Monday, December 21, 2020
Wednesday, December 16, 2020
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Wednesday, December 9, 2020
Monday, December 7, 2020
Saturday, December 5, 2020
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Monday, November 23, 2020
Saturday, November 21, 2020
Nuclear power plants are expensive for the same reason that rockets are expensive. They're mostly handcrafted structures. And relatively very few are built. Plus their principal components are usually not serially mass produced.
Currently, there are only 54 commercial nuclear reactors under construction world wide. Only two are under construction within the US. Eleven are under construction in China, seven in India, and Russia, South Korea, and the United Arab Emirates each have four under construction.
However, the US is scheduled to build nine new-- nuclear submarines.
The advent of small nuclear reactors that are being developed within the US and around the world should resolve the high capital cost problem of building nuclear reactors-- especially if most of the electricity produced from nuclear facilities is used to produce carbon neutral synthetic fuels through the electrolysis of water to produce hydrogen and the extraction of CO2 from the atmosphere to produce CO2.
Nuclear power produces about 20% of the electricity in the US and more than 50% of the carbon neutral electricity in the US. But existing nuclear sites in the US could easily produce at least 80% of the electricity if small reactors were gradually added to existing sites.
However, I believe that small remotely sited-- floating nuclear reactors-- used to produce renewable methanol (eMethanol) will finally end the world's dependence on fossil fuels. Methanol can be used to replace natural gas in natural gas electric power plants cheaply retrofitted to use methanol. Methanol can also be used in fuel cell automobiles and power plants. Methanol can also be converted into carbon neutral jet fuel and gasoline and dimethyl ether (a diesel fuel substitute). And methanol can power ships.
The seawater in the world's oceans contain about 4 billion tonnes of uranium which could be extracted and used to power human civilization on Earth pretty much as long as the Earth still has oceans. The source of this uranium is the ocean's natural interaction with the Earth's continental crust which contains more than 100 trillion tonnes of uranium.
There are currently more than 160 floating vessels powered by more than 200 nuclear reactors on the high seas. And such nuclear vessels have existed since the 1950s.
Friday, November 20, 2020
Tuesday, November 17, 2020
Sunday, November 15, 2020
Tuesday, November 10, 2020
|Notional RLV-4 Cargo vehicle in a distant Near Rectilinear Halo Orbit awaiting depot refueling before transporting a multilevel Lunar Regolith Habitat to an outpost at one of the lunar poles. |
by Marcel F. Williams
Privately financing the development of a reusable SLS deployed lunar landing vehicle should be a priority for the major Space Launch System partners: Boeing, Lockheed Martin, Aerojet Rocketdyne, and Northrup Grumman. A reusable single stage LOX/LH2 fueled vehicle (RLV-4 Crew) could be commercially successful as a crew lander by simply adding a-- pressurized habitat module-- already being developed by Lockheed Martin for the Blue Origin National Team.
Notional RLV-4 Crew vehicle with Lockheed Martin derived habitat module with crew deployment davit system.
By financing a single stage vehicle rather than a two stage vehicle, development cost could be substantially reduced by simply developing one vehicle instead of two. Further cost reductions could result from using engines and propellant tank technology that already exist. So a notional RLV-4 could use RL-10 derived CECE engines already developed by SLS partner Aerojet Rocketdyne and super lightweight composite propellant tanks already developed by Boeing.
I envision the RLV-4 Crew and RLV-4 Cargo vehicles going into operation by the year 2026. If we assume a development cost of $6 billion for the RLV-4 over the course of six years, then each SLS partner would be required to supply at least $250 million a year of funding for the development of the reusable RLV-4.
|Notional RLV-4 Cargo vehicle capable of being filled with up to 56 tonnes of LOX/LH2 propellant.|
Similar to the RLV-4 Crew vehicle, I envision the RLV-4 Cargo as being launched-- in pairs-- within the 9.1 meter in diameter dynamic envelope of a 10 meter in diameter SLS payload fairing. At its corners, the maximum diameter of the RLV-4 octagon would be 8.44 meters with a distance between each opposite 3.23 meter side of the octagon being approximately 7.8 meters. With the legs folded during launch, the RLV-4 could easily fit within the internal 9.1 meter in diameter dynamic envelope of the 10 meter in diameter SLS payload fairing.
Each RLV-4 Cargo vehicle would weigh approximately 8 tonnes. The 10 meter in diameter payload fairing would add an additional 10 tonnes in weight headed for orbit. Since an SLS Block I would be capable of deploying up to 70 tonnes to LEO, up to 44 tonnes of propellant could be added to one of the vehicles in preparation for a mission.
Alternatively, one RLV-4 Crew vehicle could be launched with one RLV- 4 Cargo vehicle. Before launch, the crew vehicle would be filled with enough propellant to transport a crew to NRHO. The cargo vehicle would simply remain in orbit at LEO until its ready to dock with a payload and be fueled for a mission.
The reusable RLV-4 Cargo vehicle would be able to dock securely with large payloads (up to 10 meters in diameter) subsequently deployed to LEO by the SLS. Payloads deployed to orbit by the SLS would be equipped with flat standardized docking bases configured to securely join with the octagonal payload floor of the RLV-4. Propellant depots deployed to LEO, NRHO (Near Rectilinear Halo Orbit) and eventually on the lunar surface would be used to fuel and refuel the RLV-4 Cargo vehicles.
|Octagon shaped payload floor of notional RLV-4 Cargo vehicle.|
Fueled at LEO with up to 56 tonnes of propellant, the RLV-4 could deploy up to 10 tonnes of cargo to the lunar surface. Alternatively, the RLV-4 could transport up to 30 tonnes of cargo to NRHO where it could then be refueled to transport its 30 tonne payload to the lunar surface.
If the SLS deployed payload has an upper attachment area that could allow an additional RLV-4 to dock then two RLV-4 Cargo vehicles could be utilized for a single cargo mission. This could allow up to 60 tonnes of payload to be transported to NRHO. A single fully fueled RLV-4 Cargo vehicle could deploy up to 50 tonnes of payload to the lunar surface. But two vehicles would be required to deliver a 60 tonne payload to the surface. One vehicle would only travel to lunar orbit and then back to NRHO while the second vehicle would travel to the lunar surface with its 60 tonnes of payload.
So the reusable RLV-4 cargo system would be capable of delivering 10 tonnes to 60 tonnes of payload from the lunar surface from LEO. And that means the SLS could deploy up to 60 tonnes of payload to the lunar surface with a single launch if it used a reusable RLV-4 Cargo transport system.
|Notional RLV-4 Cargo deployed lunar crane for unloading large cargo and for lunar regolith deposition. |
Large lunar cranes might be one of the most valuable initial payloads for the RLV-4 Cargo. Using a davit system, a pair of large cranes could be deployed to the lunar surface. Such electric or hybrid electric (pressurized hydrogen fuel cell/battery) vehicles could be used to unload large and heavy payloads from a large variety of lunar landing craft. If we assume that each lunar crane weighs at least 8 tonnes, lunar regolith could be used to provide an additional 24 tonnes of counter weight. So each lunar crane should be capable of offloading more than 30 tonnes of payload. However, if the iron and other metals that inherently exist within lunar regolith are magnetically extracted to increase the counterweight capabilities of lunar regolith then payloads weighing more than 60 tonnes could be unloaded. Lunar cranes could also be used to deposit regolith within the surrounding walls of large habitats and within the foundation floor for inflatable biospheres and surrounding bio-tori.
|RLV-4 Cargo vehicle carrying twin lunar regolith cranes to be deployed to the lunar surface using davit system. |
Pressurized 8.4 meter in diameter cylinders derived from SLS propellant tank technology could provide multilevel habitats for the lunar surface up to 20 meters tall if deployed within an SLS 10 meter in diameter payload fairing. With a self deploying regolith walls, lunar cranes could provide appropriate radiation shielding by simply dumping lunar regolith within the cavity of the surrounding wall.
|Lunar regolith crane about to remove a Lunar Regolith Habitat from a RLV-4 Cargo vehicle. |
But even longer 8.4 meter in diameter cylinders could be deployed to the lunar surface after being to deployed to LEO by the SLS. 40 meter habitats could be deployed to the lunar surface using the RLV-4 Cargo. Such habitats could be unloaded by large lunar cranes and deployed horizontally to the lunar surface and then covered with lunar regolith bags. The use of the larger horizontal habitats for agriculture could even allow for the growing of orchard trees for the production of apples, oranges, peaches, lemons, etc. The horizontal habitats could also be used for aquaculture, raising shrimp, crabs, fish, clams, etc.
|X-Ray of an SLS propellant tank technology derived Lunar Regolith Habitat|
If the RLV-4 Cargo is used to deploy inflatable Kevlar biosphere and
bio-tori then substantially larger habitats could be deployed. 50 meter
in diameter Kevlar biospheres that are pressurized with half the
atmospheric pressure on Earth could easily be deployed to the lunar
surface by an RLV-4 Cargo. An additional SLS launch would be required
to launch the surrounding 25 meter wide bio-torus. And another SLS launch would be required to deploy the expandable connecting tunnel and regolith base for the biosphere and bio-torus on top.
A 15 meter high SLS deployed lunar regolith hab might provide five spacious 8.4 meter in diameter habitat floor levels (55 square meters per floor).
bottom half of a 50 meter in diameter biosphere could provide up to 9
habitat levels with each floor averaging about 25 meters in diameter
(490 square meters per floor). That would be up to 16 times the floor
area for just the bottom half of the biosphere. The upper half of the
biosphere (the biodome) would provide the astronauts, military personal,
and guest with spacious recreational area with a ceiling up to 25
meters high. Such an area could easily accommodate a large circular
recreational swimming pool 30 meters in diameter. This might also be
room enough to strap on a pair of wings and fly about within the 50
meter wide biodome. The surrounding bio-torus or tori could be used for
agriculture and aquaculture and storage.
|Notional lunar biosphere and bio-torus covered with regolith bags and connected to twin Lunar Regolith Habitats on the sintered surface of a lunar outpost area. |
Once propellant is being produced on the lunar surface, extraterrestrial vehicles like the RLV-4 crew should make it substantially cheaper to travel to the lunar surface after departing the Earth's surface aboard a commercial crew vehicle. If a lunar habitat was deployed to the lunar surface and utilized as a hotel for astronauts, tourist, and military personal, the owners could reasonably charge its guest perhaps $10 million each for a 30 day stay. This, of course, doesn't include the cost of the round trip from Earth to the Moon. If we assumed that an individual habitat was continuously occupied by at least 4 to 8 personal (astronauts, military personal, tourist) then an individual habitat could make between $480 million to $960 million per year in revenue. With up to 16 times the floor area for the bottom half of a biosphere, a single biosphere/bio-tori complex could make more than $15 billion a year in revenue if it were continuously fully occupied with up to 128 people. Providing water, food, and air for the lunar guest would be insignificant if such resources are derived from ice and carbonaceous and nitrogenous resources in the lunar regolith at the poles or from similar resources deep within lava tubes. Assuming a minimum 20 year lifetime for such habitats, such SLS deployed facilities should be highly profitable.
Links and References
Last Tuesday, 52% of Puerto Ricans voted in favor of statehood. The US island territory of more than three million people that has been under US control since 1898.
Thursday, October 29, 2020
Links and References:
Siting Ocean Nuclear Power Plants in Remote US Territorial Waters for the Carbon Neutral Production of Synfuels and Industrial Chemicals
Tuesday, October 27, 2020
Tuesday, October 6, 2020
|Notional SLS deployed RLV-4 Crew lunar landing vehicle with a crew davit deployment system.|
|LOX/LH2 tank configuration in Boeing's Altair lunar lander concept (Credit: Boeing)|
The notional RLV-4 would be octagon shaped like Boeing's Altair lunar descent vehicle concept. But it will use a simplified propellant tank architecture requiring just two LH2 tanks and two LOX tanks, similar to Blue Origin's octagon shaped Blue Moon lunar lander which is basically a smaller-- simplified-- version of of the Altair lunar lander.
|Top view of LOX/LH2 tank configuration for Boeing's Altair lunar lander concept (Credit: Boeing) |
The propellant tanks for the RLV-4 will be derived from Boeing's
super light weight composite cryotank technology with the two large
3.8 meter in diameter hydrogen tanks and and the two smaller liquid oxygen tanks approximately 2.4 meters
in diameter. Both cryotanks will stand nearly 6 meters high within the
interior of the RLV-4 octagon. Gaseous compressed hydrogen will be used to
pressurize the liquid hydrogen tanks and compressed gaseous oxygen for pressurizing the liquid
oxygen tanks during liftoff and trajectory burns-- replacing gaseous helium. Gaseous hydrogen and oxygen
will also be utilized for the vehicle attitude thrusters in this notional vehicle design. So hydrogen and oxygen will provide the propellant, attitude control, and tank pressurization for the RLV-4.
|Notional Boeing 3.8 meter in diameter composite LH2 tank and 2.4 meter in diameter LOX tank.|
The RLV-4 would be somewhat similar in height with Boeing's Altair concept. But it would be able to store more than twice as much
propellant (56 tonnes) thanks to the substantially larger cryotank diameter of the
liquid hydrogen tank and the larger diameter and height of the liquid
oxygen tanks relative to those conceived for the Altair. So the RLV-4
would be capable of accommodating up to 56
tonnes of propellant which would be more than enough fuel to land a 16 tonne crew vehicle from LEO to the surface of the Moon.
The restartable engines for the RLV-4 could be provided by SLS partner,
Aerojet Rocketdyne, who is currently developing the expendable RS-25 engines for
the SLS core vehicle and the RL-10 engines for the upper stage vehicle.
The RL-10 derived CECE engines would be capable of throttling between 104% down to
just 5.9% and would be capable of at least 50 in space starts. So the
CECE engines should be capable of performing at least 12 round trip
missions between NRHO and the lunar surface before having to be
replaced. Using them in pairs would give the RLV-4 engine-out capability, enhancing crew safety.
However, the RLV-4 propellant tanks should be capable
of at least 50 refills (50 round trips if missions between NRHO and the
lunar surface are conducted on a single fueling of propellant). So if
two more engines were added to the RLV-4, 24 round trips could be
possible if only two engines were used during a journey-- while propellant
flow was shut off to the other pair of engines. Replacing the engines
after 24 round trips with four more CECE engines could maximize the
RLV-4's reusability allowing the vehicle to conduct up to 48 round trips to the lunar surface before-- if it is refueled less than 50 times.
|Basic RLV-4 cargo lunar lander with solar panels on four sides of the octagon shaped vehicle and radiators on four sides of the vehicle|
At its corners, the maximum diameter of the RLV-4 octagon would be 8.44 meters with a distance between each opposite 3.23 meter side of the octagon being approximately 7.8 meters. With the legs folded during launch aboard an SLS vehicle within a 10 meter fairing, the RLV-4 could easily fit within the internal 9.1 meter dynamic envelope of the payload fairing.