The Guest speaker at the May monthly meeting of Keighley Astronomical Society was Dr Martin Braddock from the ‘Sherwood Observatory’.
Dr Braddock explained that his work has been in the medical field particularly looking at how to improve the conditions so that damaged human tissue particularly the skin can heal itself. This presentation would look at the planed future missions to the Moon and Mars and how that would be done with regard to the health and well being of those taking park in the missions.
So when and where are we going?
The Artemis program is a robotic and human Moon exploration program led by the United States’ National Aeronautics and Space Administration (NASA) along with three partner agencies—the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA). The Artemis program is intended to re establish a human presence on the Moon for the first time since the Apollo 17 mission in 1972. The main parts of the program are the Space Launch System (SLS), the Orion spacecraft, the Lunar Gateway space station, and the commercial Human Landing Systems. The program’s long-term goal is to establish a permanent base on the Moon to facilitate the feasibility of human missions to Mars.
Under Artemis’ umbrella are several components. First is the Lunar Orbital Platform-Gateway, a station around the moon that would extend humanity’s presence in space and provide a platform for scientific experiments and jaunts to the lunar surface.
The Gateway would be carried into lunar orbit by the agency’s SLS rocket, a gigantic new rocket NASA is developing. Four-person crews would access the station using the Orion deep-space capsule and remain for 30 to 90 day stints.
Part of the push towards the moon includes an enlarged role for private aerospace firms, which are intended to develop hardware and potentially kick-start a lunar economy. NASA has awarded $45.5 million to 11 U.S. companies, including Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin, to develop landers that can take astronauts to the moon’s surface. SpaceX was selected to provide the Artemis 3 crew lander based on that company’s huge Starship vehicle.
For the initial Artemis moon missions, the selected astronauts will likely fly to the moon’s south pole. This area has great potential, as it is believed to be home to the highest abundance of water ice. If we can extract this water, it could be used to sustain human exploration farther into space, whether that’s as a human hydration source, rocket fuel resource, or cooling system for equipment.
Shackleton crater is a huge 12-mile (19-kilometer) depression in the moon’s surface and a feature definitely worth visiting. With a permanent shadow cast in the dips of the crater, the low temperatures make it a promising location for ice to form.
In fact, these permanently lightless areas maintain some of the coldest temperatures in the entire solar system. Although it’s possible that water can be found even on the moon’s lit surfaces, an area likely to have the highest abundance of water is the best spot to start looking for further natural resources.
The gateway to Mars
While Artemis 1 will serve as an important test of much of the technology needed for prolonged space travel, one important aspect of NASA’s crewed moon plans remains unestablished — the Gateway space station.
Gateway will be the first space station placed into orbit around the moon. Equipped with docking points for various spacecraft, a module called the Habitation and Logistics Outpost (HALO) — serving as the station’s living and work areas — and scientific equipment, Gateway will add sustainability to operations on the moon and for crewed deep-space journeys, NASA officials say. It will also allow refuelling for extended trips into space.
But, even before such journeys are underway, Gateway — for which key components are expected to launch no sooner than November 2024 — will help NASA and other space agencies investigate the effect of long-term deep space missions on the human body.
Gateway will also play an important role in the delivery of materials to the moon that will help develop infrastructure on the lunar surface.
This infrastructure will eventually include a transportation system that can deliver large payloads from Earth to Mars via the moon, if all goes according to plan. This capability, in turn, will lead to the development of power systems on the Martian surface that could enable long stays on the Red Planet for humans.
These are not short-term goals. NASA currently estimates that humans won’t be ready to set foot on Mars until at least the late 2030s or the early 2040s. It’s clear, however, that Artemis 1 represents an important first step on the long road to Mars.
NASA has awarded high-tech construction company ICON a nearly $60 million contract to develop Olympus, a 3D-printing system specifically designed for building on the moon and Mars.
The cost of sending all the construction materials needed to build a significant moon base from Earth to the moon would be astronomical, so NASA’s plans for building on the moon depend on using as many local resources as possible.
Now, NASA has awarded ICON, a Texas-based company specializing in advanced construction tech, a $57.2 million contract to develop Olympus, a 3D-printing system that could be used for building on the moon, and Mars, using local materials.
“[Olympus] will allow us to … build all the elements of infrastructure necessary for a lunar outpost and ultimately a moon base,” ICON CEO Jason Ballard. “This is launch and landing pads, roadways, habitats, you name it — all the things we need on the moon.”
While the 3D printers ICON uses to construct houses on Earth utilize a water-based concrete “ink,” Olympus will take a different approach.
“We’re using a high-powered laser to actually transform moon dust into building material,” said Ballard, noting that his company has also experimented with microwaves, infrared light, and melting for off-world construction.
This isn’t the first collaboration between NASA and ICON.
The agency has been helping fund the company’s plans for off world construction since 2020, and in 2021, ICON unveiled Mars Dune Alpha, a 3D-printed facility at NASA’s Johnson Space Centre that will be used for a year-long simulated Mars Mission starting in later this year.
The new NASA contract runs through 2028, and during it, ICON will continue developing the Olympus system using actual samples of lunar regolith, brought back during NASA’s Apollo missions, as well as simulated moon dust.
ICON will also bring its hardware and software into space during a flight designed to simulate lunar gravity. Ballard said that the company hopes to be building on the moon by 2026, with the first structure likely to be a launch and landing pad.
“The final deliverable of this contract will be humanity’s first construction on another world,” he said, “and that is going to be a pretty special achievement.”
Dr Braddock pointed out that the big factor in this push for the Moon and Mars would be the risk factor to those astronauts. The risk of death, injury and sickness. Including metal health.
Living space and on other worlds will be confined and design and construction of habitats will be very important. That design will have to be as safe as possible to reduce risk of injury and to promote a sense of well being.
It will be inevitable however those injuries will occur and procedures have to be in place to tend to those injuries and return the person or persons in question back to Earth.
The further they are away they are from Earth the less likely they are of ensuring a full recovery or that they will survive serious injuries.
Dr Braddock outlined how with others they had put together a crowd-funding package to finance a research project involving several interested young potential scientists. On how could you safely operate a Martian colony for 50 years or so. There work was published in several journals including ‘Astronomy Ireland’.
Landing Humans on Mars
Building a settlement on Mars will require a lot more work than creating a settlement on the Moon. The journey to Mars alone is fraught with danger due to the great distance between the Earth and Mars (at its closest point Mars is a mere 55,000,000 km away), and as such the total journey time could take between 150-300 days depending on the distance between the planets at the time of launch and the rockets, aka the amount of fuel, being used.
Add to that the difficulty of launching and transporting all the materials needed, the effects on human physiology and psychology during the long, confined, radiation-drenched journey, and the technology required for landing on Mars and taking off again, moving to Mars is no easy option.
Building a Mars Settlement
Moving and setting up a base on Mars is not so much “to boldly go”, but “to boldly stay”. We can get there but how can we survive sustainably?
To build a habitat on another world is no easy feat; for Mars, it requires a number of considerations such as how building materials will respond to the dusty, low air pressure environment, the extreme temperatures, outward forces from pressurised habitats, radiation damage, and the 38% gravity of that of the Earth.
Due to the time taken to travel between Mars and the Earth (not to mention the cost), a habitat on Mars will need to be self-sustainable for future Martians having to provide oxygen for them to breathe, water to drink, food to eat, protection from the harsh radiation environment, light and power, and stable comfortable temperatures.
One design is for stereotypical inflatable domes like we use in extreme environments on the Earth. These are lightweight and would be relatively easy to erect on the surface, however, they would need protection. Local materials such as regolith and soil could be used to make concrete and to cover the inflatable habitats providing an additional layer of defence against radiation and micrometeorite strikes.
There are a number of geological landforms such as impact craters and also ancient lava tubes within which habitats could be erected. These natural cavern systems provide a structure within which habitats can be built and easily sealed, the rock provides protection from the harsh surface environment, and they are commonly interconnected allowing for the habitat to grow.
Many studies are being conducted into the logistics of how human life might be sustained on Mars; such as the MOXIE experiment onboard NASA’s Perseverance rover, which in 2021 managed to create oxygen from the Martian carbon-dioxide atmosphere.
Terraforming – making Mars habitable
When humans finally make it to Mars we will live in a similar manner to how we do in Antarctica in enclosed habitats maintaining an Earth-like environment inside. But is this a sustainable future for our species?
It might take millennia to achieve, but instead of recreating the Earth in miniature where the failure of a single vital piece of technology could put lives at risk and where resources are finite, we could transform Mars into another Earth and bring it sustainably back to life – a process called terraforming.
Terraforming Mars would entail three major interlaced changes: building up the atmosphere by inducing a stronger greenhouse effect and global warming, keeping the planet warm enough to allow liquid water to remain stable on its surface which would support vegetation growth, and protecting the new atmosphere from being lost to outer space. Most of the legwork would be done by life itself; we would just warm the planet up, throw in some seeds and bugs and allow life to take over.
Looking to the future?
Although tantalisingly close, Mars isn’t the only world we plan to explore looking for life.
We will head back to the gas giants of Saturn and Jupiter to investigate features on their moons, such as the secret ocean hiding beneath the icy shell of Europa, the gargantuan jets emanating from Enceladus and the liquid hydrocarbon lakes on Titan. We are also launching telescopes and satellites to hunt for habitable exoplanets.
Yet our greatest challenge to overcome in this astrobiological treasure hunt is distance. We cannot change the expanse of space we need to cross to reach even the nearest star systems and their potentially habitable planets (for example Alpha Centauri is a ‘mere’ 25-trillion-miles away) but at our current level of technology, it would take nearly 74,000 years to get to them.
As such over the coming century there will be a huge push to design and refine technologies to propel us further and faster (but safely) into the cosmos. The idea that we will find alien life, travel to and perhaps even inhabit other planets and other parts of our galaxy has become part of an image of our destiny, even a measure of our future success.
How to 3D print a habitat on Mars
Inspired by centuries-old construction techniques, LavaHive is a Mars colony built using the planet’s own sand and dust. Such in-situ resource utilization makes it possible to make significant savings on the mass and cost of a mission to the Red Planet. Both NASA and ESA have demonstrated an interest in this technique as a way of achieving their ambition.
Additive manufacturing has captured both commercial and public interest in recent years. Often referred to as 3D printing, a slew of disruptive commercial applications have already been demonstrated and many more foreseen. Now, teams around the world have been inspired to design a 3D-printed Mars habitat for a NASA competition.
As a process, 3D printing of sorts has existed since antiquity, when grand structures were built additively, layer by layer. It is only recently that we have combined the technique with robotics and computer control, enabling 3D printing of objects of nearly any shape using a diverse range of materials, from metals to plastics and even ceramics. Certain complex geometries, impossible to make using traditional manufacturing techniques, are also made possible using 3D printing methodologies.
The advantages are numerous – logistical requirements, materials usage and manufacturing time are all reduced. And product applications are wide in range, from low-weight bespoke jet engine parts to the fabrication of complete concrete houses.
The mission-enabling potential of this technology is not lost on the space agencies. In 2013, ESA commissioned a study under its General Studies Programme to investigate how 3D print methodologies could be used to fabricate a dome-like structure for a lunar facility, protecting astronauts from the harsh radiation and micrometeorite impacts on the Moon. By using local resources to fabricate important mission elements as opposed to shipping them from Earth, an application known as in-situ resource utilization (ISRU), it’s possible to make significant savings on the mass and cost of the mission.
NASA has also turned its attention to the possibilities of using 3D printing on space missions. In March 2015, it announced the 3D Printed Habitat Challenge, which is open to entrants from across the globe. Teams put forward an architectural concept for a 3D-printed Mars base, with the aim of fostering the development of technologies necessary to additively manufacture a habitat using ISRU and the recycling of spacecraft materials. It’s a so-called NASA Centennial Challenge – an incentive prize offered to generate disruptive solutions to problems of interest to NASA. With this approach, NASA aims to engage with non-traditional sources including the global ‘maker’ community – enthusiasts and entrepreneurs from the general public who have championed 3D printing technology and its applications.
Inspired by the previous study carried out by ESA on lunar 3D printing, a team consisting of members of the European Astronaut Centre and Liquifer Systems Group of Austria have joined forces to develop a concept for this Centennial Challenge. The team has been selected as one of the top 30 entries out of more than 160 entrants, and asked to present its concept at the World Maker Faire in New York in September 2015.
The concept, named LavaHive, shows the unique potential that additive manufacturing technologies have for future exploration missions. In the proposal, the feedstock material used as raw material for the 3D printing process is Martian ‘regolith’, a catch-all term for the loose sand and dust that’s readily available on the surface of Mars. By using this local material to produce structures and shelters, significant mass savings can be realized, leading to a reduced logistical supply burden from Earth.
The LavaHive concept is a novel hybrid approach. It consists of an inflatable central habitat with 3D-printed reinforcement walls, and a series of interconnected sub-habitats made from sintered and molten Martian regolith, plus recycled and repurposed spacecraft parts. Sintering involves using heat and/or pressure to fuse particles, and its feasibility using regolith has been demonstrated on Earth via numerous projects.
LavaHive is a modular design for an initial mission of four crew, with the ability to expand or adapt to changing mission requirements. In its initial state, a hybrid inflatable-3D printed main habitat is connected via a central corridor to three or more sub-habitats. The main habitat houses crew living areas and is connected via 3D-printed passageways with the sub-habitats. These house a laboratory, greenhouse, garage airlock and other required working areas.
There are a number of reasons to adopt a hybrid approach of purely 3D-printed sub-habitats connected to a central inflatable habitat brought from Earth. The central inflatable habitat offers a number of advantages, such as assured structural integrity as well as the ability to house essential functionality such as the Environmental Control and Life Support System (ECLSS) modules and environmental sealing of the habitat.
The back-shell from the Entry, Descent and Landing (EDL) system will be recycled as the roof of this central habitat. This will be used to reinforce and protect the inflatable structure that deploys underneath from hazards such as micrometeorites and radiation.
The architectural inspiration came from two examples of ancient ‘habitats’ – the Clochan beehive huts of the Irish monastic sites and the traditional South Italian Trulli homes. These are domed houses with prehistoric origins, built using the abundant stone materials from the surrounding land – a true example of ancient ISRU on Earth. In the Trulli, a plaster made of reddish clay soil and pieces of straw mixed with slaked lime was used to render the interiors of these houses hygienic and clean, similar to LavaHive’s proposed method of sealing. For the ancients, the final result was an earthquake-proof construction that, thanks to the thermal inertia of the thick walls, provided a cool environment in hot weather and kept warm in winter.
Building the habitat
On arrival in the Martian vicinity, the mission delivery vehicle will detach the EDL system and send it on a trajectory towards the surface. The EDL will jettison its heat shield and then deliver two surface rovers and the central inflatable section of the habitat to Mars.
The two autonomous rovers included in this payload will be used for the 3D construction process, with one used to sinter and the other used to melt regolith. When the entry capsule comes to rest on site, the inflatable habitat will deploy with the EDL back-shell still attached on top. This will offer additional protection to this critical central node of the habitat.
The two autonomous rovers will then begin preparing of the area for the construction of the 3D-printed elements. The rovers will identify and collect the local fine regolith sources available from aeolian, or wind-created, deposits within craters and beds and transport them to the habitat site. First, the sintering-capable rover of the pair will begin producing foundations for the smaller habitat sections, with the foundation then completed by the lava-forming robot.
The rovers will then work in tandem to begin the fabrication of the habitat sections and connecting corridors using in-situ regolith resources. When one cast layer has cooled, the rover begins layering more regolith sand, and a new channel is sintered on top. This process is repeated until the dome is complete. Once arrived, astronauts will perform final construction operations tele-robotically from Mars orbit or manually from the surface. They’ll install mission elements brought from orbit, such as airlocks and safety doors. Once structurally complete, the sub-habitats will be hermetically sealed with epoxy coating on the inside surfaces of the sub-habitats, sprayed on by a rover. This epoxy will form a sealed environment with the main habitat.
A key element of the LavaHive habitat concept is to make use of components that are usually discarded, such as the EDL back-shell to protect the inflatable habitat section. In addition, materials like nylon, polyester, Kevlar, low density polyethylene, titanium, carbon fibre composites, polyimide and PTFE, and parts such as fuel tanks and wiring will be taken from the EDL system post-landing. They’ll be reused inside the habitat: for example as storage for water or gas. The recycling of polymers opens up novel reuse applications within the interior of the habitat. Using the waste polymers as feedstock for existing plastic additive manufacturing techniques, it is possible to produce a variety of mission-specific tools and fittings. This recycling approach increases mission flexibility, allowing ad-hoc production of parts as the need arises and is paramount for a logistically self-sustaining mission to Mars.
Why we love lava
Printing using lava may seem incredible, but is in fact an elegant and simple approach. The lava-casting manufacturing process is inspired by naturally occurring lava flows and its feasibility has been confirmed by small-scale demonstration projects here on Earth.
The aeolian dunes and beds from which regolith could be collected are well understood in terms of their particle size distributions, which is an important consideration for understanding the dynamics of any sintering process. The regolith will be melted inside a furnace on the rover, and then cast in channels made from sintered regolith.
This lava 3D printing approach has several advantages. First, as a building material, it is stronger than thermally induced sintered material. Since the four-man astronaut team would be expected to work safely within these 3D-printed structures, confidence in the structural elements supporting the rooms is crucial. Second, we can expect basaltic lava, once cooled, to have a much higher density than any sintered material. This would have considerable benefits for radiation shielding in the surface environment. The permeability of basalt stone is also superior to that of a sintered process, which is often porous, and this is an important consideration for forming a hermetic environmental seal.
While it may seem difficult, heating and control of the lava itself is relatively easy to achieve. Lava is highly viscous yet can readily flow long distances before cooling. An analogue test habitat on Earth is also easily achievable, and lessons learned during construction of terrestrial Mars analogue sites would be transferable to the Martian environment.
As a concept, the LavaHive approach is a great example of how ISRU and 3D printing can be combined to enable exploration missions on the Martian surface. Many of the concepts, like the sintering of regolith, are already being proposed for lunar exploration. The techniques would need to be further developed and tested here on Earth, but this is also a latter part of the NASA Centennial Challenge.
The additive manufacturing movement has shown that changing the way you approach fabrication can open up new possibilities. That future explorers would end up employing the construction processes used by our ancient forebears for the first Martian habitat is fitting for the development of our own first settlements off Earth.
What does the future hold?
Astronauts are growing the beginnings of new organs on board the International Space Station.
The experiment is an attempt to grow human tissue by sending adult human stem cells into space, and allowing them to grow in space.
Eventually, it is hoped, the stem cells will develop into bone, cartilage and other organs. If that is successful, the discoveries could be used to try and grow organs for transplant, the scientists involved say.
The experiment uses “weightlessness as a tool”, according to Cara Thiel, one of the two researchers from the University of Zurich who are conducting the research. The lack of gravity on board the International Space Station will be used to encourage the stem cells to grow into tissue in three dimensions, rather than the single-layer structures that form on Earth.
It is being conducted by the astronauts on board the International Space Station using a “mobile mini-laboratory”.
On Earth, tissue grows in “monolayer” cultures: generating flat, 2D tissue. But investigations both in space and Earth suggest that in microgravity, “cells exhibit spatially unrestricted growth and assemble into complex 3D aggregates”, said Oliver Ullrich, who is also leading the research.
Previous research has involved simulated ad real experiments, mostly using tumour cells, and placing real human stem cells into microgravity simulators. But for the next stage of the research “there is no alternative to the ISS”, he says, because 3D tissue formation of this kind requires several days or even weeks in microgravity.
To see successful formation of ”organoids” – smaller, more simple versions of organs – inside the test tubes. “The test tubes were launched with stem cells and are expected to return to Earth with organ-like tissue structures inside,” said Professor Ullrich.
Scientists are still not sure why the conditions of the International Space Station lead to the assembly of complex 3D tissue structures. Professor Ullrich and other scientists are still continuing to research how the gravitational force and the “molecular machinery in the cell” interact to create new and different kinds of tissue on Earth and in space.
Dr Braddock’s presentation ended with a question and answer session.