in the shadowed crater contained water ice with concentrations ranging from 2.7% to 8.5% by mass. This suggest that  in some of the permanently shadowed craters at the southern pole, the lunar regolith there may contain as much as  27 to 85 kilograms of ice per tonne

The dark purple and blue areas represent neutron emissions from the Moon's polar regions that indicate  hydrogen-rich regions on the lunar surface covered by desiccated regolith (Credit: NASA) .  
In the Moon's northern polar region, the Mini-RF on board the Chandrayaan-1 orbiting probe strongly suggest that 40  craters in the northern polar region my contain as much as 600 million tonnes of water-ice. So there is clearly no shortage of  water resources on the lunar surface.

In order to provide enough water for human activities at a lunar outpost, a cis-lunar transportation system, and to supply propellant and mass shielding for five Conjunction or Opposition Class missions to Mars during the 2030s: 2030, 2033, 2035, 2037, and 2039, at least 500 to 1000 tonnes of water is going to have to be annually manufactured on the lunar surface.

A lunar water and fuel manufacturing depot along side of mobile LOX and LH2 storage tanks and a mobile microwave water extraction robot (Water Bug).

NASA researchers have demonstrated that a simple one kilowatt microwave oven could extract as much as a tonne of water from the regolith at the lunar poles over a one year period. A single mobile robot with a 100 kw powered microwave oven, therefore, should be  able to annually extract 100 tonnes of water from the regolith from the shadowed areas at the lunar poles. Ten such mobile microwave units might be able to extract 1000 tonnes of water per year from lunar polar regolith resources.

Solar extraction of water from lunar regolith brought from permanently shaded lunar craters at the lunar poles. Transparent domes allows sunlight to heat a layer of lunar regolith from the top while solar heated metal tubes below filled with methanol heat the regolith from below. Water vapor is deposited within regolith insulated cold trap canisters.

However, a simpler method may only require sunlight to passively extract water from the lunar regolith. If one tone of regolith from the shadowed areas of the  lunar poles is composed of  approximately 5% water ice then mobile lunar excavators capable of digging up and depositing at least one tonne of regolith into a solar heater could produce at least 50 kg of water per day (18 tonnes of water per year). Just a few electric powered or fuel cell powered excavation robots on the lunar surface could, in theory,  deposit at least one ton of icy regolith to a solar heater per hour (more than 400 tonnes of water per year).
A reusable water tanker shuttle on a microwave sintered launch pad after being loaded with lunar water and lunar fuel for its flight to a water and propellant depot at one of the Earth-Moon Lagrange points.


The Odyssey interplanetary vehicles would be crewed spacecraft capable of transporting 12 astronauts to High Mars Orbit and back to cis-lunar space using solar photovoltaic powered propellant producing water depots supplied with water from the lunar surface. The Orbital Transfer Vehicle (OTV-400) and the IAGH (Interplanetary Artificial Gravity Habitats) would both be derived from the SLS fuel tank technology.

 The OTV-400 would use  a common bulk-head LOX/LH2 fuel tank derived from the SLS fuel tank technology. An IVL(Integrated Vehicle Fluids) type of technology would be used to utilize ullage gases for attitude control. Space Works has proposed a similar type of OTV using IVL technology that would store more than 450 tonnes of LOX/LH2 fuel. However, the OTV-400 would also use photovoltaic powered cryocoolers to  virtually eliminate any hydrogen and oxygen boil-off.
 
The twin habitat modules of the IAGH would rotate to produce a 0.5g simulated gravity for the six humans inside each module. The IAGH would also  be  appropriately water shielded to protect  its most radiation vulnerable occupants (25 year old female astronauts) from excessive exposure to  cosmic radiation and its  heavy nuclei component in a addition to major solar events-- for up to four years-- during solar minimum conditions. 50 cm of water shielding would be required to appropriately shield the light weight twin SLS fuel tank derived living areas: 118 tonnes of water shielding for each habitat module, 236 tonnes of shielding in total. 
A reusable Orbital Transfer Vehicle (OTV-400) for transporting crewed artificial gravity habitats to the orbits of Mars, Venus, or to the NEO asteroids. While some of the ullage gases are utilized for attitude control, most of the ullage gases are reliquified by photovoltaic powered cryocoolers to prevent fuel loss, a technology already developed by NASA.

Conjunction Class Missions would only require one reusable OTV-400  storing close to 400 tonnes of LOX/LH2 propellant. The higher delta-v Opposition Class Missions will require two reusable OTV-400 boosters. Entering orbit around Mars and reentering cis-lunar space will also require the IAGH  to dump the water shielding from its habitat modules in order to substantially reduce the Odyssey's mass just before the final trajectory burns to enter Mars orbit or to enter cis-lunar space.

Coupled with a large water storage tank and a photovoltaic powered electrolysis plant  and cryocoolers, the OTV-400 would function as a water storage and hydrogen and oxygen producing propeelant depot (WPD-OTV-400). Still equipped with its own rocket engines, it could self deploy itself practically anywhere within the inner part of the solar system  while still being able to manufacture LOX and LH2 anywhere where there is a source of water.

The WPD-OTV-400 water and propellant depot would have the ability to transport itself to Mars orbit from the Earth-Moon Lagrange points after producing enough fuel for its on flight and filling up with enough stored water originating from the Moon. However,  once water is being manufactured on Deimos and Phobos, using the same technologies employed on the lunar surface, propellant from the lunar surface will no longer be required to replenish water and propellant supplies in orbit around Mars. 

Reusable Odyssey I interplanetary space craft with a crew of 12 at EML4 in a trajectory burn configuration for a Conjunction Class mission to High Mars Orbit  in the year 2033. 

After its initial trajectory burns on its way to Mars, the  OTV-400 boosters and the ETLV-2 vehicles (Extraterrestrial Landing Vehicles) would separate from the IAGH  and re-dock at its central axis.The Odyssey would, therefore, be reconfigured  to produce artificial gravity for its 12 person crew for their multi-month journey to Mars.   Liquid carbon dioxide rockets housed in each habitat module, would be used to rotate or to stop the rotation of the Odyssey. Cables will extend from the IAGH core more than 100 meters from the central axis of the vehicle. A series of light weight cylindrical metal or ceramic shells woulds also expand outwards creating rotational arms that would act as levers to increase, decrease, or stop the rotation of the Odyssey. 

Reusable Odyssey II interplanetary space craft with a crew of 12 at EML4 in a trajectory burn configuration for a 1000 day Opposition Class mission to High Mars Orbit (60 day stay) to explore the martian moons Deimos and Phobos while also deploying  satellite constellations at Sun-Mars L1 and Sun-Mars L2 to provide global communications for future human missions to the surface of Mars.
After several months of travel through interplanetary space,  the Odyssey would reconfigure itself again to prepare for an Orbital Insertion trajectory burn and the water shielding within IAGH modules would be dumped into space.  But after a day or two in Mars orbit, the Odyssey will once again reconfigure itself to produce artificial gravity for its crew. The  water shielding for the habitats could be fully  restored within a few hours or a few days from a pre-deployed  WPD-OTV-400 already in high Mars orbit. Returning to Earth will also require the Odyssey to be refueled by the orbiting water and propellant depot in Mars orbit.

Once in high Mars orbit, each fully fueled  crewed ETLV-2 vehicle would have enough fuel to travel to one of the Martian moons for a few days of exploration and sample retrieval  and back to the Odyssey. And if they wanted to travel to the martian moons a second time then they could refuel at the orbiting Mars depot (WPD-OTV-5).

A slowly rotating Odyssey II in an interplanetary configuration to provide a simulated gravity of  0.5 g  for six crew members in each of the  IAGH habitat modules. 
Since the Odyssey is intended for reuse (ten times with its RL-10 engines) for future interplanetary missions, a trajectory burn will be required to return to the Earth-Moon Lagrange points after the trajectory burn for Trans-Earth Injection from Mars orbit. Again, this will require the Odyssey to completely dump its water shielding before the burn. Once the crew is back within cis-lunar space, they will only be a few hours away from protective shelters on the lunar surface or just a few days away from the Earth's surface.

After the 12 person crew completes their 60 day mission in High Mars Orbit, the Odyssey II converts from it's artificial gravity configuration to a trajectory burn configuration for its Trans-Earth Injection burn to begin its journey back to cis-lunar space.

 Because the major Odyssey components are reusable, the recurring cost for the interplanetary vehicle should be substantially lower that other interplanetary vehicle concepts that utilized expendable interplanetary boosters. The Odyssey's RL-10 or RL-10-like rocket engines could also be periodically replaced after perhaps ten round trips between cis-lunar space and Mars orbit which could further reduce their recurring cost.

The human safety advantages of using  lunar water resources for an SLS derived reusable artificial gravity producing  interplanetary spacecraft   deployed at one of the Earth-Moon Lagrange points should also be substantial:


1. The significantly reduced delta-v requirements at an Earth-Moon Lagrange point for fueling and mass shielding a crewed interplanetary vehicle should alleviate any pressure to significantly reduce the appropriate mass shielding of habitat modules against the dangers of cosmic radiation and major solar events. 50 cm of water shielding should also eliminate the possibility of space career ending radiation exposure during a single interplanetary mission for the most vulnerable occupants to radiation.

2. The rotating interplanetary artificial gravity habitats (IAGH) could significantly or totally eliminate long periods of exposure to the  deleterious physical effects of a microgravity environment

3. Having twin AGH habitats allows astronauts the enhanced safety of being able to seek refuge in the opposite habitat in case there is a serious life safety malfunction at the other habitat.

4. The more comfortable accommodations of the spacious SLS derived artificial gravity habitats could significantly reduce the psychological stress experienced by the drew  during several months or years of interplanetary travel.

5. The dangers and the complexity of direct, high-energy aerobraking into the atmospheres of Mars or during a return to directly to Earth would be avoided by limiting the Odyssey's flight path to travel only between the Earth-Moon Lagrange points and High Mars Orbit.

6. With at least one partially fueled  ETLV-2 (Extraterrestrial Landing Vehicle) connected to the Odyssey, any major malfunction of the OTV-400 during an orbital capture trajectory could allow astronauts to safely enter Mars orbit or cis-lunar space via the ETLV-2 vehicle or vehicles.  Even though this would mean the loss of the Odyssey spacecraft, the crew could still safely enter Mars orbit or cis-lunar space via the ETLV-2. However, Entering Mars orbit aboard an ETLV-2, without the Odyssey IAGH would require that an appropriately mass shielded space station already be pre-deployed in Mars orbit.



References and Links


Considerations for Designing a Human Mission to the Martian Moons (NASA)

A Study of CPS Stages for Missions beyond LEO (Space Works)

Mission and Implementation of an Affordable Lunar Return (Spudis & Lavoie) 

 Using the resources of the Moon to create a permanent, cislunar space faring system (Spudis & Lavoie)

Evolving to a Depot-Based Space Transportation Architecture (ULA)

 SLS Fuel Tank Derived Artificial Gravity Habitats, Interplanetary Vehicles, & Fuel Depots

 Utilizing the SLS to Build a Cis-Lunar Highway

Cosmic Radiation and the New Frontier





Friday, April 17, 2009

The Nuclear Synfuel Economy

by Marcel F. Williams

Currently, commercial nuclear energy in the US and in the rest of the world is solely utilized for the production of electricity. The 104 commercial nuclear reactors in the US provides nearly 20% of the electricity produced in the United States. But electricity only constitutes about 40% of America's total energy consumption. So even if nuclear power totally supplanted all other electric power generating systems in the US today, nuclear power would still only provide 40% of America's total energy needs. However, the rise of electric vehicles (EVs) and plug-in hybrid vehicles (PHEV) over the next few decades could greatly expand the use of electricity in ground transportation vehicles that normally use gasoline.

Petroleum consumption in the US also constitutes approximately 40% of the energy use in the US. America uses nearly 21 million barrels a day of petroleum with nearly 15 million barrels a day utilized for transportation fuel (gasoline, diesel fuel, jet fuel). But the US currently produces less than 9 million barrels a day of petroleum (the US is still the third largest producers of oil on Earth) and imports more than 12 million barrels a day of petroleum. So the US only produces 43% of its own oil while currently importing more than 57% of the petroleum required for domestic transportation and industrial chemical use.

Chevy Volt PHEV

Gasoline constitutes approximately 61% of the transportation fuel utilized in America. Studies have shown that the use of electricity for PHEVs could potentially displace up to 6.5 million barrels of oil per day, more than half of the imported oil coming to America (31% of total petroleum consumption in the US). Nuclear electricity, therefore, could potentially supplant nearly 31% of US petroleum requirements.

But what about the other 69% of US petroleum needs?

Up to 388 million dry tons a year of urban biowaste, 325 million tons of forest refuse, and 597 million tons of agricultural waste could be exploited from our cities, forest, and current agricultural acreage to produce carbon-neutral biofuels (gasoline, methanol, diesel fuel, and jet fuel), an equivalent of approximately 4 million barrels of oil per day (19% of total US daily petroleum consumption). So the addition of carbon neutral biowaste from urban and rural areas could further reduce US petroleum needs to only 50% of current levels.

Fuel cell methanol vehicle

Methanol fuel cells utilized to power automobiles could be twice as efficient as current automobile engines and could potentially reduce petroleum demand by an additional 3.2 million barrels a day equivalent of oil. That would further reduce daily petroleum needs to just 35% of current levels. Since the US produces 38% of its own petroleum, this would-- in theory-- make the US energy independent from foreign oil. But as the third largest producer of oil on Earth, the US would still remain a major greenhouse gas polluter. Electricity from batteries from plug-in hybrids would provide equivalent cost of only 75 cents per gallon. Fuel cells could also cut the energy cost of methanol in half. So even the highest priced synthetics fuels in the future would probably cost consumers less than they are paying now-- if they drove PHEV-fuel cell automobiles.

The synthesis of biomass into biofuels waste 80% of its carbon content in the form of carbon dioxide. But if hydrogen were added to the mix, biowaste could potentially supply up to 20 million barrels of oil equivalent of biofuels annually. And nuclear power plants could be used to produce hydrogen through the electrolysis of water. However, the extraction of CO2 from the atmosphere may be a more efficient mechanism for supply CO2 for nuclear electrolysis facilities in the long run. So nuclear power in combination with biowaste fuels would not only make the US totally independent of petroleum fuels but would also make the US a major exporter of carbon neutral synfuels.

In a pure nuclear synfuel economy, approximately 1170 nuclear reactors (1100 MWe of capacity each) dedicated for synfuel production, would be required to supply all of the carbon neutral industrial chemical and liquid fuel needs in the US today. However, in a hydrogen-biofuel economy that utilizes urban and rural biowaste in combination with highly efficient automobiles that utilize PHEV and fuel cell technologies, only 410 nuclear reactors dedicated to synfuel production would be required for America to become totally independent from foreign and domestic petroleum fuels, ending greenhouse gas pollution from the petroleum economy in the US-- forever.




References and Links

1. Michael Kintner-Meyer, Kevin Schneider, Robert Pratt IMPACTS ASSESSMENT OF PLUG-IN HYBRID VEHICLES ON ELECTRIC UTILITIES AND REGIONAL U.S. POWER GRIDS PART 1: TECHNICAL ANALYSIS
Pacific Northwest National Laboratory November, 2007


2. G. Olah, A. Goeppert, and G. Prakash, (2006) Beyond Oil and Gas: The Methanol Economy, Wiley-VCH Verlang, Weinheim, Germany

3. Robert D. Perlack, Lynn L. Wright, Anthony F. Turhollow, Bryce J. Stokes,Donald C. Erbach, Robin L. Graham, (2005)BIOMASS AS FEEDSTOCK FOR A BIOENERGY AND BIOPRODUCTS INDUSTRY: THE TECHNICAL FEASIBILITY OF A BILLION-TON ANNUAL SUPPLY Oak Ridge National Laboratory A Joint Study Sponsored by the U.S. Department of Energy and the U.S. Department of Agriculture

4. Agrawal, R, Singh, N R, Ribeiro, F H , Delgass, W N , (Mar 2007) Sustainable fuel for the transportation sector. Proceedings of the National Academy of Sciences of the United States of America, 104 (12), p.4828-4833,


5. Green Freedom: A concept for producing carbon-neutral synthetic fuels and chemicals, Los Alamos Labs, November 2007 F.J. Martin and WL Kubic,

6. Gasoline from Air and Water

7. The Plug-in Hybrid Revolution


© Marcel F. Williams
New Papyrus

Monday, November 24, 2008

Gasoline from Air and Water

by Marcel F. Williams

Fossil fuels are predominantly responsible for putting excess carbon dioxide and methane into the Earth's atmosphere, greenhouse gases that are melting our polar ice caps, raising global sea levels, and causing more extreme climate conditions around the world. The coal and natural gas power industry has looked looked towards future technologies for the on site capture of flu gas in order to recover and sequester carbon dioxide. However, there is no cost effective technology for capturing the CO2 from the mobile producers of carbon dioxide: automobiles, trucks, aircraft, and sea craft.

But there are new technologies that are rapidly being developed that may eventually divorce carbon dioxide polluting sources of energy from the need for on site capture and sequestration of carbon dioxide. These devices are sometimes referred to as mechanical trees. But what they do is to simply extract and recover carbon dioxide from the atmosphere. And these future technologies appear to be far more efficient at extracting CO2 from the air than the plant life on our planet.

Some argue that these carbon dioxide from air extracting technologies could be the saviors of the fossil fuel industry. Ironically, such future technologies could also eventually lead to the complete extinction of fossil use on this planet if the CO2 taken from the atmosphere is used in combination with hydrogen from water to produce hydrocarbon fuels such as: gasoline, methanol, diesel fuel, jet fuel, and dimethyl ether.

Hydrogen

Because the combustion of hydrogen produces only energy and water, hydrogen via the electrolysis of water through hydroelectric, nuclear, wind, and solar has often been proposed as a replacement for hydrocarbon transportation fuels. Liquid hydrogen fuel has been used in US space craft since the days of the Apollo Moon program. And liquid hydrogen has also been frequently proposed for future generation subsonic and hypersonic airliners and aircraft. Hydrogen fueled buses now transport commuters in many urban areas in the US. And hydrogen automobiles have been demonstrated by many automobile companies around the world .

However, hydrogen automobiles have a substantially shorter range than hydrocarbon fueled vehicles and are a lot less efficient than electric vehicles. Refueling hydrogen vehicles also takes much longer than refueling with gasoline, ethanol, or methanol. Because of the hydrogen embrittlement of metals like steel, hydrogen pipelines are more expensive to maintain than natural gas and oil pipelines. Aircraft, seacraft and ground vehicles, and the infrastructure associated with these vehicles, would also have to be completely replaced if we completely replaced our fuel economy with hydrogen.


Hydrocarbon fuels from CO2 and hydrogen

Alternatively, there are several demonstrated methods for synthesizing hydrocarbon fuels by utilizing carbon dioxide in combination with hydrogen which could allow a country to avoid any major overhaul in its transportation energy infrastructure.

Chemist have known how to produce methanol from hydrogen and carbon dioxide for more than 80 years:

CO2 + 3H2 → CH3OH (methanol) + H2O

Methanol is mostly used as a feedstock for making other chemicals. But methanol can be converted into dimethyl ether (DME), a fuel that can be effectively used in diesel engines equipped with new fuel injection systems. The fact that dimethyl ether produces no black smoke, soot, or sulfur dioxide is an clean advantage it has over diesel fuel.

Methanol can also be converted into high octane gasoline via the Mobil Oil methanol to gasoline (MTG) process. Back in the 1980's, the New Zealand government produced 600,000 tonnes of gasoline a year from methanol derived from natural gas using the MTG process.

Methane gas can also be synthesized from hydrogen and carbon dioxide:

CO2 + 4H2 → CH4 (methane) + 2H2O

And methane can also be converted into diesel and jet fuels via Fischer-Tropsch and hydrocracking processes.

Mechanical extraction of atmospheric CO2

Plants capture carbon dioxide from the atmosphere while utilizing sunlight to convert the CO2 into starch. During photosynthesis, trees, for instance, convert carbon dioxide and water into starche molecules and oxygen through a series of oxidation and reduction reactions:

6 CO2 + 6 H2O + sunlight ---> C6H12O6 + 6 O2

Some farm crops and trees can produce up to 20 metric tons per acre (4047 square meters) of biomass a year. One tonne of dried tree consist of 0.45 tonnes of carbon which would translate into the extraction of 1.65 tonnes of carbon dioxide annually extracted from the atmosphere. That's 33 tonnes of CO2 per acre extracted on an annual basis.

Even though the concentration of CO2 in the Earth's atmosphere is a meager 0.04 per cent, companies like GRT (Global Research Technologies) in Arizona and Canadian researchers at the University of Calgary have already built machines that can extract carbon dioxide from the atmosphere far more efficiently than any tree or any other source of biomass. GRT claims that its carbon dioxide air extraction system is a thousand times more efficient than a tree of equal size.


GRT CO2 absorbent material

The University of Calgary team has shown that they could capture CO2 directly from the atmosphere with less than 100 kilowatt-hours of electricity per tonne of carbon dioxide. Their carbon dioxide from air extraction tower was able to capture the equivalent of about 20 tonnes per year of CO2 on just one single square meter of air scrubbing material. Astonishingly, this suggest that even the most conservative estimates would allow these CO2 extracting machines to produce more than 80 thousand tonnes of carbon dioxide per acre annually.

University of Calgary carbon dioxide extraction machine


Because of the need for cheap electricity for hydrogen production, only nuclear and hydroelectric facilities would be currently viable for hydrocarbon fuel production utilizing carbon dioxide from air extraction technologies. Hydroelectric facilities currently produce electricity at 0 .85 cents per kwh while electricity from nuclear facilities currently cost 1.68 cents per kwh. Wind and solar thermal electricity, however, is much more expensive and ranges from over 4 cents per kwh to over 6 cents per kwh.

At the Los Alamos National Laboratory in Los Alamos, New Mexico, F. Jeffrey Martin and Williams L. Kubic, Jr. have developed the Green Freedom concept for using the cooling towers of nuclear reactors to extract carbon dioxide from the atmosphere for the production of gasoline and methanol. They argue that a 1 GWe power plant using their Green Freedom method could produce 18,000-bbl/day of gasoline or 5000 tonnes a day of methanol.

Carbon neutral hydrocarbon synfuel production at nuclear and hydroelectric facilities would not only allow such power facilities to produce transportation fuels and industrial chemicals, they would also allow them to pump methanol and oxygen up to 80 kilometers away to high efficiency power plants for the production of peak-load and back-up-load electricity and commercial waste heat. Nuclear power plants could therefore not only produce base-load electricity but could also supply methanol fuel to replace greenhouse polluting natural gas power plants which are used for daytime peak-load energy and back-up energy for wind and solar power plants.

In 2006, the US consumed nearly 21 million bbl/day of petroleum for transportation fuel and industrial chemical use. If we assumed that nuclear power plants replaced all of the petroleum used in the US in 2006, that would roughly require more than a thousand new 1Gwe nuclear reactors, over 1000 GWe of electrical capacity. Existing nuclear sites that already have nuclear reactors could probably add an additional 200 to 300 Gwe of capacity. However, if one large centralized nuplex (nuclear park) with about 30GWe of average electrical capacity were set up in every state in the union, then that could add an additional 1500 GWe of electrical capacity, more than enough to replace all of our petroleum needs today and probably our needs 30 years from now.

If the new Obama administration is going to invest substantial R&D money into new energy technologies, I would strongly suggest investing in the fast tracking of these carbon dioxide extraction from air technologies that could revolution synfuel production by helping to achieve US independence from the petroleum fuel economy while protecting the global environment from the dangers of global warming and climate change.

Links and References

1. Green Freedom: A concept for producing carbon-neutral synthetic fuels and chemicals, Los Alamos Labs, November 2007 F.J. Martin and WL Kubic,

2. GRT (Global Research Technologies, LLC)

3. Giant Carbon dioxide Vacuums

4. Snatching Carbon dioxide from the Atmosphere

5. CO2 capture from air

6. First Successful Demonstration of Carbon Dioxide Air Capture Technology Achieved:

7. First Successful Demonstration of Carbon Dioxide Air Capture Technology Achieved by Columbia University Scientist and Private Company, (2007) Earth Institute News Archive, 04/24/07

8. Carbon capture and storage:

9. Researchers Scramble to Create CO2-Busting Technologies:

10. CO2 capture from ambient air: a feasibility assessment:

11. Carbon Capture and Storage A False Solution

12. The Case for Carbon Dioxide Extraction from Air

13. Klaus S. Lackner, Patrick Grimes, Hans-J. Ziock, Capturing Carbon Dioxide From Air

14. K. Schultz, L. Bogart, G. Besenbruch, L. Brown, R. Buckingham, M. Campbell, B. Russ, and B. Wong HYDROGEN AND SYNTHETIC HYDROCARBON FUELS – A NATURAL SYNERGY General Atomics Poster

15. G. Olah, A. Goeppert, and G. Prakash, (2006) Beyond Oil and Gas: The Methanol Economy, Wiley-VCH Verlang, Weinheim, Germany


A New Papyrus Publication

Tuesday, January 1, 2008

NUCLEAR ENERGY









 

 

Ocean Nuclear Production of Green Methanol in Remote Japanese Territorial Waters- January 10, 2024

Uranium from Seawater as an Unlimited Source of Renewable Energy

 May 25, 2019 

Deploying Ocean Nuclear Energy Flotillas into International Waters for the Carbon Neutral Production of Synthetic Fuels, Industrial Chemicals, and Fertilizers

February 13, 2019

Thor and the Thorium Solution for Plutonium from Commercial Nuclear Reactors

August 6, 2018 

The Case for Remotely Sited Underwater Nuclear Reactors

March 26, 2018

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

 May 7, 2017

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

December 20, 2016

Will Russia and China Dominate Ocean Nuclear Technology?

February 9, 2016

The Nuclear Synfuel Economy
- April 17, 2009

The Nuplex Solution
- February 26, 2009

Synfuels and the Price of Oil
- February 19, 2009

The Relative Safety of the New Generation of Nuclear Reactors
- January 14, 2009

Energy Independence through Nuclear Re-Industrialization
- December 5, 2008

Gasoline from Air and Water
- November 24, 2008

Public Power & the Future of Nuclear Energy
- November 13, 2008

Natural Radiation
- October 20, 2008

The Cost of Non-Carbon Dioxide Polluting Technologies
- October 15, 2008

Fueling our Nuclear Future
- October 9, 2008

Federal support for non-carbon dioxide polluting energy technologies
- September 25, 2008

Short & Long Term Solutions for Nuclear Waste
- August 21, 2008

Gasoline from Nuclear and Renewable Energy
- August 8, 2008

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