Postcards from Mars

The Mars yard at SAM is complete, save the near-future introduction of crushed basalt and basalt boulders to cover the currently exposed concrete slab. The Reduced Gravity Simulator is fully operational, with the prototype built principally from wood being rebuilt in welded aluminum over the summer for a lighter, more stiff frame and smoother operation.

And then came the scenics, a breed of artist unlike the plasterers or the sculptors before them. Quiet like the brushes they employ, subdued like the hints of red, butterscotch, and gray applied, Juan, Danni, and Christina also see the world in three dimensions—not as massive blocks of carved foam or layers of sprayed concrete, but in concentric applications of paint that build depth in color through time.

Referring to the same set of laminated photos as the two prior teams, the scenics apply dark hues beneath overhangs to create permanent shadow, and they create a sense of time through the hi-lights on the leading edges of rock ledges, mineral stains from long forgotten (even if geologically recent) movements of water. And when Danica or Kai would note a synthetic rock surface too bright or too bold for the atmosphere of Mars, within minutes color theory became color reality and the issue was resolved without hesitation or complaint for the second or third effort on that same section of the SAM Mars yard.

The transformation of Polystyrene foam blocks into a Mars landscape requires vision, skill in sculpting, shooting concrete, and painting; and effective management. The first and last are exemplified by Red Hen founder Danica Vallone who maintains a relationship with some 250 individuals working in set design and construction, and her brother and production manager Demian Vallone who brings patience, diligence, and hands-on collaboration to the construction floor. At the SAM Mars yard Danica and her team have transformed drawings and photographs into three dimensions, demonstrating a deep understanding of form, texture, and color and the physical tools used to employ them.

The sculptors (as noted in prior blog entries) hold what is perhaps the most challenging of the processes— making those first cuts into the massive blocks of foam with a vision toward the end product that they may never see. This process is principally one of subtracting material, cutting into square blocks to remove initially large and then increasingly smaller pieces using hot wire knives, chain saws, horse brushes, three pronged picks, and an assembly of home-built hand and power tools. Material is added too, building beyond the otherwise imposed limit of a wall or corner, as with the rockfall in the southeast corner of the SAM Mars yard.

With the shapes established, the plaster crew covers the foam with a thin layer of a custom blend of Poly-bond structural concrete, sand, and adhesives designed to bond to foam. This concrete is tinted to establish a base color such that the final, painter crew can work from that base color with less effort and material, as compared to starting from a standard concrete gray.

While Hollywood sets built from foam are typically covered with 1/8″ concrete, thicker for areas on which actors might walk, the SAM Mars yard is 1/4″ nominal with the west wall K-rock covered in expanded steel, steel mesh, and in some areas up to two inches hand-troweled concrete.

Three sculptors were at SAM for eight days. The four plasterers are slated for just two days (starting today). And as of this coming Sunday two painters will be at SAM for four days. Each crew brings to this project some of the finest talent in Hollywood, with individuals who have two or three generations in skill and experience in their respective trades. The quality of production against an impossible timeline has been truly awe inspiring and points directly to Red Hen’s ability to manage such a complex endeavor.

BELOW: Luna Powell scatters real stones obtained from a local quarry on the shelves and outcrops of the north wall as the plaster team applies the first layer of shocrete to the south wall of the SAM Mars yard. The blue color is a layer of “Weldcrete”, a kind of chemical adhesive that helps the Polybond-based shotcrete adhere to the foam.

(Above) Kai Staats installs simulated pathways for Mars gypsum deposits—nylon rope pinned to foam blocks to be covered by shotcrete and then hand painted, perhaps encrusted with real minerals embedded in an epoxy resin in a later phase.

The sculptors completed their work in foam, applying final textures and geological interfaces while SAM team member Matthias applied expanded steel and mesh to the K-Rock feature, reinforcing the areas on which SAM crew members might walk while on EVA. The existing concrete slab was covered by rose paper before Demian of Red Hen sprayed the blue Weldcrete adhesive, providing a chemical adhesion layer between the foam and shotcrete.

In the SAM Mars yard at Biosphere 2, the sculpted foam provides the robust shape of sedimentary layers, lava, solidified dunes, and rockfalls that define the very challenge of the geologist to unravel time. The application of the concrete gives solid form and texture to the otherwise too fragile structure made principally of trapped air. And while the two of these alone are ample to give visitors to this Mars yard a story to discover, it is the subtle shifts in color that make clear the differentiations of an ancient lake bed from the unconformity on which it lies or the iron concretions about to break free from the shelf on which they lie.

But when all the images captured by rovers on Mars for more than forty years are digital in origin and processed by computers, How does one know the true colors of Mars?

We called upon the distant Spirit, Opportunity, Curiosity and Perseverance rovers, reviewing myriad photos they have generated against the same color metrics applied to the photos received on Earth by NASA and countless university students and researchers. The on-board Mars rover color calibration targets provide a baseline to inform how one might adjust the pixel values, from the raw image to a color balance given the atmospheric conditions of that day, to what that landscape might look like if on Earth instead. The latter becomes important as we compare features on Earth to those on Mars in order to ascertain their origin.

SAM team member and planetary geology student Tasha Coelho built an image deck based on her work in Dr. Jim Bell’s lab at the School of Earth and Space Exploration, Arizona State University. Luna Powell then prepared six sample tints for the baseline concrete color upon which the painters hired by Danica Vallone of Red Hen Industries will push and pull highlights and shadows to give this one-of-a-kind construct its own life.

Sunday, April 21 began with an all-hands team meeting led by Danica Vallone. The prior two days with geologist Christopher Hamilton has altered the design to a degree that required a reset for some of the design expectations. Kai, Tasha, and Luna had printed a few dozen more images at various sizes and zoom factors. Danica then pinned them to the design board, a 6″ thick foam sheet with a marker rendering of the south wall, where each photo provided the required detail for the sculpting team to move ahead.

Monday, April 22 saw the sculpting team regain their anticipated rhythm with steady forward progress, the otherwise nondescript block of foam becoming recognized features, even to the untrained eye: a massive rock fall over an ancient lava flow adjacent to an even older evacuated lava tube.

Tuesday, April 23 began with a spray foam team arriving from Phoenix, setting up their air flow tent, and then applying a #4 density foam to the inside and outside of the rebar, chicken wire, and burlap lava tube built by Matthias, Luna, Kai, and Sean. During the spray foam endeavor, Kai took the sculptors Steve, Rob, and Kat on a tour of Biosphere 2.

Lava tube set and strong enough to walk on (but we won’t), the sculpting team returned their work (donning respirators) while the spray foam crew cut loose the over-spray and cleaned up.

As the Red Hen team moved into the afternoon of its third day in construction of the SAM Mars yard, University of Arizona professor of Planetary Geology Dr. Christopher Hamilton arrived for his first visit to SAM. Following a brief introduction to the project and tour of the initial representation of geological features on Mars, Chris dove in with the full fervor and intent of an actual geological survey and research project.

Over the course of Saturday afternoon and Sunday morning Chris spent the better part of six hours with Director of Research for SAM Kai Staats, ASU planetary geology student Tasha Coelho, and founder of Red Hen Danica Vallone to guide development of details for features already carved in foam, then formulate the juxtaposition of layers not yet sculpted in order to tell a cohesive story for the total, exposed stratigraphy. Once complete, the SAM Mars yard will tell a realistic geologically story.

Kai, Danica, Tasha, and Chris moved between the Mars yard and the SAM Operations Center to compare photographs of rock layer examples on Earth and Mars to the proposed layering of this unique facility, then print and laminate images for the Red Hen sculpting team to employ.

Chris was tenacious, generating on-the-fly a complete strata profile with which the SAM geological story can be understood. Or for those engaged in an EVA of geological discovery, investigate the layers and features presented in order to generate their own map, then compare to the intended sequence developed by Chris.