Postcards from Mars

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SIMOC and SAM featured at Sky-Lights, by science educator Dan Heim

Self-sufficient life support diagram by Dan Heim Former high school physics professor, lifelong amateur astronomer, and author of the Sky Lights, a weekly blog about things you see in the sky (and some you can’t see). Dan’s animated essays cover a wide range of disciplines including astronomy, meteorology, climatology, chemistry, physics, optics, earth & space science, and others.

This past two publications Dan has discussed Surviving in Space, with an emphasis on what it would take to make the International Space Station self-sustaining versus a habitat on the Moon or Mars. Dan writes, “Last week we looked at whether the ISS could be made totally self-sufficient and never require supply missions from Earth. The short answer was “yes” but the practical answer was “no”. However, in a colony on a moon or planet where outside resources (like water and minerals) are available, self-sufficiency is much easier.”

Surviving in Space – Part 1 and Part 2.


By |2021-05-13T06:07:55+00:00April 5th, 2021|Categories: Education|0 Comments

Mars City Design and Company visit SAM

Vera, Bret and Sangita, Jasleen, Rafael, Hillary at SAM, Biosphere 2

Vera Mulyani, founder of the Mars City Design and her associates Bret and Sangita, Jasleen, Rafael, and Hillary were welcomed visitors to Biosphere 2 and SAM. Deputy Director John Adams provided an hour and a half personal tour of the Biosphere 2 facilities prior to a tour of the construction site for SAM. The day held engaging conversations about NASA, SpaceX, the contribution of analogs to human space exploration since the 1960s, and how Kai and Trent are two opposing variables in a dynamic, balanced equation.

From left to right: Rafael Martinez, Hillary Coe, Kai Staats, Bret and Sangita Engelkemier, Vera Mulyani, John Adams, Katie Morgan, Jasleen Gujral.

By |2021-04-30T06:30:08+00:00April 5th, 2021|Categories: Visitors to SAM|0 Comments

SAM Construction – How to build a greenhouse on Mars

Walking on air at SAM, Biosphere 2

Having completed our first application of a 100% silicone elastomeric on the exterior roof panels of the Test Module lung, we felt confident in our ability to apply the same to the top of the iconic Test Module itself. It may seem odd to cover glass with a opaque, reflective coating, but our intent is clear — we intend to eliminate the direct lighting of the greenhouse of SAM to more closely approximate an exterior structure on Mars where concern for radiation would, given our current understanding and technology, keep us from long-term exposure. While most structures will likely be bermed if not buried by a few meters of regolith, this coating drastically reduces the interior light and does in fact provide a sense of being enclosed.

The cleaning of the glass was no small undertaking. Thirty odd years of dust and rain baked onto the glass does not readily wash away. We used a high pressure sprayer run from the desk of a cherry picker, then scrubbed each window pane by hand with water, TSP, and vinegar.

By |2021-04-27T17:19:47+00:00March 30th, 2021|Categories: Construction|0 Comments

SAM Construction – MDRS Lends Four Hands

Linnaea Groh at SAM, Biosphere 2

This week we have had the great pleasure of receiving two volunteers from the world renowned Mars Society Mars Desert Research Station (MDRS). Linnaea Groh and Atila Meszaros drove overland from Hanksville, Utah to spend a few days working on SAM. For four cold, wet days they removed tree roots, sanded, and painted. We thank them for a stellar close to the month of March!

Linnaea Groh at SAM, Biosphere 2 Atila Meszaros at SAM, Biosphere 2

Linnaea Groh at SAM, Biosphere 2 Atila Meszaros at SAM, Biosphere 2

Shannon Rupert, Director of MDRS was unable to visit at this time due to obligations with her own habitat analog. We look forward to having you to SAM soon! –kai

By |2021-04-23T05:11:29+00:00March 26th, 2021|Categories: Construction|0 Comments

SAM Construction – Selecting window film for the Test Module

Window film test at SAM, with Trent Tresch and Kai Staats

The 1987 Test Module (prototype for the Biosphere 2) will be the controlled environment / greenhouse for SAM. Many simultaneous plant studies will be conducted in the Test Module, including the growth of food cultivars to offset groceries introduced at SAM, mushrooms as a means to convert inedible biomass into digestible nutrients, and algae as a carbon dioxide (CO2) sequestration agent in addition to the variety of plants contained therein.

Trent Tresch testing window film irradiance rejection at SAM, Biosphere 2 We recognize that a greenhouse such as the Test Module is not a structure that will be built on Mars, at least not in its current form. There are four reasons for this: a) radiation that the Martian atmosphere is too thin to mitigate and that glass does not reject; b) ability to manage the high pressure differential between the interior and exterior; c) ability to manage the extreme temperature differentials; and d) low ambient light for plant growth, just 590 watts per square meter on Mars compared to 1000 watts per square meter on Earth, both measured at zenith. Nearly all food cultivars will require additional, synthetic lighting even if routinely exposed to full sunlight on Mars.

Therefore, we are modifying the Test Module to more closely represent a greenhouse structure on Mars, if one were to be built above ground. All surfaces facing up (the greatest exposure to radiation through the least amount of Martian atmosphere) will be painted with a reflective, white elastimeric to represent radiation shielding or regolith. The vertical glass panes (base level of the TM) will be tinted darker to reduce the ambient optical transmission by approximately 50% to match the 590/1000 watts per square meter reduction from Earth to Mars. What’s more, each film rejects between 75-85% infrared light, drastically reducing the thermal load on the total structure and thereby reducing power consumption by the mini-split air conditioners.

We used a Canon 60D camera with Tokina 12-24mm zoom lens set to a fixed ISO 250 and shutter speed 1250. We then held each of eight window films to the front of the lens and took a photo with no adjustments made. After the photo, we adjusted the f-stop ring to move the light meter back to its center, zero calibration. The difference between the two indicates the amount of light reduced, from the point of view of the camera sensor behind the film.

These are the results of our study.

e-film test at SAM - baseline

  • Baseline, no window film applied
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8 for a neutral lighting
  • Visible Light Transmission: 100% (not including the glass itself)


e-film test at SAM - 1DS-50 Neutral

  • Window film: 1DS-50 Neutral
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 6.5
  • Visible Light Transmission: 60% with glass


e-film test at SAM - Therm-X 50

  • Window film: Therm-X 50
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 6.5
  • Visible Light Transmission: 47% with glass (see discussion below)


e-film test at SAM - SYDS-50 Dual Reflective

  • Window film: SYDS-50 Dual Reflective
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 5.6
  • Visible Light Transmission: 47% with glass


e-film test at SAM - Ceramic 45

  • Window film: Ceramic 45
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 5.6
  • Visible Light Transmission: 42% with glass


e-film test at SAM - SYDS-35 Duel Reflective

  • Window film: SYDS-35 Duel Reflective
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 5.0
  • Visible Light Transmission: 40% with glass


e-film test at SAM - Ceramic 35

  • Window film: Ceramic 35
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 5.0
  • Visible Light Transmission: 31% with glass


e-film test at SAM - Therm-X 30

  • Window film: Therm-X 30
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 5.0
  • Visible Light Transmission: 27% with glass


e-film test at SAM - SDS-35 / SXT-35

  • Window film: SDS-35 / SXT-35
  • Canon 60D, ISO 250
  • Shutterspeed 1250
  • Photo at f-stop 8, adjusted to neutral at f-stop 4.5
  • Visible Light Transmission: 26% with glass


The aperture of a camera lens is measured by the f-stop value, a ratio of the focal length of the lens (entry point of light to the exit) divided by the diameter of the aperture, or the opening created by concentric sheets of thin metal that converge around the center. The larger the opening the more light that enters, thus the shorter depth of field; the smaller the opening the less light that enters, thus requiring a longer exposure and greater depth of field.

A good explanation is given by the website Expert Photography.

The full f-stop values are as follows: f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, …

Where f/1.4 is the largest and f/64 is the smallest opening, each increase in value in the denominator represents a 50% reduction in light. From f/1.4 to f/2 is a 50% reduction, again from f/2 to f/2.8, and so forth. For those inclined to take the mathematics a bit further, use the formula for the area of a circle (pi * radius squared) to approximate how these values relate to the opening of the aperture.

Canon 60D image info for window film tests at SAM, Biosphere 2 Now, we will determine which level of visible light transmission (VLT) is a good approximation to that of the average, ambient sunlight on Mars. We started with an f-stop setting of f/8. The first window film 1DS-50 Neutral invoked an f-stop of f/6.5 to bring the light meter back to 0. This is a half stop, or roughly 25% reduction in VLT. The Therm-X 50 seems to be incorrectly rated or the camera did not register properly, as its 47% VLT does not match the 75% transmission seen by the camera.

The SYDS-50 Dual Reflective and Ceramic 45 both invoke a full stop, from f/8.0 to f/5.6 which is a 50% reduction in VLT and closely matches the stated 47% and 42% VLT per the product specs. If we had a more finely graduated light meter than the one built-in to the camera, we might see values closer to the window film specs.

With the remaining window films the f-stop value moves to f/5.0 (another half stop) and f/4.5 for the darkest (two full stops from the original, unfiltered f/8.0) for a 75% reduction in light which perfectly matches the window film manufacturer specs of 26% VLT.

Furthermore, we will choose a non-reflective film such that visiting researchers to SAM will not feel boxed into the Test Module at night where interior lights would reflect back. While the windows will be darker, we do want for our analog astronauts to enjoy the Moon, planets, and stars overhead to retain a sense of the vast cosmos despite their relative isolation in the sealed SAM habitat.

It appears the Ceramic 45 window film will give us the closest approximation to the visible sunlight on Mars.

“We thank Greg Spencer, owner of AGTP Window Films from Tucson, Arizona for provision of the window film packet used in this comparative study. We discovered Greg through a local search and subsequently learned that his company was on-site at Biosphere 2 in 1991 having applied films to the Biosphere apartment windows and campus facilities. With more than 40 years experience, we are not surprised that most of those applications are yet in place and holding!

Greg has generously donated his time and materials for this unique project. We welcome the return of “Greg the Tinter” to Biosphere 2, and are eager for his high quality product to be installed at SAM. Thank you!” –Kai Staats, Director of SAM

By |2021-04-23T05:11:36+00:00March 18th, 2021|Categories: Construction|0 Comments

SAM Construction – Test Module lung membrane removal

Trent Tresch using an impact wrench to remove the Test Module skirt, SAM at Biosphere 2

After washing and scrubbing the Hypalon membrane of the Test Module lung, we attempted to remove the bolts that hold the lung membrane in place using an angle grinder, only to realize that we had dozens of hours ahead of us and an unspeakable amounts of debris from the process. Then it occurred to us that a high torque impact wrench would either remove the nuts from the welded studs or snap them off (they have to be removed anyway). We borrowed a massive DeWalt from the Biosphere 2 Energy Center and jumped right in. In less than two hours we had the metal ring sections removed and the membrane pealed free.

For the first time in thirty four years, the Test Module lung is disassembled! Now, the real effort begins as we must remove the studs and return the top flange to a pristine state before attaching all new steel studs with which the Hypalon membrane will be reattached and sealed.

Trent Tresch washing the Hypalon membrane at SAM, Biosphere 2 Kai Staats scrubbing the Hypalon membrane at SAM, Biosphere 2

Kai Staats removing water from the sill of the Test Module lung, SAM at Biosphere 2 Trent Tresch removing bolts from the sill of the Test Module lung, SAM at Biosphere 2

By |2021-04-23T05:13:30+00:00March 17th, 2021|Categories: Construction|0 Comments

SAM Construction – CO2 Scrubber from Paragon SDC

CEO of Paragon Grant Anderson explaining function of CO2 scrubber for SAM Loading CO2 scrubber for SAM at Paragon SDC

Loading CO2 scrubber for SAM at Paragon SDC Loading CO2 scrubber for SAM at Paragon SDC

After a week break from construction, Kai Staats visited Paragon Space Development Corporation, a partner in SAM design and implementation. CEO and President Grant Anderson has given SAM two CO2 scrubbers: one to experiment with, the other the foundation for what will operate in the living quarters to maintain safe levels of carbon dioxide. Trent Tresch and Kai Staats are conducting research into the most practical and energy efficient means to recycle soda lime such that the adsorption beds will be rotated on a daily basis when a full four crew members are in place.

By |2021-04-23T05:13:33+00:00March 16th, 2021|Categories: Construction|0 Comments

SAM Construction – At the Close of Six Weeks

Sunset over Biosphere 2, by Kai Staats Six weeks have come and gone as though they were just a few days and at the same time a full year in the renovation of the Test Module at Biosphere 2 (B2). The first days were completely overwhelming, Trent and I covered cap to boot in dust, rust, and thirty years of grime. With the steadfast help of B2’s Tim and Terry, and three weeks effort by Cameron too, we moved beyond grinding, sanding, and cleaning to the tipping point of starting to put the Test Module back together again.

All twenty one of the ports are once again sealed, save a single, large hole in the plate steel foundation wall. The stainless steel floor is scraped and scrubbed and the overhead spaceframe dust-free, awaiting a final power wash and cleaning. The outer perimeter is primed, and the top of the lung sealed with an advanced silicon sealant called “795”, the same that has kept the windows sealed at Biosphere 2 for thirty-plus years. Next we paint the outside of the lung cover, seal the vertical plates, apply an elastomeric to the roof and then dive back inside to repair the lung, more than 200 bolts to replace.

The mechanical engineer is completing a final assessment for the potential thermal load in the dead of summer, and then we purchase and install the mini-split coolers. With a reflective coating applied to the upper glass panels to reduce the thermal load and more closely approximate the 50% solar radiation on Mars, we hope to come in with a significantly reduced power consumption over the original Test Module, our goal to go grid-tied or fully off-grid in the coming year or two.

On Monday, March 15 we take possession of a CO2 scrubber designed and built by Paragon Space Development Corporation for a NASA funded research project, and then dive into the modifications and upgrades to suit the demands of a rotational, four-person crew.

Day by day, we check boxes and add more to the long list of TODOs. Day by day we make progress and come closer to our goal, construction of a hi-fidelity Mars analog at Biosphere 2.

By |2021-04-23T05:13:36+00:00March 5th, 2021|Categories: Construction|0 Comments

Biosphere 2 Deputy Director John Adams conducts pressure suit test at SAM

Biosphere 2 Deputy Director John Adams conduct pressure suit test at SAM

A decade ago archaeologist at Portland State Dr. Cameron Smith redirected his knowledge and passion for human history toward the future of our species as we become interplanetary. His academic publications and books project a social—even biological evolution as we move to the planets and stars.

Suit sketches by Cameron Smith Cameron launched Pacific Spaceflight (PSF) to explore design, construction, and validation of low-cost, fully functional pressure suits that enable every-day citizens to reach the edge of space and beyond. These personal spacecraft are a critical aspect of off-world exploration, no matter if you are at 65,000 feet above sea level, on-orbit, or on the Moon or Mars. More than a novelty, PSF suits have been tested under water, in vacuum chambers, in the open cockpit of aircraft and in high altitude balloon projects. Cameron’s dynamic team of volunteers (including Kai Staats and Trent Tresch of a Space Analog for the Moon and Mars (SAM)) have both contributed to and been influenced by his critical work.

John Adams in a pressure suit, SAM at Biosphere 2 On Tuesday, March 2, at 7:00 am John Adams, Deputy Director of the University of Arizona Biosphere 2 engaged in the other-world journey of donning a pressure suit to conduct a number of tests for mobility and tool use, both of which can be challenging when encumbered by a sealed suit under greater than ambient pressure.

This endeavor was conducted inside and around the historic Biosphere 2 Test Module, now five weeks into a major refurbish and construction endeavor as the cornerstone of SAM. This event was a fully immersed operational test of the equipment, suit, and procedures which SAM researchers will enjoy when a part of this analog experience. SAM has purchased two suits from Smith Aerospace Garments that will be available for team members to use in the half acre SAM Mars yard just outside of the living quarters and Test Module.

The specs for this particular pressure suit are as follows:

  • Suit model: Pacific Spaceflight, experimental Mk SE I (2018-2019)
  • Suit construction: sealed bladder with high-durability outer garment; attached boots and gloves with removable helmet
  • Air composition: standard mix of ~78/21% nitrogen/oxygen levels
  • Pressure inside the suit: ~1.0 psi over ambient
  • Suit pressure max spec: 3.5 psi over ambient
  • Compressed air source: dual feed, oil-free air compressor with 4 gallon reserve

Cameron engaged John in the suit-up procedure for approximately 30 minutes (full photo gallery below). At this time the air compressor inside the Test Module simultaneously fed John’s suit directly and a manifold that enables controlled gas exchange to the outside world. Of his own accord he opened the bulkhead door and proceeded outside. There, his feed line was switched to the manifold exterior. The momentary break from his air source was possible due to the suit acting as a short-duration buffer. SAM teams will carry a small, portable compressed air source that will provide continuous flow as feed lines are swapped from airlock to the hab exterior.

With the assistance of Cameron and Trent, John conducted a basic walk, followed by tool use, ladder climb, CO2 level check, and ascent of the exterior of the Test Module lung. This prototype suit was designed for mobility, but has been surpassed by the current models which will be delivered to SAM by late spring 2021.

In conclusion John shared, “The suit is amazing! I feel really good … all things considered, you still have quite a bit of dexterity, quite a bit of ability to lift your legs, to move around complex objects. To have an opportunity to experience a pressurized suit in a simulation setting is incredible. I feel really fortunate to have this opportunity.”

We extend our thanks to the University of Arizona’s Aaron Bugaj for exceptional photography, Katie Morgan for work with social media, and Megan Russell and Britney Swiniuch for your support and enthusiasm for this first-ever pressure suit test at SAM.

By |2021-04-27T16:57:58+00:00March 4th, 2021|Categories: Research & Development|0 Comments