Construction

Heating and cooling the SAM Test Module (greenhouse) is paramount to the success of plant biology and food cultivar studies. Maintaining a relatively constant, controlled temperature and humidity is not easy in the context of the drastic changes in weather and conditions of the Arizona desert.

When the Test Module was first built, a separate room was required to produce hot or cold water which when pumped through a heat exchanger suspended from the interior space frame provided warm or cool air. That unit weighed a few thousand pounds and was removed piece by piece in the first few weeks of SAM effort, February 2021.

That system consumed massive amounts of electricity, likely more than 100 amps at full draw. The modern replacement, a mini-split heat pump, is far more energy efficient at just 15 amps maximum draw per condenser. What’s more, the interior air handler (sometimes referred to as the “head”) is not unlike that which could be used in an isolated, off-world habitat for it does not exchange air inside to out, rather, it recirculates air entirely internal to the controlled environment. Only the pressurized gas that exchanges the thermal energy from the condenser to the air handler moves through the wall, and in this case through a manifold that maintains the hermetic seal.

As the condenser at SAM does use a convective thermal exchange process (fan), it would not work as such on Mars for the atmosphere is too thin to conduct the heat away from the external unit. Instead, the condenser would pass the pressurized gas through a radiator likely composed of hair-like aluminum or copper filaments for maximum surface area and passive radiant thermal exchange.

The first unit was installed on June 26, 2021. This was operational for the 5-person, 4-hour test run. The second unit was installed on December 16, 2021 by the same team from AirQuest, based in Tucson, Arizona. Owner and president Aaron worked with Kai Staats for a few months prior to the first installation to calculate the required cooling and best placement of the units. As the software provided by the mini-split manufacturers does not anticipate an all glass construction at 24 feet tall, the upper reaches coated with a silicone elastomeric, a good bit of intuition and experience dictated the final design. Kai and Aaron co-designed the manifold which was then fabricated by Kai Staats and Heracio of the AirQuest team. The final product is air tight and highly efficient.

The SAM lung was designed as a prototype, something to perform a few seasons, not much more. As such, it was not sealed from the rain which over time resulted in substantial rust to the interior surface of the upper shell.

Starting in the spring of 2021 Trent Tresch scraped and sanded the loose paint. In December Kai returned to this effort, preparing the surface for primer. Volunteer Colleen Cooley and Kai Staats applied a coat of direct-to-rust primer, which both stabilizes the rust and prepares the surface for the final, enamel top coat.

Mixing, pouring, and finishing concrete is no small undertaking. While it can be done bag by bag, shovel by shovel for small jobs, the critical nature of a uniform density, physical and chemical consistency demands proper mixing and delivery by a professional concrete company and finish by the experts.

Daniel, Ricardo, and Fernando are experts in their field. They estimated the concrete delivery to within a half wheel barrow and were able to cut and position the sauna tubes for the concrete footings for the shipping containers to a level of perfection. Next, we prepare the shipping containers and west side of the Test Module for extension of the pressure vessel and in January place the containers as the foundation for the new Crew Quarters at SAM.

With the second phase of construction of SAM we are quickly transitioning from refurbish to new construction (which is far more enjoyable). In the spring of 2021 we poured a new concrete slab between the Test Module and its lung to the south in order to provide a foundation for the new mini-split A/C units, and to reduce the amount of debris and dirt that got kicked up when working in that area. The result was clear, we needed to go ahead and pour a slab around the east and west sides of the Test Module when we moved to pour the concrete footings for the 20 and 40 foot shipping containers, our soon-to-be crew quarters.

Daniel, Ricard, and Fernando are a unique team. Highly skilled, extremely knowledgeable, and absolutely a joy to work with (as well as constant comic relief!, they were able to prepare the site from gravel and dirt to line and laser level in two mornings. Kai Staats assisted with validation of the critical measurements and sketches for the precise location of this exciting addition to SAM.

Next week, the concrete will be poured!

The lower lung extension of the Test Module pressure vessel had been left open for some thirty years. Every critter known to the Senoran desert had made a home of the dark, cool space below the steel pan and flexible EPDM membrane. It was, in scientific terms, disgusting. Our first effort to clean this space was conducted in the spring of 2021 with respirator, goggles, gloves, and sprayer with a bleach-water solution to stabilize the waste and debris.

Trent and Kai inflated the lung and then attached the stilts to enable safe work beneath. Kai power-washed the underside of the pan and membrane twice. Kai and Trent then removed the loose paint with scrapers and orbital sanders, scrubbed with water and brush, and wet-mopped. The difference was night to day.

While we have experimented with latex paints in the Test Module, it became clear that water-based paints simply do not offer the needed protection for metal surfaces against further rust and corrosion. We therefore applied a Rust-O-Leum product designed to secure bare metal and rusted surfaces, followed by an oil-based enamel. The result is a highly durable, easy to clean surface that will give the lower lung another decade of function with minimal maintenance. The enamel paint will have six months to cure, more than ample to stabilize the VOCs.

Thank you volunteer Colleen Cooley for returning to SAM and lending a hand in this effort.

We have received shipment of our second shipping container, this a hi-cube, non-insulated 20 foot unit that will serve as the corridor between the Test Module and the 40 foot crew quarters. We have also detected and marked all buried gas and electrical lines in advance of the new concrete footings that will secure the shipping containers.

With the effort to remove the five, small greenhouse structures west of the Test Module and large greenhouse completed by Laura Blystone and her team, Kai, Trent, and Sean set to cleaning after a summer of intense wind and rain that brought down most of the remaining roof panels from the original, thirty years old structure.

We recycled the plywood removed from the west wall of the large greenhouse structure, standing six sheets vertically against the south wall of the large greenhouse, what will be the 6400 square-foot indoor Mars yard. In review of several photos taken by various Mars rovers, we selected an initial paint color to represent the martian sky and applied it to the plywood following a coat of primer.

Terry moved six tractor loads of crushed basalt against the plywood to form a miniature martian landscape. With this in place, we have a diorama with which we can explore a color palette for the future, sculpted concrete, scaled crater that will cover the entire length and width of this building.

With the start of our second phase of development of SAM, we decided it would be ideal to have a home-base of operations beyond our campus apartment and the shipping container adjacent to the Test Module, a space for SAM planning, systems design, and development of components vital to first-team missions and operations.

In June Biosphere 2 Deputy Director John Adams allocated one of the three buildings in the lower B2 parking lot for the SAM Operations Center. This building had been used as storage for B2 cleaning supplies, linens, dish ware, and office supplies; and the building we would move these items into was equally full with pre-COVID K-12 staff offices, supplies, and more storage.

Early in October Trent and Kai dove into sorting, moving, and cleaning both buildings to establish the SAM operations center and to help the B2 staff regain organization and efficiency for daily operations as the Biosphere 2 ramped back up toward a pre-COVID level of daily and conference center visitors.

With this initial effort concluded we have the foundation of an operations center complete with a kitchen, library, mission control center, conference room, and workshop. Next we will determine the desired layout of the operations center and engage in re-construction in parallel to the vital effort of expanding the Test Module pressure vessel with the crew quarters.

It is our pleasure to bring to a close Phase I development and construction of a Space Analog for the Moon and Mars (SAM) at Biosphere 2. This past six months of research, design, engineering, and hands-on construction has been a tremendous labor of passion by Kai Staats, Trent Tresch, Biosphere 2 Deputy Director John Adams, Tim Mcmullen and Terry Murchek of Biosphere 2’s maintenance staff, intern Natasha Loving, and our volunteers Cameron Smith, KC Shasteen and Michael Blum, Linnaea Groh and Atila Meszaros, Robert David and Angus Gluck, Colleen Cooley, Trenton Kenney, and Jolene Varga and Rob Ronci.

We thank Executive Director Joaquin Ruiz and Deputy Director of Research Cherry Murray and the whole of the Biosphere 2 staff for continued, daily support; Murat Kacira and Gene Giacomelli of the University of Arizona Controlled Environment Agriculture Center; and Doug Hocksteed and Rakhi Gibbons of TechLaunch Arizona for the initial round of funding. Jude Yandow was instrumental in keeping the finances in order and Julie Stringer for helping us navigate the complex framework of the University.

We look forward to returning in September to dive back into SAM construction, with the first of three shipping containers already in place for the 1200 sq-ft crew living quarters.

See you then!

We did it! We completed the first seal of the fully refurbished Test Module at Biosphere 2! The experience was extraordinary, a true celebration of the effort to bring this iconic prototype pressure vessel back to life!

The day started with long-time B2 electrician Kevin installing a new 100A, 3-phase disconnect in our primary panel at SAM. Then Chris Kaufmann, Brian Scott, Neal Barto, Emma Menden, and Michael Mason from University of Arizona CEAC delivered, assembled, and transplanted a full suite of food cultivars (some 180 in all), the first to arrive to SAM. Trent moved the CO2 scrubber into place while John and Kai established a base-line for the sensor array, both internal to and external to the sealed Test Module. Leonardo Buono, a veteran filmmaker was on-site for the entire day to both film and manage the lung inflation fan and valve.

With a few words spoken prior to entry, the crew walked inside and sealed the door.

Kai Staats, Trent Tresch, John Adams, Katie Morgan, and a writer were sealed inside for four and a quarter hours. While monitoring the CO2, O2, temperature, relative humidity, and barometric pressure, they played Xtranaut, a board game developed by Dr. Dante Lauretta at the University of Arizona, Principal Investigator for OSIRIS-REx, the spacecraft that is returning a sample from the carbonaceous asteroid Bennu. Finally, this first team to enter the fully refurbished Test Module assembled a FarmBot, an open source precision agriculture CNC farming tool. Our unit was donated to SAM by founder Rory Aronson. It is beautifully constructed, an elegant machine we are eager to employ later this year.

This marks the first time in 30 years that humans have been sealed inside the Test Module and the completion of Phase I construction of SAM, a Space Analog for the Moon and Mars at Biosphere 2.

We were honored to have colleagues and family waiting outside SAM for the duration of the test run, greeting us as we exited at 8:30 pm with a bottle of bubbly and lemonade. Thank you for your support, and for keeping Leo company!

Now, we have data to analyze, photos and video to process, and six months of work to bring to a close.

Test Module Dry Run | Five Persons Sealed Inside | Data Analysis