Are we on the right track for space settlement?

Artist depiction of an O’Neill cylinder from the novel K3+. Credits: Katie Lane (Full distribution rights reserved by Erasmo Acosta)

Erasmo Acosta thinks we might be headed in the wrong direction, that we may be suffering from planetary chauvinism and the better way may be to colonize space with O’Neill cylinders. He makes his case in a post on the Predict section of Medium. SSP has long been a strong proponent of free space O’Neill-type settlements, the advantages of which are numerous, not the least of which is 1G artificial gravity to prevent detrimental human health issues that may arise for occupants of colonies with lower gravity on the Moon or Mars. Such space settlements would house millions of people in perfect 70 degree controlled weather without the threat of natural disasters.

Jeff Bezos has advocated for this philosophy with the aim of moving heavy industry off world and preserving Earth’s environment for “residential zoning”. Recent developments seem to indicate he may be spending more of his time focusing on the realization of that vision.

Acosta, a retired software engineer, feels so strongly that O’Neill cylinders will be the preferred mode of space settlement he wrote a novel called K3+ which depicts a future in the next century where humans will be living in thousands of O’Neill cylinders in a “post-scarcity” civilization of virtually unlimited resources. Acosta envisions Mercury as a source of raw materials:

“The planet’s proximity to the sun, its low gravity, and metal-rich concentration make it the ideal source of raw materials for constructing thousands of O’Neill cylinders.”

In a previous post on Predict, he explains how to kickstart a program for harnessing space resources to fabricate these colonies.

After many years of construction, multiple rings of rotating habitats would eventually encircle the sun harnessing a vast amount of the energy output of our star approaching the configuration of a Dyson sphere.

Artist depiction of multiple rings of rotating habitats around the sun. Credits: Katie Lane (Full distribution rights reserved by Erasmo Acosta)

Finally, as a tribute to the father of free space colonies and an inspiration for a generation of space settlement advocates, I’d like to close out this post with a link to the just released trailer for the much anticipated documentary: The High Frontier, The Untold Story of Gerard K. O’Neill.

Simpler methane production on Mars

Artist’s depiction of activities at an early Mars base which could include methane production. Credits: NASA

A team of physicists at the University of California, Irvine has found a short cut for efficient propellant production on Mars. The UCI researchers have discovered a way to streamline the conventional two step Sabatier process which first electrolyzes water into hydrogen before reacting with carbon dioxide in the Martian atmosphere to create methane. Both SpaceX and Blue Origin use methane in their rocket engine designs. The novel approach simplifies fuel production by leveraging zinc as a “synthetic enzyme,” which catalyzes carbon dioxide to synthesize methane directly. The improved process will reduce the amount of ISRU equipment (and therefore weight and launch costs) needed for transport to the surface of Mars to facilitate propellent production required for the trip home. The research has only demonstrated proof of concept so follow-on studies are required to improve the TRL for flight-ready hardware.

Project MOONRISE demonstrates 3D printed regolith structures under lunar gravity conditions

Artist impression of the MOONRISE laser mounted on a lunar rover for fabrication of structures on the Moon. Credits: Laser Zentrum Hannover / 3D Printing Industry

A German company called Laser Zentrum Hannover .eV in partnership with the Technical University of Braunschweig has been working on a project called MOONRISE which aims to use laser technology to build a village on the Moon out of lunar regolith. Toward that end, the team for the first time has demonstrated the ability to 3D print structures out of simulated lunar regolith under lunar gravity conditions. The results of their experiments are described in an article in 3D Printing Industry.

The research was carried out in the Leibniz University Hannover’s Einstein-Elevator, a large-scale drop tower device in which experiments can be run under variable gravity conditions at a high repetition rate.

Initiated in 2019, Project MOONRISE is funded by the Volkswagen Foundation and is focused on improving the technology readiness level of additive manufacturing using lunar regolith as building material.

Survey of industry experts on challenges of lunar ISRU by 2040

Artist impression of ISRU activities on the Moon. Credits: NASA

What do space experts in industry and academia think will be the technical and policy challenges to overcome for a sustainable lunar outpost leveraging ISRU by 2040 to be realized? A survey using the Delphi method has just been completed to answer this question. The results were just released as a pre-proof in Acta Astronautica. Significant contributors in the fields of ISRU technologies, space architecture, power systems, and space exploration participated in the survey.

There was a group consensus that NASA’s Artemis mission returning humans to the Moon would be delayed by at least 2 years from the previous administration’s target of 2024 due to uncertainty in U.S. policy over the next few years. No surprise here. There was also agreement that ISRU processes could add significant power requirements on the order of 1 MW to a lunar base, and that photovoltaic systems were preferred over nuclear power sources because of a “…political distaste for space nuclear power systems”. Of particular note, the survey participants could not reach agreement on the impact that Covid-19 would have on space exploration.

Where should we get oxygen on the Moon?

Artist impression of activities at a Moon Base which could include oxygen production. Credits: ESA – P. Carril

Kevin Cannon of the Cannon Group at the Colorado School of Mines can help find the answer. In a recent post on his Planetary Intelligence blog, the Assistant Professor of Geology and Geological Engineering describes a trade study comparing extraction of oxygen from regolith such as Metalysis’ ESA funded study to getting O2 from ice mining at the lunar poles as favored by NASA. Nothing stands out from a cursory look at the pros and cons of each approach.

In a more data driven analysis to compare apples to apples, Cannon examines energy costs of mining oxygen and plots it against the amount of bulk material that has to be processed to produce an equal amount of O2 from different sources ranging from plain silicate regolith to various grades of water ice endmembers. The analysis even includes processing material from various types of asteroid resources. The types of ice/regolith mixtures can vary widely as described in one of Cannon’s tweets.

Artist’s impression of different types of water ice / regolith endmembers. Credits: Lena Jakaite / strike-dip.com / Colorado School of Mines

Cannon’s analysis reaches the conclusion that “At 1.5-2% water by weight, icy regolith is essentially on par with O2-from-regolith on a joule for joule basis. In other words, if you had a pile of icy regolith already sitting on the surface, it makes sense to throw it out if the grade is less than about 1.5% and extract oxygen directly from the silicate regolith instead.”

More brilliance from the mind of Kevin Cannon can be found in these posts: Want to eat like a Martian in an environmentally friendly manner?, The logistics of dining off Earth, SpaceX will need suppliers for Mars settlement, The accessibility of lunar ice. And of course, don’t forget to visit kevincannon.rocks.

ArmorHab mission architecture for Mars Colonization

ArmorHab transport habitat configured for artificial gravity. Credits: Dark Sea Industries LLC / University of New Mexico / The Mars Society

The innovative ArmorHab mission architecture was presented at the Mars Society Conference in 2016. This novel approach should be considered as part of a strategy for settlement of the Red Planet. The concept integrates several engineering solutions for habitat design to address radiation protection, life support, and transportation while leveraging in situ resource utilization to enhance crew health, safety and reduce costs.

The basic building block of the architecture is a cylindrical Mylar shell wrapped in superconductive tape providing radiation protection through emulation of a magnetosphere. This structure is encased in a protective aerogel for strength and insulation including layers of water ice to further protect the crew from micrometeorites and algae bioreactors for scrubbing carbon dioxide for life support.

ArmorHab wall structure with superconducting tape for radiation protection and algae bioreactors for life support. Credits: Dark Sea Industries LLC / University of New Mexico / The Mars Society

Leveraging Buzz Aldrin’s Mars Cycler invention, the plan starts by building out infrastructure in cislunar space including automated factories on the Moon, then expanding out to Mars with space stations, cycling habitats and connecting “trucks” to provide transport to and from the surface of each destination.

Illustration of cycler model showing six TransportHabs, three space stations and a Mars Truck. Credits: Dark Sea Industries LLC / University of New Mexico / The Mars Society

First demonstration of wireless power transmission in space

Left – Image of the Photovoltaic Radio-frequency Antenna Module (PRAM). Credits: of U.S. Naval Research Laboratory. Right: X-37B orbital test vehicle. Credits: Boeing

The first on-orbit demonstration of wireless power transmission, technology that could eventually support elements of a space solar power satellite has just been completed and published in the IEEE Journal of Microwaves. This experiment, the first flight test of a solar-to-RF Photovoltaic Radio-frequency Antenna Module (PRAM) lovingly referred to as a “sandwich module”, was performed on the U.S Airforce’s X-37 Orbital Test Vehicle, the launch of which SSP covered last May. Preliminary results have duplicated in space the expected power transmission that was tested on the ground pre-flight. Although testing is just getting started, the results show proof of concept of this prototype PRAM paving the way for the next phase of the Space Solar Power Incremental Demonstrations and Research (SSPIDR) project planned by Air Force Research Laboratory. The primary objective of SSPIDR is delivery of power to forward deployed expeditionary forces on Earth which would assure energy supply with reduced risk and lower logistical costs. The technology could eventually be used for commercial energy production.

Modular solar-to-RF panels based on the PRAM concept will enable very large radio frequency power beaming apertures to be assembled from a single panel design leading to scalability, lower mass and reduced costs.

Depiction of the PRAM functional mechanism for solar power satellites. Credits: Christopher T. Rodenbeck et al. / IEEE Journal of Microwaves

The next step in Phase 1 of the the SSPIDR project will be the world’s first space-to-ground power beaming demonstration of a solar to-RF modular panel currently planned for 2023.

SAM: Space Analog for the Moon and Mars

Exterior view of SAM. Credits: samb2.space
Interior view of greenhouse controlled environment with depiction of SIMOC temperature, humidity, and carbon dioxide level control panel. Credits: samb2.space

Located at the iconic Biosphere 2 facility in Arizona, SAM is a hi-fidelity, hermetically sealed science center about to begin cutting edge research into environmental control and life support systems (ECLSS). The facility will host researchers to perform experiments on plant physiology, regolith chemistry, food cultivation and a host of other studies in the context of a space habitat analog.

Utilizing the original Test Module which completed three closed cycles to test water and human waste recycling prior to the main Biosphere 2 facility construction, SAM will be fitted with an airlock and pressurized enclosure including quarters for research crews to stay up to two weeks at a time.

Of particular interest, SAM in partnership with National Geographic, will help validate SIMOC, an interactive closed-loop life support system simulator based on authentic NASA data. Feedback from SAM will refine the SIMOC mathematical model that balances food, air, water, agriculture and solar energy to support humans in a closed ECLSS.

SIMOC was developed though a grant by Arizona State University’s Interplanetary Initiative. Unveiled at the Mars Society 23 Annual International Convention last October (see page 87 of the Conference Abstract) the software is licensed and hosted by the National Geographic Society for integration into classrooms globally where curricula is provided for teachers to get students involved as citizen scientists to design habitats to sustain human life on the Moon and Mars.

Screen shot of SIMOC habitat interactive simulation software. Credits: Kai Staats / National Geographic Society

As stated on the SAM at B2 website:

“There is no single-run experiment that results in the ideal solution for providing breathable air, recycled water, food and waste reprocessing. Rather, we will see an unfolding of experiments, findings, and prototypes for decades to come. Much as farming evolved from the art of crop rotation to the science of genetically modified organisms, living on the Moon, Mars, and in free space will demand constant improvements in our systems as more humans move to off-world homes.”

Kai Staats, Director at SAM, was a recent guest on The Space Show where he provided a history of the creation of the facility and his role in developing SIMOC.

Ceres megasatellite space settlement

a) Artistic rendering of a megasatellite constellation of habitats with inclined mirrors for collection of sunlight – detail of individual habitats shown in b). Credits: Pekka Janhunen

Pekka Janhunen of the Finnish Meteorological Institute, Helsinki, Finland has just posted a paper on the arXiv server describing his concept for a megasatellite space settlement in orbit around Ceres and constructed from materials from this dwarf planet in the asteroid belt. Ceres is chosen because of the availability of nitrogen and water needed for life support. A space elevator is proposed as an efficient means of lifting materials off the surface.

Janhunen works out the physics and mass budgets for a collection of settlements comprising the megasatellite, each providing 1g artificial gravity and a closed-loop life support system. The assemblage is made up of a collection of self contained rotating habitats which are interconnected and could potentially grow to house billions of people with 2000 square meters of living area per person. Each habitat would include soil thick enough to enable biomes with trees and ideal weather.

SSP covered another free space settlement concept by this author last April a bit closer to home at L5 in the Earth-Moon system. Janhunen discussed this duel-dumbbell design on The Space Show in May of last year.

Directed energy propulsion technology for rapid travel to the outer solar system (and the stars)

Artist’s depiction of propulsion concept using Directed Energy. At left, Directed Energy Launch Technology Array (DELTA) beams power to laser powered electrical propulsion (LEP) spacecraft for rapid travel to the outer solar system or for laser sailing to the stars. At right, a sub-module from a close packed array of laser emitters within DELTA. Credits: Todd F. Sheerin / International Astronautical Federation

A concept for fast transit to the outer solar system and beyond has just been published by Todd F. Sheerin et al.* in Acta Astronautica. Since the article is behind a paywall, SSP has obtained permission by one of the coauthors, Professor Philip Lubin at the University of California, Santa Barbara to link to an earlier version of the paper presented at the 70th International Astronautical Congress held in Washington D.C. back in October 2019. Professor Lubin is Director of the Experimental Cosmology Laboratory at UCSB where he oversees research on several interesting directed energy projects.

The concept makes use of an Earth-based Directed Energy Launch Technology Array (DELTA) to beam laser energy to photovoltaic cells on an electric propulsion vehicle for travel within the solar system, or for photon reflection via a laser sail on gram-scale spacecraft accelerated to relativistic speeds for interstellar missions. In the former case, this method leverages existing solar electric propulsion technology which converts optical energy to propulsive jet power like what was used on NASA’s Dawn mission. An existing NASA Innovative Advanced Concepts (NIAC) program at UCSB has demonstrated proof of concept for elements of the array.

The DELTA architecture development can be terraced in progressive stages starting with small one meter arrays building up to large 10 km systems. The concept could support a range of missions, from swarms of gram-scale robots all the way up to human-rated spacecraft greater than 100 tons.

The authors believe this approach “… enables a scalable, cost effective roadmap to rapid solar system transportation for robotic and human missions alike, including robotic and human Mars-in-a-Month missions, with transit times of 30 days, as well as the first robotic relativistic interstellar flight within our lifetime.”

* Authors: Todd F. Sheerin, Elaine Petro, Kelley Winters, Paulo Lozano, Philip Lubin