Friday, August 26, 2022

ARTEMIS I

Media Briefing: Artemis I Launch Status (August 30, 2022)

Monday, July 4, 2022

The Functional and Economic Value of Repurposing Spent SLS Core Stages


Notional SLS derived Dry/Wet orbital habitat at LEO with more than 4000 cubic meters of pressurized volume. A notional  crewed reusable REUS-LV approaches the habitat after a voyage from a similar habitat at NRHO.

by Marcel F. Williams
 
Deploying large habitats, depots, and reusable interplanetary vehicles to LEO is probably the most logistical and economically efficient way to utilize the new Space Launch System (SLS). But the basic SLS Block I configuration capable of deploying up to 70 tonnes to LEO also comes with an added benefit. The spent core stage of the  SLS  could also arrive and remain in low Earth orbit fully intact. 

With a pressurized volume exceeding 916 cubic meters, $165 billion (in current dollars) the International Space Station is considered to be the most expensive structure ever built by humanity. But the pressurized volume of a spent  SLS core stage would exceed 3000 cubic meters (more than three times the pressurized volume of the ISS). 

If SLS core stages were allowed to remain in orbit, it could be retrofitted by astronauts from a nearby space station or space vehicle to accommodate enormous amounts of water, or cryogenic propellants, or the pressurized atmospheres of habitats. This, of course, would add significantly more economic value to each SLS launch.   

X-Ray of the SLS core stage hydrogen and oxygen tank (Credit NASA)

 

Microgravity Habitats

Polls suggest that 42% of Americans would like to travel into space. But  there are only about 52,000 people, worldwide, who could actually afford the $25 to $50 million cost of space travel. Still that suggest that perhaps 22,000 people who would like to travel into space-- actually have the funds to to do so. Annually, if just 10% of that group paid to visit an orbiting space hotel it would  require more than 400  commercial launches every year. This, of course, doesn't include the number of unmanned launches needed to provide such orbital facilities with the food and water and other supplies.  But even if a mere 1% of the super wealthy who desired to travel into space purchased rides to a space habitat every year,  that would require 44 to 55 private commercial launches annually.

Of course, additional revenues could be accrued by providing accommodations for astronauts from NASA, the Department of Defense and astronauts from foreign space agencies.  


Cramped conditions inside the interior of an ISS crew module (Credit NASA)

Relatively spacious interior of  6.6 meter in diameter Skylab space station (Credit NASA)


If the owner of a space hotel charged  $500,000 a day for each day their facility accommodated a  visiting astronauts or space tourist resided in their facility (including arrival and departure days) then they would make $5 million for a ten day stay. For a six member flight crew that would be $30 million dollars in revenue in just ten days.  If such a facility was continuously occupied by six individuals on average then  the orbiting hotel would make $1.095 billion (nearly $1.1 billion a year).

An SLS core stage retrofitted with docking adapters and airlocks could be latter attached to habitat modules deployed by the SLS or other launch vehicles. This could allow pressurized habitats deployed by private companies or national space agencies to attach their modules to a purchased retrofitted SLS spent core stage, guaranteeing them and additional 3000 cubic meters of pressurized space-- no matter how large of small their habitat modules are.

A  spent SLS core stage retrofitted with docking airlocks sold for $5 billion could be paid off in less than five years if the facility was continuously occupied by at least 6 astronauts or tourist. A 20 to 30 year lifetime might produce $21 to $32 billion of revenue for the SLS core stage enhanced habitat.

 

Notional SLS derived Dry/Wet orbital habitat at NRHO with more than 4000 cubic meters of pressurized volume. A notional crewed reusable REUS-LV is docked at the habitat before transferring a six person crew to the surface of the Moon.

Water & Sewage Depots

Water, of course,  is an extremely valuable commodity in extraterrestrial environments. Water can be used to wash, to drink, and to prepare food for its human occupants. Electrolysis can be used to convert water into  oxygen to create breathable atmospheres.   And the oxygen and hydrogen produced through the electrolysis of water can also be liquefied and utilized for rocket propellant. 

Since a spent SLS core stage would have two empty tanks, one tank, in theory,  could be used to store enormous quantities of water. This water  could later be transported to nearby orbiting habitats or to propellant producing orbiting depots. 

Human occupied orbiting habitats will also produce substantial quantities of waste water in the form of sewage. So the second SLS core stage tank could be used to store this sewage-- almost indefinitely. Ultimately this sewage could be used as another source of water.  Methane could also be produced from the sewage to fuel liquid methane fueled interplanetary spacecraft. 

Nearly a tonne a day of waste water could be produced for six occupants aboard a space habitat saving more than 300 tonnes of water a year, avoiding perhaps $1.5 billion a year in cost if such water had to be brought from the surface of the Earth.  Assuming a 20 to 30 year lifetime for the depot, that could be $30 to $45 billion in water transport savings from Earth.                                                                                                                                                                                                                                                                                               

Liquid Oxygen and Liquid Methane Depots

Nine tonnes of water for a propellant producing depot would produce one tonne hydrogen propellant plus six tonnes of oxidizer-- leaving two tonnes of oxygen as a waste product. However, a spent SLS core stage could be used to store the excess oxygen.  The spent SLS core stage could be retrofitted with solar panels to keep the oxygen refrigerated. Interplanetary  vehicles launched from Earth could arrive in orbit with only fueled with hydrogen or methane, utilizing the excess oxygen stored by the SLS core stage for propellant oxidizer.

The second tank in the SLS spent cores stage could be used to store liquid methane produced from the sewage stored in water and sewage depots.

So every 90 tonnes of water sent into space for propellant production (~$450 million),  20 tonnes ($100 million) would be wasted-- if the excess oxygen produced through electrolysis  is not stored away to be later utilized. So 900 tonnes of water sent into orbit a year for propellant production could save $1 billion a year in propellant for extraterrestrial missions.


 Rotating Crop and Orchard Plantations 

With an interior diameter of approximately 8.4 meters, the two empty tanks of a spent SLS core stage tanks could accommodate two large areas for growing crops or trees. The cylinders would have interior surfaces of 285 meters squared for the empty oxygen tank and 886 meters squared for the empty hydrogen tank. The domed end caps could be used for vineyards (growing grapes). Even with soil (presumably originating from the lunar surface) a meter deep, the two tanks should be able to grow enough food to feed at least 12 people a year. 

Dwarfed trees between 2.5 to 3 meters tall could be used to grow apples, oranges, lemons, peaches, pears, plums, cherries, olives, etc. Banana plants could also be grown. 

Crops such as wheat, corn, rice, potatoes, yams, sugar beets,  tomatoes, lettuce, pineapples, etc. could also be grown.

The bio-waste from the agricultural foliage could also be of value. Pyrolyzed into syngas,  hydrogen or methane could be produced for rocket fuel and the waste CO could be converted into CO2 for growing trees and crops. 

A thruster module could be attached to the top of the spent core stage in order to make the structure spin along its axis, producing artificial gravity within the interior of the tanks. Remote controlled robots could be used to manage the orchards and crops. Humans in pressure suits could periodically visit the space farms under microgravity conditions to retrieve fruits and vegetables or to bring in more water and equipement by simply using the thrusters to hault the structure's rotation. Entry docking ports into the two tank areas could be retrofitted into each tank area the same way it would be done for the habitat core stages that were retrofitted to be habitats.   

Solar panels and cooling fins  could be attached to the thruster unit for providing thermal control and  electricity and interior lighting for a space farm.

If eight tonnes of food could were grown a year to feed up to 12 people, $40 million a year could be saved in food exports from Earth. This is perhaps $800 to $1.2 billion --in food import savings over the course of a lifetime for the spent SLS core stage tanks.


Notional EUS derived REUS-OTV with connecting ring for operations with a second REUS-OTV vehicle

 

Exploiting Residual Fuel

Several tonnes of propellant would be required to de-orbit the SLS core stage. But the residual fuel used to de-orbit the core stage sending it into the Earth's atmosphere could be extracted by orbiting propellant depots to be stored and saved to fuel vehicles destined for beyond LEO missions. This could amount to $5 million per tonne of fuel saved.

 

Beyond LEO Deployment 

While the SLS could deploy spent core stages to LEO, a notional REUS (Reusable Exploration Upper Stage) used in pairs could be used to redeploy the core stage practically anywhere within cis-lunar space (NRHO, DRO, L3, L4, and L5) and even into orbit around Mars and Venus.


Links and References

Deploying a Ginormous SLS Derived Dry/Wet Workshop Habitat with a Single SLS Launch

Space Launch System

Commercial Launch Demand to Private Microgravity Habitats at Low Earth Orbit

The Logistical Viability of an SLS EUS Derived Reusable Lunar Crew Lander

All about dwarf fruit trees

Cis-Lunar Gateways and the Advantages of Near Rectilinear Orbits



Tuesday, June 21, 2022

Tuesday, May 10, 2022

The Logistical Viability of an SLS EUS Derived Reusable Lunar Crew Lander


Notional reusable EUS derived REUS-LV/Crew vehicle descending to the lunar surface using side thrusters for the final descent and soft landing
 
by Marcel F. Williams

The current development of the Exploration Upper Stage (EUS) for NASA's Space Launch System offers Boeing Aerospace an opportunity to produce reusable variants of the spacecraft that could greatly enhance the capability of Boeing's super heavy lift vehicle system. 

 

 Reusable Lunar Crew Lander

By simply adding a pressurized crew module at the top of the spacecraft and landing gear at the bottom of the vehicle could allow the EUS to land humans on the surface of the Moon. I will refer to this notional crew landing EUS variant as the REUS-LV/Crew. 

Replacing gaseous helium with gaseous oxygen and hydrogen for pressurizing liquid oxygen and liquid hydrogen tanks should  allow the REUS-LV to be reused at least 50 times. The gaseous hydrogen and oxygen could also power thrusters for attitude control.   However, with  RL 10 engines capable of only 50 starts, reusability for such a vehicle might be limited to only six round trips between  LEO and the lunar surface.   

 

Artist depiction of an expendable  EUS for the Space Launch System (Credit NASA)

NASA is intent on establishing its deep space Gateway at an NRHO (Near Rectilinear Halo Orbit), a seven day polar orbit around the Moon. The  human occupied Gateway habitat  would allow 12 hour trips to the lunar surface every seven days.  A weeks stay on the lunar surface would also allow a return to NRHO in just 12 hours time. 

Assuming a dry mass of 23 tonnes for a crewed version of the REUS-LV, the space vehicle should be cable of round trips to the lunar surface utilizing less than 70 tonnes of propellant. So substantial amounts of additional payload could be deployed with crewed missions to the Moon if 113 tonnes of the vehicle's total fuel capacity is utilized.   

Private commercial launch vehicles could transport passengers to the  REUS-LV/Crew spacecraft orbiting independently  at LEO or docked at a LEO orbiting space station. 

 

Notional reusable REUS-LV/Crew landing vehicle for lunar operations

Once the REUS-LV/Crew vehicle is on the Moon, a davit crane system could be used to lower astronauts, vehicles, and other equipment to the lunar surface and to retrieve astronauts and lunar material later for transport back to the NRHO Gateway. Solar panels positioned on four of the walls surrounding the LOX tank would provide electricity for the crew module plus electric power to keep the hydrogen and oxygen liquefied using the thermal radiators to assist its cryocooler refrigeration systems. 

 

Orbital Propellant Depots

Two REUS-LV/Crew vehicles could be deployed to LEO with a single SLS launch. But propellant depots would be required to fuel the vehicles at LEO and at NRHO in order to conduct crewed missions to and from the lunar surface and to return the spacecraft back to LEO. So the deployment of two propellant manufacturing water depots at LEO and at NRHO would be necessary for crewed lunar missions. 

Two REUS derived vehicles (REUS-OTV/Depot) could be utilized as propellant producing water depots capable of storing up to 150 tonnes of water for the production of  113 tonnes of LOX/LH2 propellant. 9 tonnes of water contains approximately 8 tonnes of oxygen and one tone of hydrogen. But only 7 tonnes of propellant could be manufactured from 9 tonnes of water since rocket fuel would require a ratio of 6 tonnes of oxygen per ton of hydrogen.   So each depot would be capable of storing approximately 16 tonnes of LH2 plus 97 tonnes of LOX) while wasting 32 tonnes of liquid oxygen. 

However if only 113 tonnes of water is converted into 97 tonnes of liquid oxygen and 13 tonnes of hydrogen then 100% of the water could be utilized as fuel if an  REUS-LV vehicle initially arrives at LEO from Earth with at least 3 tonnes of liquid hydrogen propellant. Two REUS-LV/Crew vehicles would only weigh 46 tonnes. And with an additional six tonnes of liquid hydrogen propellant, would still only be 52 tonnes of payload mass for a basic SLS vehicle capable of deploying at least 70 tonnes to LEO. Fully fueled with LH2, the first REUS-LV/Crew vehicles launched to LEO could require no liquid hydrogen from the LEO depot at all, only its liquid hydrogen.

Water could be continuously supplied to propellant producing depots at LEO by various private American launch systems (Space X, the ULA, and Blue Origin) who have vehicles  that are either currently operational or are very close to being operational: 

Falcon Heavy (Space X) - 63 tonnes to LEO

New Glenn (Blue Origin) - 45 tonnes to LEO

Vulcan-Centaur (ULA) - 27 tonnes to LEO

 

During the first SLS launch of two propellant depots to LEO, private launch companies could supply one depot with enough water to produce propellant that can be transferred to the second depot to deploy itself plus its solar array to NRHO. 



EUS derived propellant producing water depot approaching orbiting solar power plant @ NRHO where it will use photovoltaic power to electrolyze water into LOX and LH2.
 
Private launch vehicles could also be used to deploy water directly to NRHO once the propellant producing depot arrives. But it would be much cheaper and efficient for private launch companies to simply focus on supplying water to LEO.  Large reusable REUS-OTV (Orbital Transfer Vehicles) could transfer water from LEO to depots located at NRHO much more efficiently.  A single SLS launch would be required to deploy two such EUS derived vehicles into orbit probably with their LH2 tanks already filled with liquid hydrogen.
 


REUS-OTV plus optional  interstage connection ring for joining two OTV vehicles together. Such vehicles could be used to transport 60 to 120 tonnes of water and other  payloads between LEO and NRHO and to various lunar orbits and Earth-Moon Lagrange points.


Crewed Missions to the Moon and Reusability
 
For crewed missions to the lunar surface, An REUS-LV/Crew vehicle  would be fueled with propellant at LEO and then travel  four days  to the orbital outpost at NRHO. After arriving at NRHO, the REUS-LV/Crew vehicle would then be fueled with additional propellant at   for its round trip journey to the lunar surface and then back to NRHO. Once the crew returns to NRHO, only the minimum amount of propellant would be required to return the REUS-LV/Crew spacecraft back to LEO. 
 
 
Reusable REUS-LV/Crew vehicle docked at a notional single launch SLS derived MegaStation at NRHO. The notional EUS derived vehicle would be cable of round trips between NRHO and the lunar surface on substantially less than a full tank of LOX/LH2 propellant.   REUS-OTV vehicles could be used to deploy the habitat modules and the pressurized spent SLS core stage from LEO to NRHO.
 
 
RL-10 engines can be manufactured with a capability of 50 restarts. So a single REUS-LV/Crew vehicle should be capable of at least 6 round trips to the lunar surface starting and returning to LEO. The REUS-LV/Crew vehicle would be capable of  12 round trips if the spacecraft  is only utilized for trips between NRHO and the lunar surface. 

Two reusable REUS-LV/Crew vehicles could be deployed to LEO with a single SLS launch. And each vehicle deployed would be capable of at least 12 round trips between LEO and NRHO. So a single SLS launch could allow 12 round trips to the lunar surface-- if water can be supplied to LEO and then to NRHO. This would require two more SLS launches to deploy two solar powered propellant depots and two REUS derived orbital transfer vehicles (REUS-OTV) to transport water from LEO to NRHO. So three SLS launches would be required for 12 round trips to the lunar surface (four potential round trips to the lunar surface per SLS launch). 


Lunar Depots

REUS derived propellant producing water depots with landing gear could also be  deployed to the lunar surface with photovoltaic solar power units. If water ice resources are exploited at the lunar poles then propellant could be produced on the Moon. The REUS-LV/Crew vehicle could be fueled with propellant at LEO and travel directly to the lunar surface. And the same REUS-LV/ Crew could later be fueled with lunar propellant for its return trip directly to LEO. 

Reusable REUS-LV/Crew vehicle docked at a notional single launch SLS derived MegaStation at NRHO. The notional EUS derived vehicle would be cable of round trips between NRHO and the lunar surface on substantially less than a full tank of LOX/LH2 propellant.   REUS-OTV vehicles could be used to deploy the habitat modules and the pressurized spent SLS core stage from LEO to NRHO.

 Alternatively, propellant from Earth could be substantially reduced for lunar missions if tankers supplied water from the moon to NRHO depots. REUS-LV/Crew vehicles could then return to LEO using LOX/LH2 propellant produced on the Moon. 

  

Reusable Lunar Hopper  

 

The delta-v and travel times for possible crewed suborbital hops on the lunar surface. Fueled with liquid hydrogen and oxygen at a lunar base, a notional REUS-LV/Crew vehicle would be capable of traveling to any region on the surface of the Moon in less than an hour and return back to the lunar outpost on less than  a single tank of fuel.

 

Supplied with propellant on the lunar surface, the REUS-LV/Crew could also be used as a lunar hopper that could travel to any region on the surface of the Moon in less than an hour. The vehicle would also carry enough fuel to return to the lunar outpost where it was fueled in less than an hour.  With four trajectory burns for each round trip, each REUS-LV/Crew vehicle could travel to 12 regions on the lunar surface. So a single SLS launch could potentially explore 24 regions on the lunar surface if REUS-LV/Crew vehicles are refueled with lunar propellant. 

 

Repurposing Decommissioned Landing Vehicles 

REUS derived vehicles could still be put to good use after they are decommissioned from their original task.  REUS-LV/Crew vehicles that are no longer safely capable of crewed flights could  be repurposed for storing substantial quantities of water mined from the lunar ice and for storing sewage accumulated from the inhabitants of lunar outpost. With both a hydrogen and oxygen tank, substantial quantities of  water and sewage could be stored in the two different tanks of one vehicle.   The decommissioned vehicles could also be used to store excess oxygen from the production of propellant. LOX and LH2 could be stored in decommissioned spacecraft to produce electric power during the lunar night using fuel cells. Such fuel cells would not only produce electricity from the hydrogen and oxygen-- but also water. 

Decommissioned vehicles could also be used as temporary outpost in lunar regions of particular interest. They could be transported to their lunar locations by electric powered lunar cranes. And regolith bags could be deployed around the vehicle's habitat modules for additional protection against cosmic radiation and micrometeorites. 

Decommissioned REUS-OTV vehicles in orbit could be used in a similar fashion at NRHO for  storing water, or excess oxygen from the production of propellant. 


Deep Space Robotic Missions to Phobos and Deimos

At NRHO, the  REUS-LV/Crew vehicle could also be used for-- unmanned-- round trip  robotic missions to the moons of Mars. The delta-v requirements for such round trip missions between NRHO and the martian moons  would actually be less than round trip missions between NRHO and the lunar surface.  So a robotic REUS-LV would be fully capable of traveling to the surface of Deimos or Phobos and returning to NRHO with substantial quantities of rocks and regolith from those two tiny martian moons.  Roving vehicles could also be left behind that could be used to extensively explore each of the martian moons. The REUS-LV davit system could easily lower and retrieve such vehicles after landing on those tiny worlds.

 

 Links and References

Rocket to the Moon: What Is the Exploration Upper Stage?

Exploration Upper Stage

EUS on the Moon

 RL 10 Engine

 CECE: A Deep Throttling Demonstrator Cryogenic Engine
for NASA's Lunar Lander

Cis-Lunar Gateways and the Advantages of Near Rectilinear Orbits

Realistic Near-Term Propellant Depots: Implementation of a
Critical Spacefaring Capabilit

Large-Scale Demonstration of Liquid Hydrogen Storage With Zero Boiloff for In-Space Applications

Delta-v Calculator

Delta-v Budget

Deploying a Ginormous SLS Derived Dry/Wet Workshop Habitat with a Single SLS Launch

Travel on Airless Worlds

Reusable Hoppers and Orbiters for Rapid Lunar Transportation and Exploration


Monday, April 4, 2022

Higher Levels of Racism and Prejudice Associated with a Disbelief in Human Evolution

Homo erectus pekinensis
 

According to University of Massachusetts Amherst research published in the Journal of Personality and Social Psychology, a  disbelief in human evolutionary biology in the US was associated with higher levels of racism and prejudice including  support for discriminatory behavior against immigrants, people of African ancestry,  and the LGBTQ community. Similar patterns of racism and prejudice have also been associated with lack of belief in human evolution by individuals living in Europe and in the Middle East.

Links and References

Bigotry and the human–animal divide: (Dis)belief in human evolution and bigoted attitudes across different cultures.

Disbelief in human evolution linked to greater prejudice and racism




Thursday, January 27, 2022

Monday, January 3, 2022

Crime & Punishment

Living facilities in a California State Prison(Credit Wikipedia)
 

by Marcel F. Williams

Per capita, most victims of crimes are people of color. Just check the stats. So simply allowing hardworking people of color to continue to be disproportionately victimized by the anti-social individuals in their communities is obviously no solution to crime and prison overcrowding. And simply dumping former inmates back into the  environments that created them in the first place tends to create a lot more crime rather than reducing it!

Are there too many people in prison? Yes! But that's because prisons now house hundreds of thousands of mentally disturbed individuals   who use to sequestered away in mental institutions for the criminally insane. But America shut down most of those institutions decades ago which is part of the reason why we also have so many homeless people on our streets today. 

America  also abandoned any type of serious rehabilitation in US prisons  decades ago. So we make it very difficult for former inmates to get jobs after they are out. What former inmate wants to tell a potential employer that he use to be in prison? And what employers wants to hire such an individual?

But simply feeling sorry for convicted felons and letting them out of prison early doesn't solve America's high crime problem.

The solution, in my opinion, is the rehabilitate convicted felons in prison and then put them in an environment where they are most likely to be productive citizens and not to return to crime. 

 So, the solution, in my opinion,  is:

1. Prison work programs where prisoners work for private and public institutions for half the state minimum wage with 60% of their income going back to the government  with the inmate only getting payed 40% of half the minimum wage as a salary. The money earned by the prisoner would be placed in a private bank account with the prisoner having absolutely no access to his or her funds-- until they are out of prison. This would allow former felons  to have substantial amounts of money in the bank once they are out of prison making it economically a lot easier for them to financially reintegrate back into society.

2. Private companies that employ former felons should get an annual payroll tax rebate from both the   Federal and State governments for every former felon that they employ.

3. Sentences for convicted felons should be a combination of prison time plus  temporary exile to designated Sanctuary Cities.

A Sanctuary City would be a walled working city within each US state or territory designated to accommodate domestic and foreign refugees (illegal aliens) and former prison inmates transition back into society. Such Sanctuary Cities would be declared by Congress as international territories under the jurisdiction of the Federal government. Anyone with a US passport or US visa would be allowed to visit, depart,  or even live and work within the walls of a Sanctuary City. Former felons would not be given passports to leave the Sanctuary City until they have completed their court mandated time within a Sanctuary City.

Felons who commit non-violent crimes should be given two years of exile within a Sanctuary City after they serve their prison sentences, IMO. Violent criminals would be exiled for five years within a Sanctuary City after serving their prison sentences.

Ex prisoners would also have full access to the money in their bank accounts once they are exiled to a Sanctuary City. This would allow states and the Federal government to shorten prison sentences while still not immediately dumping former prisoners right back into the environments that created their criminal activity in the first place.

Sanctuary cities would specialize in employing former prisoners with full workers rights and pay and would serve as test environments to see if a former prisoner has been truly rehabilitated. But rehabilitation through payed labor, providing tax incentives for employers to hire former felons, and serving the last few years of a felony sentence within the confines of designated Sanctuary Cities should dramatically lower the crime rate in most cities and towns in America, especially in minority neighborhoods, increasing public safety while catalyzing new economic growth and prosperity in America. 

I will elaborate a lot more on my Sanctuary City idea in future post since I believe that this concept would be the best way to  humanely deal with illegal immigration, domestic transients, and US prisoners transitioning back into society! 

 

References and Links

 

Number of murder victims by race in the US in 2020

Racism in Rape

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