Newsletter Articles 2022b

July ~ Genetic Engineering

Genetic engineering debuted in 1972 when Paul Berg created a unique virus by combining genes from the monkey and the lambda viruses. Truth be told, we humans have been in the artificial selection business for millennia, breeding domesticated plants and animals for desirable traits. The only difference is that prior to 1972 the attributes were acquired from naturally occurring point mutations, gene duplication or deletion within a species.

In the ensuing decades, DNA both naturally and synthetically derived has been inserted into host organisms to create food crops resistant to herbicides, insect pests, drought, viruses, saline soils, certain heavy metals, and frost. Bacteria, yeast and algae have been modified to produce insulin, pharmaceuticals, biofuels, and remediate oil spills or other environmental contamination. Genetically modified mammalian cell lines produced vaccines.

Early modification methods were inexact. For plants, a plasmid (a DNA ring) was inserted into Agrobacterium tumefaciens bacteria, which then infected small batches of plant tissue. Cells with the desired trait were replicated via tissue culture. Animal cell nuclei were directly microinjected with the pertinent genetic material. Naturally or synthetically sourced plasmids were introduced into microbial cells by chemical carriers or with heat or electric shock. The result was usually a free-floating DNA segment distinct from the host genome, or in the case of Agrobacterium infection, the genetic material was spliced into the host genome in random locations.

But the discovery and deployment of CRISPR technology in 2012 by the all-female research team of Emmanuelle Carpentier and Jennifer Doudna ushered in a new era of highly accurate gene deactivation and/or insertion.

CRISPR is bacterial in origin. It’s a form of microbial immunization against bacteriophages (viruses). Small portions of the virus genome are spiced into the bacterial genome. When transcribed into RNA, this “guide” is incorporated into a nuclease enzyme generated from an adjacent gene. The resulting complex latches onto the invading virus’s matching base pairs, slicing and deactivating the virus DNA.

Carpentier and Doudna paired CRISPR RNA guides with the Cas-9 nuclease to more accurately target different locations within genomes. The CRISPR-Cas9 system has generated a lot of excitement in the scientific community, being faster, cheaper, more accurate, and more efficient than earlier genome editing methods. Today, scientists can tailor the RNA guides to pinpoint specific desired loci within a genome. Dozens of different nucleases can perform single or double DNA strand cuts, and even single base pair substitutions.

This ushered in the current (and future) rush of medical gene therapies. Gene splicing systems allow otherwise missing enzymes and proteins and their lost function to be restored. Disease targets include lymphomas, cancers, retinal degeneracies, muscle dystrophies, immunodeficiencies, hemophilia, and dozens of other conditions.

Gene therapy treatments are somatic. The genetic modifications are not heritable. Genetic engineering of human germ cells (eggs or sperm) is highly restricted and ethically dubious at best. As targetable as CRISPR is, it can and does affect non-target areas of a genome, leading to unintended deleterious consequences for offspring.

Using germline editing for reproduction is prohibited by law in the United States plus more than forty other countries and by a binding Council of Europe international treaty. My descendants may be able to get their “cool gene” treatments, but they won’t pass on their newfound trait to their children. Bummer.

So, what does genetic engineering have to do with Mars? I foresee two applications in the first decade of colonization. The first will be modified food crops.

Perchlorate (ClO4-), toxic to humans and plants, is ubiquitous in Martian regolith. It will need to be removed before crops can be grown. Perchlorate salts are highly water soluble. The easiest method for removal from soil will simply be to flush it out with water. The effluent will still contain biologically useful minerals. And because water itself will be a precious commodity on Mars, it will have to be treated for reuse in irrigation.

Perchlorate can be removed from the effluent by ion transfer. Those who live in regions with hard water are familiar with this. Water softening exchanges calcium ions with sodium, making tap water more suitable for drinking, cooking and bathing. On Mars, perchlorate will be exchanged for less-toxic anions–probably chloride. While less toxic to crops, the effluent will still be saline. So, crop plants may need to be genetically modified to tolerate the salinity.

Fertilizers will be difficult to come by. Nitrogen only comprises 2.7% of the already thin Martian air. By contrast, Earth’s atmosphere is 78% nitrogen. Nitrogen will be expensive on Mars. It must be shipped there from Earth or harvested from the meager Martian atmosphere. Either way, crops grown on Mars must be able to fix nitrogen from the colony air supply, whether directly or by hosting nitrogen-fixing bacteria like legumes do.

I don’t doubt that the first attempts to grow crops on Mars will reveal other deficiencies that we simply take for granted in Earth’s biologically rich soil ecosystems. Crop plants will need to be modified to perform those missing ecological services usually performed by soil microbes.

The other application used in Mars colonies will be gene therapies. Early colonizers must contend with a dual health threat. High doses of cosmic radiation experienced while on the surface(and potentially transiting to and from Mars) will lead to statistically high incidences of lymphomas and certain cancers. Poor availability of return transit, coupled with the months-long travel time, means patients could die of aggressive disease before receiving treatment on Earth.

Gene sequencers, some form of CRISPR lab-in-a-box, and sterile cell incubators to propagate modified immune cells could be shipped to Mars within the first decade.

Human colonizers will face an array of challenges on Mars. But genetic engineering will make a few of them less daunting.

For Further Reading
https://en.wikipedia.org/wiki/Genetic_engineering
https://medlineplus.gov/genetics/understanding/genomicresearch/genomeediting/
https://en.wikipedia.org/wiki/CRISPR
https://www.estherlandhuis.com/uploads/4/0/0/2/40025451/sciam-gene_therapy-nov_2021.pdf
https://en.wikipedia.org/wiki/Gene_delivery
https://www.nature.com/scitable/topicpage/genetically-modified-organisms-gmos-transgenic-crops-and-732/
https://en.wikipedia.org/wiki/Perchlorate
https://en.wikipedia.org/wiki/CRISPR_gene_editing

August ~ Wings of Icarus

 I trust you’ve made the most out of your summer with family and friends, and dodged the worst of the extreme weather and fires that seem to be our new normal.       Here in Central Oregon, we’ve had our share of record-breaking heat waves. But thankfully, most of the fires have remained to our south. The prevailing summer winds have kept the smoke away most days.

On the writing front, I’ve spent this summer alternating between furious bouts of editing my upcoming book Blood Moon, and enjoying some down time with my wife and extended family. As I write this, I’ve even figured out a way to do both at once. At least for writers, I’m convinced the laptop computer is the most important invention since the wheel. At least that’s my story, and I’m sticking with it.

Speaking of stories, many of you have asked, “When will your next short story be released?”
I’m happy to announce, right now! In the past month, I’ve forgone my usual research and article writing in favor of my next short story installment titled, Wings of Icarus.
In this story I introduce Dallas’s former carrier squadron commander Richard “Artie” Shaw, and their relationship. And for those of you who wondered about Dallas’s animosity toward Robbie–the Autotronics autonomous mission AI assistant featured prominently in Crimson Lucre–Wings of Icarus provides that back story as well.

To download your copy of Wings of Icarus, CLICK HERE. I’ve also added the link to my short story library at the bottom of this newsletter, along with the link to Tourist Trap.

Happy reading!
Brian

September ~ Healthcare on Mars

Prospector Base has a sick bay. In Red Dragon, Trudy Trudeau was treated for a gunshot wound there. Looking ahead, Mars explorers and colonists will face a unique set of medical challenges and health risks. What perils will those first arrivals face? And what sort of facilities will they need to survive while up to 170 million miles from home?

“Floating in a most peculiar way” may be a transformative personal experience, but it comes with downsides. The effects of zero-gravity will be acute on the months-long transits to and from Mars. Bone density loss resembling osteoporosis begins on exposure and increases with duration. Recovery can be slow. Astronauts returning from the International Space Station to Earth can take two or three years to return to their pre-flight bone density. It is unknown at this time if the stay on Mars’ 0.38 g’s would continue the loss of bone mass or simply delay the recovery.

Zero-gravity reduces muscle mass, including heart muscle. Without resistance to gravity, muscles atrophy. The heart works less to maintain blood pressure. Blood volume also drops as the body adapts to zero-g. Returning astronauts experience a condition called Orthostatic Intolerance. The weakened heart pumps less blood to the brain, resulting in light-headedness and fainting when standing for extended periods. This will presumably be a risk on Mars, though the low g environment there can be expected to present an intermediate risk to full Earth gravity.

The best mitigation for bone density loss and muscle atrophy is to mimic gravity during the transits to and from the Red Planet, an engineering feat yet to be seriously addressed by either NASA or SpaceX. The addition of resistance and cardio equipment for astronauts on the International Space Station moderates, but does not completely eliminate, the effects of zero gravity.

Mars orbits the sun 40 million miles outside the orbit of Earth, receiving 57% less solar radiation. But because Mars’ atmosphere is so thin, the flux of UV light reaching the surface is roughly equal to that on Earth at sea level. However, the percentage of the shortest wavelength ultraviolet light, UVC, is much higher.

UVC is the most damaging form of UV light but is nearly completely filtered by Earth’s atmosphere. Little or no exposure on Mars would result in severe sunburn and other associated UV damage such as skin cancer and cataracts. Fortunately, very few missions contemplate sunbathing astronauts.

The same suits that protect explorers against the extreme cold and near-vacuum will safeguard against UV exposure. Visor materials already in use in Earth orbit will sufficiently protect users on Mars. However, mission planners must account for rapid ultraviolet light degradation of biological compounds used for pressure suits, habitats, and equipment. The sudden fragility of the Prospector Base dome material in my upcoming book, Blood Moon, is attributable to UV degradation.

Ironically, the efficacy of UV and environmental protection of Mars dwellers could lead to vitamin D deficiency. Humans will take vitamin D supplements on Mars, as astronauts currently must do aboard the International Space Station.

Space is swarming with high energy particles (both charged and uncharged) and rays (i.e., photons). Long term exposure to these particles can lead to radiation sickness, cardiovascular disease, cognitive impairment, cancers and leukemias. But thankfully for us, Earth possesses two features that limit the flux of cosmic radiation that reaches the surface–a strong magnetosphere and a relatively dense atmosphere. Mars unfortunately lacks both. The level of cosmic radiation reaching the surface of the Red Planet is approximately seventeen times that of Earth.

As I noted in my October 2021 issue, the best shielding material for cosmic ray particles is high density polyethylene. The high hydrogen density of this resin provides an effective, though not perfect, shielding material used on the ISS. The top protection for astronauts on Mars will be to site their base underground, either utilizing natural features such as lava tubes, or by constructing permanent subterranean structures.

While it may be possible to adequately shield habitats and vehicles, the suits worn for extra vehicular activities must balance bulky shielding with the need for dexterity. Astronauts must sacrifice some protection from cosmic rays to be able to perform tasks while on the surface. But given the severity of health consequences, they will need to limit EVAs during mid-day when solar particles will be at maximum intensity. Colonists may need to take prophylactic doses of iodine to minimize effects.

Because of the profound isolation on Mars, screening equipment for cancer, heart disease and cognitive impairment must be brought along. Anyone stricken with these diseases will need to be treated in place. The length of time to return to Earth, plus the rigors of the trip itself, makes treatment in place the superior option if the patient is to survive at all. The mission medical equipment must include mini labs that can generate designer pharmaceuticals, and possess the basic raw materials to do so.

No doubt about it. It’s cold on Mars. Even in the garden spot of Hellas Planitia, summer nighttime temperatures can dip down to minus 50 degrees F. Midwinter minimums can drop as low as minus 160degrees F. For reference, carbon dioxide dry ice freezes at minus 109 degrees F. Exposure to such temperatures would be lethal in seconds. Any failure of the heating systems in suits or vehicles could result in rapid onset of extreme frostbite.

Treatment for mild cases is relatively simple–water baths of gradually increasing temperature. But severe frostbite often requires surgical removal of damaged tissues. Prevention will be paramount, but any mission medical facility must be equipped for surgeries. Medical staff must be competent to perform such life-saving procedures.

The dust on Mars is incredibly fine, and pervasive. It will be tracked inside bases and vehicles on the suits worn on extra vehicular activities. If not controlled, airborne particles in these enclosed environments could pose serious health risks. Perchlorates, ubiquitous in Martian soil, are highly reactive oxidizers that can cause lung irritation even in low concentrations. Silica is another known pulmonary irritant and carcinogen. Other heavy metals and toxic compounds found in closed depressions on Earth (think Death Valley) are also likely to be present in Martian soil.

Astronauts cleaning up after an EVA may wear a respirator. Suits and hand-held equipment carried inside should be washed, and the effluent properly treated to ensure fugitive dust does not become airborne. Treatment for exposure could range from steroids or other anti-inflammatories for lung irritation to various chelating agents for arsenic and heavy metal poisoning.

Add to the above list of health risks: cuts, burns, broken bones, and electrocution. Because of a gravity environment, people will fall, vehicles will crash or roll over, accidents will happen. Electrical equipment will require maintenance. In spite of everyone’s best efforts, someone will get hurt. And there will need to be an ample supply of first aid and trauma gear to deal with it.

If we are sending people to Mars, we expect them to return to Earth alive. They will need the equivalent of an army field hospital, plus specialized diagnostic, pharmaceutical and exercise equipment. Due to mass and volume constraints, everything must be miniaturized and optimized for light weight. Most materiel must be prepositioned, including the basic habitat and vehicles. The flight bearing humans will carry food and water to keep the crew alive for the two-to-three-year mission duration, plus exercise equipment, trauma treatment supplies and pharmaceuticals.

To have “the right stuff” to survive the rigors of the Red Planet and return safely home, Mars visitors must possess more than grit and superb health. They must be medically self-sufficient, with world-class clinician(s), diagnostic and pharmaceutical equipment. Think of that the next time you reach for a Band-Aid® in your medicine cabinet.

For Further Reading
https://davidson.weizmann.ac.il/en/online/sciencepanorama/dangers-zero-gravity#:~:text=In%20the%20absence%20of%20gravity%20there%20is%20no%20weight%20load,mass%20within%205%2D11%20days.
https://www.nasa.gov/mission_pages/station/research/station-science-101/cardiovascular-health-in-microgravity/
https://en.wikipedia.org/wiki/Ultraviolet#Solar_ultraviolet
https://www.smithsonianmag.com/air-space-magazine/do-space-station-crews-take-vitamin-pills-180949990/#:~:text=Zeke%20Mazur%20of%20Imperial%20Beach,Johnson%20Space%20Center%20in%20Houston.
https://www.sciencealert.com/these-martian-features-could-serve-as-natural-radiation-shelters
https://www.nasa.gov/feature/space-radiation-is-risky-business-for-the-human-body
http://marspolar.space/files/hellas-basin-preliminary.pdf
https://en.wikipedia.org/wiki/Martian_soil

October ~ Water Electrolyzers

As the world economy transitions from fossil fuels to hydrogen, we’ll need these diatomic molecules of the lightest element. Lots of them. Water electrolyzers will be a critical technology to supply that H2.

Access to hydrogen generated from water will also enable our early attempts to visit and colonize our nearest neighbors: the moon, Mars, and the asteroids.

An electrolyzer is an anode and a cathode (electrodes) immersed in water or steam and separated by a proton-permeable barrier. The anode extracts electrons from the water, breaking the molecule into oxygen and protons (hydrogen ions). These are attracted to the cathode and pass through the membrane, which blocks the passage of O2 and H2gas. Meanwhile, the cathode donates electrons back to the protons, resulting in diatomic hydrogen molecules. H2 bubbles out of the cathode chamber while O2exits from the anode.

Anode Reaction: 2H2O → O2 + 4H+ + 4e-
Cathode Reaction: 4H+ + 4e- → 2H2

 The above electrolyzer constituents constitute a “cell”. 

 Water Electrolyte Cell

Let’s examine the components of a cell in more detail.

Membrane

A Polymer Electrolyte Membrane (PEM)is a solid-state barrier between the electrodes. PEM cells operate most efficiently at 2 volts. But they can utilize a variable current input, making them attractive to pair with renewable power sources that can fluctuate by time of day or weather conditions. Their efficiency leads to reduced operational costs. The membrane’s low gas crossover rate results in very high product gas purity, critical for storage safety.

Cells are stacked, i.e., connected electrically in a series to increase production. Stacked PEM electrolyzers can range in size from small tabletop models to those of 2 MW capacity that fit into a standard shipping container. Multiple units can be hooked up to a common power source to create 10, even 20 or more MW H2 generation plants.

Alkaline electrolyzers utilize a solution of sodium or potassium hydroxide as the electrolyte to separate the electrodes. While not as efficient as PEM technology, they have the advantage of operating at lower temperatures. Extra filtration is required to maintain gas purity. Alkaline electrolyzer cells operate most efficiently at1.5volts.

Solid oxide ceramic electrolyzers work at much higher temperatures, about 700°-800°C, compared to PEMs. They operate at the lowest voltages, but obviously require a greater investment in heating equipment.

Of the three technologies discussed here, most manufacturers are pursuing PEM.
Cathode

Platinum, palladium, rhodium, ruthenium, iridium, and osmium are the materials of choice for electrolyzer catalysts. These elements best resist the acidic electrolyte medium. Their great disadvantage is these metals are rare and pricey. But recent experiments have shown success with iron doped with carbon and nitrogen. In the end, deployment to the moon and Mars will probably be a Trade-off. Which is more expensive, the material cost of the platinum catalyst, or the transportation cost the heavier iron-based alternative?
Power Source

Most power sources for green hydrogen are intermittent and variable. The wind may blow at hurricane force, be a gentle breeze or be calm–all on the same day. Solar intensity varies by time of day, cloud cover and season. Manufacturers follow one of two strategies to maintain constant voltage to their stacks. Current can be regulated outside the stack, but at a loss of efficiency typical of transformers and voltage regulators. Or modulation occurs within the stack by precisely matching the number of cells to the amount of current instantaneously available.

Two potential power sources could be deployed for use on the moon or Mars. A dedicated solid state nuclear reactor would produce a steady voltage and amperage. It could be packaged as a unit with the electrolyzer. The trade-off would be high mass at relatively compact volume. A solar array would weigh less but require greater current modulation. One of comparable capacity to a nuclear fission battery would occupy much more room on board a spacecraft.

The world-wide clean hydrogen generation industry is expected to exceed a trillion dollars market value by the end of this decade. Competition within the water electrolysis sector is fierce. Large US players include companies such as Cummins, Teledyne Technologies, and Plug Power. Europe and Asia are also home to significant manufacturers. Numerous startups are pursuing materials and components with greater durability, electrical efficiency, and lower cost.

Will water electrolyzers go to the moon with Artemis? According to NASA, Shackleton Crater is the prime target for Artemis Base Camp due to its wide variety of lunar geography and water ice. This ice will be a resource for drinking, growing crops and electrolyzing oxygen to breathe and hydrogen (and oxygen) for rocket fuel.

Prior to the first human landing, NASA plans to send the Volatiles Investigating Polar Exploration Rover (VIPER)to the lunar South Pole. The mobile VIPER will discover and map the distribution and concentration of ice that could eventually be harvested to support forays farther into the solar system.

NASA anticipates the establishment of a permanent base by the end of the 2020s. Its power source will be a 10 kW nuclear fission reactor. While not explicitly stated, an experimental PEM electrolyzer will likely be set up as a proof of concept for future Mars missions.

Here on Earth, the US Department of Energy’s goal for green hydrogen production is 10 million tons per year by2030. This is equal to today’s use of fossil fuel-based gray hydrogen, consumed in fertilizer production and heavy industrial processes. Annual production will increase to 50 million tons by 2050, allowing direct replacement of fossil fuels. Numerous demonstrations are operating right now. Many industrial-scale projects will come on-line within the next two years.

While I don’t get into the technical details as I have in this article, PEM technology is prominently featured in my EPSILPN SciFi thriller series books. Look for it in my upcoming novel Blood Moon, available on Monday, November 28th.

For Further Reading
https://www.energy.gov/eere/fuelcells/hydrogen-production-electrolysis
https://www.allens.com.au/insights-news/insights/2021/10/Water-access-for-hydrogen-projects/
https://www.hydrogenfuelnews.com/hydrogen-fuel-cells-ub/8553489/
https://www.hydrogenfuelnews.com/electrolyzer-design-variable/8555454/?awt_a=1jpsU&awt_l=5TI0C&awt_m=hmZVapKEsO5DlsU
https://en.wikipedia.org/wiki/Polymer_electrolyte_membrane_electrolysis
https://en.wikipedia.org/wiki/Artemis_program
https://www.nasa.gov/specials/artemis/
https://blogs.nasa.gov/artemis/2020/10/28/lunar-living-nasas-artemis-base-camp-concept/

November ~ Smartphones on Mars

We’ve come a long way in the twenty years since the Blackberry was introduced in 2002. Remember the Blackberry? It was amazing. I could schedule meetings on a calendar, and read documents ON THEPHONE! The GPS navigation was super-buggy, but I loved the keyboard.

Flash forward to today. Cell phones track and transmit medical data, consummate stock trades, send and receive money or cryptocurrency, record your exercise, stream music, movies, TV, and your favorite video games. You can read and post in social media, host videoconferences, compose and transmit documents. You can navigate on the road or on the trail, manage your internet of things, and purchase everything from event tickets to groceries. Oh, and they still make phone calls.

I won’t even pretend to know all that’s possible with a smartphone today. But if you can think of something todo with or on your mobile phone, chances are there’s an app for that. If there isn’t, there will be in another year or two.

I’m sure you’ve noticed that smartphones play an integral role in all my EPSILON series books. On Mars, the EVA suits come with a sleeve pocket to hold one. They’re connected to the helmet mic and speakers via Bluetooth or comparable technology. A stylus allows for written communication with bulky EVA gloves.

But is it realistic for an away party to communicate with Prospector Base using a smartphone? What about sending and receiving texts from orbiting MGPS (Mars Geo Positioning Satellites)?

Let’s take a quick look at how cellphones function here on earth. They operate in conjunction with a cell–a transceiver with a limited operating range. The phone and tower constantly communicate on an agreed frequency and the tower tracks the signal strength from your phone.

Adjacent towers also track your mobile phone. As you move out of range from the first tower your signal strength increases at a second. The two base stations coordinate with each other, and at some point, your phone gets a message on a control channel telling it to change frequencies. This handoff switches your smartphone to the new cell.

The digital signals are broken up into data packets bearing a unique identifier. This allows the stream of packets to be reassembled as the signal forwards to its intended destination. A tremendous amount of data can be transmitted, even during periods of heavy carrier use.

The different generations of cell service each come with their distinct sets of frequency bands. 3G operates–or rather, operated–at 2100 MHz with a bandwidth of 15 to 20 MHz. 4G uses similar frequencies but with an expanded 100 MHz bandwidth. LTE technology improves the data transmission rate. 5G operates from 2 to 300 GHz. Furthermore, 5G also uses 4G spectrum to enable a lesser service in areas not served by 5G.

What bands do each major carrier use today?
     Verizon: 850 MHz Band n5 (also used for 4G), 1700 to 2100 MHz Band n66 (also used for 4G), 1900 MHz Band n2 (also used for 4G), 3.7 GHz Band n77, 28 GHz Band 261, 39 GHz Band 260.
     AT&T: 850 MHz Band n5 (also used for 4G), 3.4 GHz Band n2, 3.7 GHz Band n77, 24 GHz Band n258, 39 GHz: Bandn260.
     T-Mobile: 600 MHz Band n71 (also used for 4G), 2.5 GHz Band n41, 3.4 GHz Band n2, 3.7 GHz Band n77, 24 GHz Band n258,28 GHz Band n261, 39 GHz Band n260, 47 GHz Band n262.

Is a cell phone’s operating frequency programmable? Yes. Service techs can google a code to gain access to the programming through the keypad. For the rest of us mortals, we do it via the SIM card. It’s why you provide your phone number if you plan to switch carriers, provided your phone is unlocked (i.e., the SIM card isn’t linked to the phone’s serial number).

I’ve used an unlocked 4GMotorola G Power successfully on two different service providers. Here’s a partial list of networks–each with their unique licensed spectra. It could work on: AT&T, Boost Mobile, T Mobile, Cricket, Metro TracFone, U.S. Cellular, Verizon, Xfinity Mobile.

There are at least four transceivers built into phones made today: cellular, WiFi, Bluetooth, and GPS. The MGPS communication frequency used in Crimson Lucre was 400.7 MHz for low data communications. Recall that Allie programmed Dallas’s phone to send text messages for relay to Earth at that frequency. MGPS positioning broadcasted at402.5 MHz. Routing the SMS through that antenna was a reasonable course of action for her.

Let’s look about fifteen years into the future. Mars has no magnetic field, so a compass won’t work for navigation and tracking. Celestial navigation would be useless during the frequent dust storms. A small constellation of GPS microsatellites would be a low-cost solution.

NASA and SpaceEx are engaged in a Space race to see who reaches Mars first. It’s not unreasonable to imagine either or both would save budget by contracting with  cell phone and network routing manufacturers to provide mission mobile communications services.

These phones would link to the base radio, rover WiFi, helmet Bluetooth and a Mars version of GPS. They may also have transceivers to enable transmission to satellites positioned for communication with earlier unmanned missions. The trick will be to route messages seamlessly across these platforms, which is where tech from network carriers would come into play. Use of cell phones on Mars is a near-certainty.

I can see it now. National Cell Service sponsors a Superbowl LXIX halftime commercial that touts your service here on Earth will be as reliable as that on Mars. Oh, the final score? The Arizona Cardinals and the Detroit Lions battle to a 17 – 17 tie.

For further Reading
https://rantcell.com/comparison-of-2g-3g-4g-5g.html#:~:text=THIRD%20GENERATION%20(3G)&text=It%20used%20Wide%20Band%20Wireless,bandwidth%20of%2015%2D20%20MHz.
https://www.verizon.com/about/our-company/5g/what-frequency-5g
https://arstechnica.com/gadgets/2022/09/att-wont-upgrade-older-phones-for-new-5g-bands/
https://www.t-mobile.com/support/coverage/t-mobile-network#:~:text=Ultra%20Capacity%20(UC)%205G&text=Band%20n41%20(2.5%20GHz),Band%20n261%20(28%20GHz)
https://www.etopuponline.com/blog/can-you-buy-a-sim-card-for-an-existing-cell-phone

December ~ Zero Carbon Aviation

My wife and I recently returned from a vacation to Maui. We flew nearly 5,800 airmiles round-trip. According to figures used by the World Bank the two of us generated just over 2 metric tons of carbon dioxide, almost 4,500 lbs!

Worldwide, commercial aviation produced 915 million metric tons of CO2 in 2019. If you liquified all that CO2and loaded it into typical 30-foot-long propane delivery trucks, at 13.45metric tons of CO2 per truck, it would fill 68,029,740 vehicles. Parked nose-to-bumper, the line would wrap around the Earth’s equator 15 ½ times!

Given these kinds of numbers, the airline industry is a significant contributor to atmospheric carbon dioxide and resultant climate change. Experts agree it accounts for about 2.4% of total annual carbon dioxide emissions. Established airplane manufacturers and a plethora of start-up companies are exploring no-carbon fuel options for commercial aviation.

There are three basic zero-carbon options available to power commercial flights: battery electric (BE), hydrogen fuel cell electric (HFE), and direct hydrogen combustion (HC). I’m omitting alternative carbon-based fuels only because of the difficulty of scaling up production in a meaningful way.

Like battery electric vehicles, BE planes rely on a lithium-based power pack to run an electric motor. Instead of turning a wheel, the electric motor turns a propeller.
BE designs are highly constrained by the power density of the batteries. Lithium-ion batteries store a large amount of power but discharge it slowly. This limits use of these batteries to small regional aircraft. With larger airframe designs the battery mass quickly exceeds the ability to generate lift, making them impractical. Research is focused on reducing battery weight while increasing power output.

So far, engineers have widened or lengthened the fuselage to account for battery storage, rather than place the batteries in the wings. Around 100 electric aircraft designs are currently under development worldwide.

Instead of using a battery for energy storage, HFC designs rely on fuel cells to run electric motor-driven propellers. In the reversal of water electrolysis (October ’22 Just Over the Horizon). Hydrogen is catalytically combined with oxygen within the fuel cell to form water, releasing electrons in the process. Hydrogen has an energy density of 35,000 watts per kilogram, giving fuel cells a big advantage over batteries which release their stored energy more slowly.

The challenge for HFC is designing and incorporating bulky liquid hydrogen cryogenic storage tanks. Like BE designs, fuel will be stored within the fuselage rather than in the wings. But due to the lighter mass of liquid hydrogen, greater range and payloads can be realized.

Hydrogen combustion utilizes hydrogen rather than hydrocarbon fossil fuels to generate thrust. Liquid hydrogen, cooled to −253 °C, has an energy density 4.1 times lower than jet fuel (8.5 MJ/L verses 35 MJ/L). Just as the case when compared to batteries, the lighter mass of hydrogen ultimately allows for greater speed and range than fossil fuels. Like BE and HFC technology, HC airframes must be designed with larger volume fuselages to accommodate the higher volume of fuel required.

Here is a sampling of HC development leaders and the status of their tech. MagniX is developing electric motors for aviation. On May 28, 2020, a MagniX-powered nine-passenger Cessna 208B eCaravan flew on battery electric power. The company is working toward FAA certification for commercial operation for its 640 kW (850shp) Magni650 engine.

On September 7, 2022, BE startup Eviation flew a 9-passenger prototype electric plane driven by MagniX motors for 8 minutes to an altitude of 3,500 feet. The plane was designed and built to demonstrate the potential for an electric commercial commuter aircraft flying a few hundred miles between cities at an altitude of around 15,000 feet. It was powered by just over 21,500 small Tesla-style battery cells that, at just over4 tons, make up fully half the weight of the carbon composite airframe.

Another startup, ZeroAvia, builds a 600kW HFC powertrain for 10-20 seat plane. They  installed two ZA600 hydrogen-electric powertrains aboard a twin-engine 19-seat Dornier 228 aircraft at its headquarters in Hollister, California. It will serve as the testbed for working with the FAA ahead of the ZA600 engine’s planned certification in 2024.

In 2022, American Airlines signed an MoU for an order of as many as 100 of the H2-powered plane engines for eventual use in its regional fleet. Aircraft leasing company MONTE will purchase up to 100 ZA600 powertrains to be installed on existing and new Cessna Caravan, DHC-6 Twin Otter, Dornier228 and HAL-228 aircraft.

In September 2020, Airbus presented three ZEROe hydrogen-fueled concepts proposed for commercial service by 2035: a100-passenger turboprop, a 200-passenger turbofan, and a futuristic turbofan-powered blended wingbody. In February 2022, Airbus with partner CFM International, announced a demonstration of a liquid hydrogen-fueled GE Passport turbofan with modified combustor, fuel system and control system. Mounted on a fuselage pylon on a prototype A380, the first flight is expected within five years.

Rival Boeing has acknowledged the potential of the technology but recently cut research and development in an effort to return to profitability after its 737 Max and 787 production disruptions.

Pratt & Whitney, Rolls-Royce and GE are all developing hydrogen turbofan engines, with the expectation of incorporation into major passenger aircraft by 2035.

What obstacles remain to full adoption of zero-carbon aviation?

Battery weight. Heavier lithium-ion electrolyte tech is being replaced by lithium-polymer. In addition to lighter weight, L-P offers higher output. Even so, BE will probably always be restricted to regional commercial aviation, general aviation, and EVTOL flying taxis.

Ramping up production of green hydrogen will take time. By 2030 total annual production is projected at about 5.2 million metric tons. By 2050, when demand and production are expected to match, production will reach 500-680 million metric tons. The percentage of green hydrogen available to meet aviation demand in 2030 will be in the single digits.

Aviation will have to compete with cement, steel and fertilizer manufacturing, transportation, plus the general grid. It will have to be augmented by alternate green aviation fuels, de minimus use of gray/blue hydrogen and fossil fuels until green hydrogen production capacity catches up with demand some twenty years later.

Many of the hydrogen hub proposals submitted to the Department of Energy, seeking a share of the $7 billion program, will knit together green power hydrogen production sites with industrial sites, utilities and airports via pipelines, rail and shipping. Airports are already announcing commercial agreements with vendors to provide cryogenic storage and delivery to aircraft.

In the future look to see tanker trucks resembling propane delivery trucks fueling up HFC and HC aircraft.

Let’s look about fifteen years into the future. At best, commercial zero-carbon aircraft manufacturers will be five years into production. Airlines may restrict the few hundred HC aircraft to specific hubs that can acquire and deliver the limited supplies of green hydrogen. BE and HFC regional aircraft, ten years into certification, could enjoy a greater market penetration than the larger aircraft. Smaller regional airports may offer deliveries by offsite vendors.

What if you live near an airport? HC aircraft won’t necessarily be quieter than the most modern jet fuel powered craft, but they’ll be cleaner. Hydrogen combustion produces none of the soot, and a small fraction of the NOx pollution of jet fuel. Regional and general aviation craft will be noticeably quieter.

Will these first steps by commercial aviation reduce CO2 emissions and the worsening resultant climate changes by 2037? Probably not. Given the expected world-wide growth in commercial aviation, the carbon reductions will barely offset growth. But other sectors of the economy will have decarbonized farther. By 2037, we might realize diminishing annual global greenhouse gas emissions. We’ll finally beheading in the right direction.

For further Reading
https://en.wikipedia.org/wiki/Embraer_E-Jet_E2_family
https://en.wikipedia.org/wiki/Electric_aircraft
https://en.wikipedia.org/wiki/Hydrogen-powered_aircraft
https://nap.nationalacademies.org/catalog/26512/preparing-your-airport-for-electric-aircraft-and-hydrogen-technologies
https://www.magnix.aero/services
https://www.seattletimes.com/business/boeing-aerospace/first-u-s-all-electric-airplane-takes-flight-at-moses-lake/
https://www.airbus.com/en/innovation/zero-emission/hydrogen/zeroe
https://www.energy.gov/oced/regional-clean-hydrogen-hubs
https://www.gminsights.com/industry-analysis/green-hydrogen-market