Postcards from Mars

As we are constructing SAM from three exiting structures (the original Biosphere 2 Test Module (TM), a 20′ and a 40′ shipping container) no two interfaces between these units is identical. Rather, each is an experiment in design where the corridor must be ridged to support the weight of a human passing inside, protected from the elements so as not to rust or degrade over time, and attached on both ends so as to maintain a pressurized seal between dissimilar materials.

We learned a great deal in the study of the TM. The 5’x5′ windows are held in a steel frame which itself it bolted to the TM. A 3/4 inch channel between the inside of the window frames and the steel frame of the TM is filled with 795 silicon to provide a pressure seal and low-permeability gas release over time. This system has remained untouched for more than 30 years and remains 100% sealed, even flexible to the touch. It was our intent to duplicate this method for all interfaces, however, we determined that the effort would result in more welding overall than simply welding the interfaces themselves.

As such, we asked James Parker, Supervisor of the University of Arizona Metal Shop to let us know when his team could give us a full day at SAM. On August 18 Charlie and Steven applied their expertise, successfully welding the side walls, tops and bottoms of the corridor between the Test Module and 20′ container, and between the 20′ and 40′ containers. Kai removed the insulation from the exterior prior to the welding team arrival, and when complete (and cool to the touch) applied a coat of primer to the exposed areas, then replaced the insulation sheets.

And with the close of June, first week of July already come and gone, we are departing Biosphere 2 for our second summer, returning in early October to initiate the final three months of SAM construction, conduct pressure tests, and prepare for our first team arrivals in early 2023.

See you then!

With the final three weeks of work at SAM, John Z., Luna, and Kai completed many small projects, wrapping up loose ends to the second, entering third phase of construction. Luna replaced more than 300 original nuts and washers that hold the sealed windows in place with stainless. The skylight mounted as the bathroom window was temporarily removed to apply a generous layer of Dow-Corning 795 silicone (the same used on the Test Module and Biosphere 2) and reset. The variety of tomatoes grown inside the Test Module for the Analog Astronaut Conference produced delicious fruit, were consumed, the plants composted. Several afternoons were spent loading aluminum stays and struts, scrap metal from the roof panel installation for delivery to the roll-off metal recycling bin behind the B2 Energy Center.

For a sum of three weeks John Z., Luna, Kai, and Sean insulated the 20 foot shipping container which will serve as the workshop for SAM. The panels were provided by InsoFast, a low VOC product specifically manufactured for a given shape of container (thank you Angus for the recommendation). While the installation video showed professionals completing a 20′ container in 12.5 minutes, we required something closer to 12.5 days (maybe a bit more). It’s tedious, exacting work but in the end, a good solution. The built-in “studs” provide support for 500 lbs and provide a high “R” value and moisture barrier of close-cell foam.

MrCool manufactures an innovative, do-it-yourself mini-split heat pump—an air conditioning unit with both the condenser and lines pre-pressurized with coolant. It really is quite clever and relatively simple to install, requiring only two crescent wrenches, two screw drivers, hole saw, PVC tape, and some careful planning. We probably spent as much time in measurements as in the actual hands-on effort, which paid off. Given that SAM is not your normal house, we were very careful to consider how we would maintain the hermetic seal given the need to cut a hole through the wall of the insulated 40 foot shipping container. Our solution was simple: we placed a patch of PVC tape over the hole which houses the pressurized lines and electrical line for the air handler, and cut an “X” incision to push each line through with minimal exposure. From the outside we re-filled the space between the interior stainless steel, and exterior aluminum skin with spray foam that pressed against the PVC tape, expanding to the outside again. Now, spray foam is bonded to spray foam in that insulated cavity and we hope, sealed. The outside of the hole is covered by a water tight electrical box leading to the insulated, pressurized coolant lines for maximum thermal retention.

For now, the unit runs off an extension cord (measured 7A, max 11A at 110V) and will be properly hard-wired once we run additional lines from the main feed. Within thirty minutes the Crew Quarters was a cool 78F compared to the 100F+ outside. It works! And we are set for the summer.

Two years ago this summer the SAM development team met via Zoom to discuss the best way forward for the Space Analog for the Moon & Mars. At that time, it had been our intent to move the Test Module, piece by piece, from its original location to the north yard of the Biosphere 2. This difficult task was, at that time, intended to give maximum exposure to SAM as it would be directly on the tourist walking path and in the shadow of Biosphere 2 proper.

However, through conversations with individuals at NASA we were reminded that for long-term missions isolation from tourists would be ideal, off the main campus with minimal disturbance. Furthermore, we could drastically reduce the cost of construction by leaving the Test Module on its original, sealed foundation. Once we changed that mindset, it opened a whole new way of embracing the project. And as is often the case, we saw what was right in front of us as something wholly beneficial with incredible potential.

When Biosphere 2 was opened in 1991, the visitor center and parking was above the Test Module. Tourists walked past the Test Module and a half acre botanical garden complete with working simulations of the biomes inside of B2. In this manner, tourists could experience some of the interior environment and learn about the analog experience without being sealed inside.

Last summer we removed five greenhouse structures to make way for our exterior Mars yard, a space that will be reconfigured for long-duration teams and for rover competitions. We retained the 6,400 square foot rain forest greenhouse with intent to replace the former plastic panel roof with corrugated, galvanized steel. In March we removed the remaining plastic panels (most had fallen to ruin after thirty plus years) along with a massive amount of aluminum framing, steel cables, and no-longer-in-use electrical components. Just two weeks ago we rented a scissor lift to complete this effort, the articulating ridge lines of each half dome removed.

When complete, the full steel roof far overhead, we will greatly reduce the thermal load on the Mars yard terrain, offer shade for crew members in already difficult to cool pressure suits, and reduce the ambient lighting to something closer to Mars than the direct, Arizona sun.

It took six months of research and negotiation to find a local company willing to work with this unusual building and within our limited budget. We are pleased to have engaged Skyland Roofing of Tucson, Arizona. The crew worked through difficult conditions, from 104F+ degrees to wind and rain, on scissor lift and cherry picker 24-40 feet off the deck. Thank you Skyland, foreman Mario, and crew Louis #1, Louis #2, Kevin, Elia, and Adrian for your services. And thank you LP Steel of Laveen, Arizona for the custom-made roofing panels delivered on time and at a reasonable price.

Following the Analog Astronaut Conference, the entire team took a well deserve break, a week without hammer, drill, construction adhesive, or paint in hand. Kai Staats was then in Washington D.C. to present to and participate in the National Space Society’s International Space Development Conference while John Z. and Luna constructed a prototype sleeping pod.

In preparation for the installation of a new corrugated steel roof over the indoor Mars yard at SAM, Luna and Kai spent two days on a scissor lift (photo at top) removing the remaining aluminum framework that held the articulating roof panels across the two ridges. Next week the contractor arrives to install the new roof. With just three weeks remaining in construction at SAM until October, it is our intent to install insulation in the workshop (20 foot shipping container) and a mini-split air conditioning unit in the crew quarters (40 foot shipping container), and continue our work toward the hermetic seal of the expanded habitat.

Stay tuned for more!

By Luna Powell

Given feedback from Kai, Sean Gellenbeck, and Anastasiya Stepanova whom have collectively attended four habitat analogs (MDRS, HI-SEAS, SIRIUS, Devon Island), we determined that the team members staying in SAM will benefit from their own private space to sleep, decompress, and work. This may seem obvious, but there are analogs (and real-life environments) in which private space is not afforded such as lava tube and submarine analogs, and the International Space Station.

We narrowed our brainstorming and initial designs to an enclosed sleeping module. While Kai was attending conferences around the U.S. mid May to early June, John Z and I turned our attention to creating an enclosed, private sleeping quarters prototype for future SAM crew members. We drew it out, purchased the materials, and built the prototype.

The idea was simple: an enclosed, insulated, sturdy, module with personal storage, bed, ventilation, and plenty of privacy. There will be 4 placed at the end of the 40ft shipping container, stacked and arranged with a sufficient amount of storage space as well as a place to sit on top, to create a vertical component to the shared common space for reading, resting, or working with a laptop.

Using ecoboard, backerboard, 2x4s, insulation foam, a substantial application of construction adhesive, and a bit of trial and error, the prototype took shape. The box itself sits around 87″ long, 33″ wide, and 47″ tall granting the person inside plenty of room to lie down, sit up, move front to back and sleep comfortably.

The team still has a plethora of ideas about how to set up a fan system, close off the opening, insert shelving, and much more. But with the close of construction for the summer, these ideas will have to be addressed in October when everyone returns.

In the final days before the Analog Astronaut Conference 2022, hosted at Biosphere 2, the SAM construction and fabrication team worked tirelessly, from sunrise to sunset to get as much of SAM ready as possible for the more than 100 attendees. While most of the effort was on the task list for Phase II, some undertakings were temporary, a light treatment of a room or space to provide visitors a glimpse of what will come.