Research & Development

An all new SAM Team page is now active!

This year will see a shift in the SAM team. While in a corporate environment it is expected that the team and total productivity always grow, in an academic environment teams fluctuate—semester to semester, research project to research project, year to year.

At the start of the SAM project in January 2021 all team members were volunteers, including Kai and Trent. With a dozen volunteers that spring, the team then shrunk to just a few in the fall, growing steadily again through 2023. Volunteers provided what time they had. Some became paid staff. Students graduated and moved to jobs in their field.

The fall of 2024 was a transition with the realization that the SAM project had matured, now requiring more than pairs of willing hands and a willingness to learn new skills—SAM needs focused skill-sets and experience to bring specific ideas to form. This resulted in our first ever job posting and a new hire.

Griffin Hentzen comes to us from Purdue where he recently graduate with a BSc in Aerospace Engineering from Purdue University. He has interned at Sierra Space for two semesters, with a focus in carbon dioxide scrubber systems. He will be focusing this year on the design and fabrication our new CO2 scrubber at SAM, working closely with Dr. James Knox (also a part of the SAM team) and Director of Research lead Kai Staats, while lending a hand in myriad tasks as presented.

Welcome Griffin!

Masters student Amy Sawyer, working under Arizona State University professor Changbin Chen, has completed a one month study of four species of tomatoes, grown in the next-gen hydroponics system at SAM, a Space Analog for the Moon & Mars located at the University of Arizona Biosphere 2.

There are times when a narrative is a necessary companion to a photo. There are times when a photo is worth a thousand words. And then there are times when you scratch your head and wonder …

As part of the overall design strategy for SAM’s life support system architecture, the SAM team is looking at developing a hybrid solution that incorporates both physicochemical (mechanical + chemical) elements along side bioregenerative (plant-based) elements. The team is working on developing all these elements simultaneously to ensure they are designed to interface effectively. Luna and Sean have been hard at work focused on the bioregenerative side of this critical part of the SAM architecture.

On April 22-25 of this year, the team met with a research group from the Technical University of Munich (TUM) with a research focus on the use of algae cultivation for the support human space travel. The team consisted of Gisela Detrell, Lina Salman, and Sergio Santaeufemia Sánchez. Through the TUM team’s hard work, they secured the support of their university to meet with the SAM team in person and explore how our research could overlap to be mutually beneficial. As part of this discussion, the TUM team flew out to Tucson to see SAM and Biosphere 2 in person.

The workshop occurred over 4 days, providing ample time to share what we were working on and to see how we overlap each other.

During day 1 of our workshop, Sean took the TUM team on a briefn tour of the U of A main campus and had the opportunity to meet with Dr. Joel Cuello who also researches in the field of the application of algae to supporting human space travel. The discussion lead to some exciting insights and possibilities for future collaboration. The second day the team was hosted at the B2 campus and the TUM team shared about the wide variety of research projects they are working on including photobioreactor (PBR) design and modeling, student and public workshops focused on human space travel, and how SAM could incorporate at PBR into its design. A photobioreactor is a system that provides the light an nutrients needed to cultivate an algal culture.

Day 3 of the workshop was tour day where the team was taken on a private tour of the Biosphere 2 facility and SAM. This was extra special for the TUM team as they teach about the history of Biosphere 2 in some of their classes. With this being the first opportunity any of them had to visit in person, they got the full experience and will now be able to speak from personal experience in their lectures! The SAM tour focused primarily on the habitat facility as the Mars Yard wall build was occurring simultaneously. Dr. Cuello also joined for the tour of SAM and was excited to see the facility in person for the first time as well. The fourth and final day of the algae workshop was an opportunity to discuss how we move forward as a team and the actions we can take to explore how we can continue to work together moving into the future. We are excited to continue to explore with and learn from the TUM team especially to eventually see the integration of a photobioreactor within the SAM habitat!

Overall, the visit to Tucson was a very productive discussion and we are all excited about the possibilities the future holds for our teams to continue to work together. Luna and Sean will be headed to Germany to see the the TUM facilities in December and are excited to continue exploring synergistic working possibilities for our teams!

Mars yard at SAM model by Bryan Versteeg | spacehabs.com

In 2023 Kai invited Dr. Jim Bell to visit SAM. Dr. Bell is a world renowned planetary geologist at Arizona State University, School of Earth and Space Exploration, and designer of the ‘Mastcam’ cameras for the Mars rovers Curiosity and Perseverance. They reviewed the then small Mars yard “sand box” filled with crushed basalt, and discussed the ultimate expansion to a 2600 sq-ft facility complete with 10-12 foot high crater walls.

Together they considered three possibilities:

a) Take a single volcanic or impact crater on Mars and shrink it down to something that would fit within 2600 sq-ft. The challenge would be that we’d lose the detail of the features by the very function of miniaturization; or

b) Take a life-size feature such as a cliff band or gully bottom on Mars and recreate it, centimeter for centimeter adjacent to SAM. While this would give visiting crew members a very realistic EVA experience, the shelf-life for our Mars yard would be limited to the relatively narrow set of geologic features in a few hundred square meters; or

c) Build an amalgamation of features taken from various sites on Mars. This final approach results is a bit of a Frankenstein monster but is far more interesting, has a greater shelf-life, and can be modified in the future without geologic ramification.

APRIL 20, 2024
d) With the transition from an intended rebar, lath, and concrete construction medium to carved foam and shotcrete, it became possible to fabricate a realistic assembly of diverse features on Mars in the confines of a single space, and in so doing, build a world in which the represented geological layers tell a nearly complete story of millions of years of construction and erosion. Learn more …

In preparation for the arrival of Red Hen Industries and their Hollywood set construction crews, Kai once again reached out to renowned space architecture visionary Bryan Versteeg (top image) to generate a rough 3D model as a means to visualize the initial parameters of this massive undertaking.

In parallel, ASU School of Earth and Space Exploration undergraduate Tasha Coelho assembled a document that explores the varied types of features that might be represented in the SAM Mars yard geology, building on the initial photographs captured by Matthias Beach in the fall of 2023 with her own deep dive into the NASA and ASU image archives.

The features considered include: anthropogenic features, concretions and buried pebbles, conglomerates, gullies and talus slopes horizontal striations and outcrops, linear color variations, mud cracks, recurring slope lineae ripples, and veins and ventricals.

More than 100 images from the Curiosity Mars rover were studied, two dozen printed and laminated as initial guides for the Red Hen crew.

Concretions

• Clumps of minerals formed when water soaked the rock long ago
• Resistant to erosion
• Some are close to being fully revealed
• Example: Martian Blueberries (Hematite, an iron mineral). These are also found in Utah’s petrified sand dunes. They become superficial (meaning, separate from the stone in which they formed) as surrounding sandstone/mudstone erodes away. These were discovered by Opportunity the same day it landed.

Conglomerates

• Rounded pebbles bound together with varying degrees of round
• Nearby loose pebbles that have dropped out of the conglomerate
• Evidence for fast flowing water; needed to mobilize and round heavier rocks

Horizontal striations

• Buried sand dunes
• Fine grain
• Cross-bedding indicating different flows of water OR whole rock unit moved
• Horizontal Striations
• Fracturing

Veins

• Fluid-rock interactions
• Water carrying minerals and filling cracks in rocks
• More resistant to erosion compared to surrounding rock
• Dark base colors with light features (calcium sulfate aka gypsum}

Ventifacts

• Wind carved rocks
• Wind blown grains erode and smooth surfaces, similar to a sand blaster
• Resulting rock can show prevailing wind directions (learn more)

Recurring Slope Lineae

• From orbit these features appear to be meters wide and kilometers long; might also be seen on smaller scales
• Different theories for formation:
  – CO2 sublimation
  – Seasonal heating melting sub-surface briny water
  – Hydrated clays
  – Dry landslides

Anthropogenic features

• From rovers/humans attempting to learn what lies beneath the surface
• Educational opportunity
• Reveals unoxidized layer

Mud Cracks

• Floor features, or on top of flat rocks

Subsurface Water / CO₂ Ice

• Newly revealed subsurface ice imaged by Phoenix and HiRISE
• Have only been observed on the ground, not on vertical outcrops (need to verify)

Gullies + Talus slopes
These are not applicable to the size and scale of the SAM Mars yard.

Water (or CO₂) ice in cold traps
These can only be imaged from orbit, as with Korolev crater.

Written by Sean Gellenbeck, PhD

Initiated in mid January, the new, experimental hydroponics rack system was set in motion by SAM team members Sean Gellenbeck and Luna Powell. This upgrade is designed to be more effective and efficient in plant production, with intent to be fully computer monitored, controlled, and automated in the final design.

This single rack solution is a prototype built for use by (Hey! Is that? Could it be James Burk, Executive Director of the Mars Society helping carry in a shipment of new raceways!?)

To avoid these challenges, the redesigned system uses a different method called Nutrient Film Technique, or NFT. In NFT, a thin film of the nutrient solution is run through enclosed channels containing the plant root zones. With the roots exposed to the nutrient solution the plant can take up the nutrients and water they need. And the enclosed channels work to prevent the roots from drying out. This has the added benefit of reducing algae growth as the nutrient solution is now no longer exposed to light. As compared to Ebb and Flood the NFT design, less water is moved through the system at any one time. This results in a smaller pump and less complex structure to support the weight of the water above.

To create the new system, Sean and Luna made use of the metal support structure from the previous design. The flood trays were removed and replaced with 4 NFT channels running in parallel (side by side). The PVC channels are a standard within the hydroponics industry and are used in commercial applications. The channels were cut to size and sealed to prevent leaks onto other components. As with the original design, there are three levels in the NFT setup and the nutrient solution flows from one level to the next by gravity. However, where the previous design moved water simultaneously to all three levels, this new design carries water to the highest tray only, with gravity bringing the water to the lower two. In total, the system has 4 NFT channels flowing in parallel that connect to another set of channels on the second shelf (in series), followed by a third level of channels. The nutrient solution is pumped to the top set of channels and is split across all four channels before flowing from one level to the next. Finally, the draining solution returns to the main nutrient tank which is sized to reduce the need for crew interaction and allows for future development and system expansion.

In total, the new SAM NFT hydroponics rack has space for 78 plants. Thanks to our Jason at Biosphere 2, our team was able to quickly prepare the system with 4 species of lettuce, kale, collared greens, and a variety of herbs for the Imagination 1 crew to use during their mission.

After the Imagination 1 mission, development of the SAM hydroponics system will continue with refining the current design, duplicating it across four racks, and eventually building an automated control system to remove the need for manual crew intervention for pH and EC levels (electrical conductivity to measure of the nutrient level in solution). While much larger systems will be a part of the SAM ECLSS in the future, we expect to maintain this stand as a resource for crew experiments and education.