Airbus ESA Advanced Closed Loop System (ACLS)

Two technicians point to large instrument box.

ACLS technology demonstrator generates oxygen and water in a closed system

The Advanced Closed Loop System (ACLS) is an advanced life support system that has been developed by Airbus for the European Space Agency (ESA) to be used as a technology demonstrator on the ISS, in the Destiny module, from summer 2018. The ACLS will be installed in the HTV-7 space transporter at the Tanegashima Space Center in Japan and is due to be transported to the ISS in August 2018. It is set to be operated for a period of one year.

The ACLS will purify air and produce oxygen for the International Space Station (ISS). Specifically, the ACLS extracts a portion of the carbon dioxide in the cabin atmosphere. Then, using hydrogen obtained from splitting water molecules, it will convert the carbon dioxide into methane and water in what is known as the Sabatier process. Oxygen is then produced from this water using electrolysis. Airbus asserts that this will increase overall system efficiency and hence reduce the need for supplies from Earth.

The main advantage claimed for the ACLS is the use of the adsorbent Astrine, a solid amine resin, which has a high adsorption capacity even at the carbon dioxide levels in the cabin air. The ACLS will be contained in an International Standard Payload Rack (ISPR).

A future use for the ACLS may be for the Deep Space Gateway / Lunar Outpost. NASA is reported to be looking to the ESA for part of the habitat.


Orbital Genomics concept

In addition to blogging, SustainSpace engages in concept and product development. SustainSpace authors Afshin Khan and Mark Ciotola have developed the Oribital Genomics venture converted with astro culture. Recently, the Orbital Genomics concept won ESA Space Explorations Masters prize. 


Plants provide food, breathable air and psychological benefits. With plans materializing for a Deep Space Gateway, Lunar Village and the Mars community, there may be a lot more people living in the lower Earth orbit and microgravity environments, besides on the International Space Station. However, food production in space is still in its nascent stage. Existing prepackaged astronaut food is not a healthy option for long haul space missions. There is no way to regularly transport fresh fruit and vegetables. It is becoming increasingly evident that we must be able to successfully grow food in space.

Plant experiments done on ISS have presented various challenges, such as, years of preparation, little iteration and fewer conclusive results. Furthermore, ISS is limited in its genetic analysis capabilities and there are limited astronaut hours for dedicated biological analysis. Hence, for at least the next decade or more, most analysis of plants and seeds grown in space must be accomplished on Earth, which is not feasible.


Agile approaches by Orbital Genomics aims to adapt, develop and finally grow crops in space to solve the food production challenge in lower Earth orbit and planetary bodies of interest. Additionally benefit agriculture on Earth.

Loop where seeds are launched into space, plants returned to Earth, and successive generations launched.

Concept for rapid evolution of plants for adaptability in space environments.

Market Strategy

We also aim to enter the market as an “astroculture uber-service” for citizen scientists, farmers and agricultural companies, who would be provided with a platform for developing space adapted crops and gaining from space treated crops, to adapt in various challenging conditions on Earth, due to climate change and drought.

Rows representing experiments

Sample dashboard for astroculture-as-a-service concept

Circles containing crops are superimposed on squares containing dry, unplanted or fallow land.

SustainSat brings satellite approaches to Earth

SustainSat is a platform that can be used as either a prototype for CubeSats or as an Earth-based sensor and data-logging platform. It is intended as a low-cost, barebones way to learn about the general categories of technologies used in cubesats as well as to use those technologies for sustainability purposes on Earth.

SustainSat is built around the Arduino prototyping platform. It is different from ArduSat in that it is not specifically set up for use in space. SustainSat technology can be adapted for space, such as through ArduSat. However, SustainSat provides devices ready for use on Earth or on balloons and kites. It is perhaps the lowest-cost, simplest way to explore satellite technology in a sophisticated way, while empowering users to create and adapt real devices.

The simplest form of SustainSat is a simple light monitor, such as for sunlight, combined with an inertial unit. Such a device is similar to a real device that monitors solar luminosity, or a 1 pixel space telescope. It provides guidance data for potential reaction wheels or thrusters.

More sophisticated forms of SustainSat include wireless transmitting and data logging capabilities, as well as other sensors. A version of SustainSat that can capture hyperspectral information is under development.


First Flowers Grown on International Space Station

Commander Scott Kelly (Expedition 46) shared photographs of a blooming zinnia flower in the Veggie plant growth system aboard the International Space Station (16 January 2016).  “Yes, there are other life forms in space! #SpaceFlower #YearInSpace”, Kelly wrote.

Flowers growing on International Space Station

Flowers growing on International Space Station (Credit: NASA)

This flowering crop experiment began on Nov. 16, 2015, when NASA astronaut Kjell Lindgren activated the Veggie system and its rooting “pillows” containing zinnia seeds. The Veggie provides lighting and nutrient delivery, but utilizes the cabin environment for temperaturecontrol and as a source of carbon dioxide to promote growth, according to NASA.

Growing zinnias provided an opportunity for scientists back on Earth to better understand how plants grow in microgravity, and for astronauts to practice doing what they’ll be tasked with on a deep space mission: autonomous gardening. In late December, Kelly found that the plants “weren’t looking too good,” and told the ground team, “You know, I think if we’re going to Mars, and we were growing stuff, we would be responsible for deciding when the stuff needed water. Kind of like in my backyard, I look at it and say ‘Oh, maybe I should water the grass today.’ I think this is how this should be handled.”

plastic accordion plant chamber

VEGGIE prototype (photocredit: NASA)

The Veggie team on Earth created what was dubbed “The Zinnia Care Guide for the On-Orbit Gardener,” and gave basic guidelines for care while putting judgment capabilities into the hands of the astronaut who had the plants right in front of him. The care guide was a one-page, streamlined resource to support Kelly as an autonomous gardener. Soon, the flowers were on the rebound, and on Jan. 12, pictures showed the first peeks of petals beginning to sprout on a few buds.”

Further Information


Call for a Open Source Life Support Toolset

Global Village Construction Set

Global Village Construction Set

Open Source Ecology’s Global Village Construction Set provides a “modular, DIY, low-cost, high-performance platform that allows for the easy fabrication of the 50 different Industrial Machines that it takes to build a small, sustainable civilization with modern comforts.” An important point about machine tools is that they are a sort of ecosystem, where the various tools are used in combination to build each other. For example, a lathe can be used to make many of the components required for a milling machine, and vice versa. This construction set is also open source.

This is analogous to a closed-loop life support system, where the “waste” from one component can provide essential material for processing in other components. For example and animal produces CO2 which is essential of plants, and plants provide O2 which is essential for animals. Other components of this ecology of life include water and nitrogen flows and transformations.

Perhaps there should be a set of open source components of closed-loop life support systems? Standards could be established so that major components could interface with each other. Likewise, components could be interchangeable, so that different parties could work in parallel on different approaches to each component.

Distribution of some existing technologies are controlled by ITAR and patents, but alternatives could be created that do not. Further, different versions of the components could be developed for space versus Earth use, but they still could be subject to interconnectivity standards.

Note: “closed-loop” really means nearly closed-loop. There still would need to be energy inputs and a waste heat output.

Link: Global Village Construction Set

NASA Targets Reduced Water Usage for Long Duration Missions

NASA Water Recovery System

Water Recovery System (credit: NASA)

Water is essential for human survival on Earth and in space. A typical person requires between 3.5 to 15 liters per day. Yet launching large quantities of water up to the International Space Station (ISS) is terribly expensive, and would be a major impediment to future space settlement. So NASA has made water recycling a vital part of closing the life support “loop”. Meanwhile, water is often in short supply even on the Earth, especially in a clean, drinkable form.

First Steps

Russia’s space station Mir recycled cosmonaut sweat. An earlier NASA method of water re-use involved separating waste water into hydrogen and oxygen. The oxygen could be used for breathing and thus reduce the amount of oxygen that needed to be transported to ISS (NASA 2008).

NASA’s Current System on the ISS

NASA’s current water recycling system on ISS is the Water Recovery System (WRS), part of the Environmental Control and Life Support System (ECLSS). WRS water purification machines on the ISS cleanse wastewater in a three-step process. WRS first filters out particles and debris. Then, urine is processed though vapour compression distillation (VCD), while humidity condensate passes through multi-filtration beds to remove organic and inorganic impurities.

Products of the vapour and multi-filtration are mixed together and passed to a catalytic oxidation reactor that removes volatile organic compounds (VOC) and kills bacteria and viruses” (Carter at al. 2008). This system is designed to recycle about 90% of ISS waste water. ISS occupants are supplied with hydrated food that makes up the remaining 10%.

Watertech International device

(credit: Watertech International)

Similar technology is also being used in the field. Waterlife International produces a unit for local use. They have engaged in projects in Kenya, Rwanda, South Sudan and Cambodia. They are in talks to supply a provincial government in South Africa. Also see the Water Security Corporation.

Next Generation System

To do even better, the Alternative Water Processor (AWP) is currently being developed by NASA’s Next Generation Life Support Project, under the Game Changing Development Program.  It will support a crew of four each with 11 liters of water per day on a long-duration space flight mission. On such missions, food will likely be freeze-dried rather than hydrated, so it will not be available as a source of water. Hence, the newer AWP must have an even higher recovery rate than the older WRS.

AWP has a membrane-aerated bioreactor to destroy organic contaminate and a forward osmosis secondary treatment (FOST) system to remove dissolved solids. FOST uses saltwater as the drawing solution, then reverse osmosis is used to remove the salt, according to Michael Flynn, a research engineer at the NASA Ames Research Center.  (Also see NASA 2013)

Water Recovery System

FOST water processor (image credit NASA)

Construction of the first generation FOST was recently completed at the NASA Ames Research Center. The  system recently shipped to the NASA’s Johnson Space Center. FOST will undergo integrated testing with the membrane-aerated bioreactor, designed by Texas Tech University and constructed by NASA Johnson Space Center.  (NASA 2013)

“Inside the water recovery system is an evolving set of technologies with great promise,” said  Flynn. “Ultimately, these systems will continue to evolve and become increasingly more complex, integrated and smaller.”  (NASA 2013The new system has two major advantages. First, it allows for 95% recycling of waste water. Part of this improvement is due to the use of bioreactor to treat urine, which will avoid the need for highly toxic chromic acid. Second, the new system also processes a higher volume of waste water, so that crew will be able to engage in a greater range of water usage, such as hand-washing and laundry. Also, this new system is lighter, takes up less space and requires less energy per gallon processed, so it is better-suited for long-duration missions.

Bringing It Back to Earth

Sustainability Base water recycling system

Sustainability Base water recycling system

NASA’s FOST system is already finding use on Earth. NASA researchers installed a larger version of FOST in its Sustainability Base, which in combination with other water-saving technologies integrated into the building, is expected to reduce greywater consumption by more than 90 percent. (Total tap water usage is reduced by 40%.) Flynn points out that additional capabilities of FOST in the Sustainability Base include the ability to do long duration testing and failure prediction. It is certainly safer to do this on Earth than in space.

The Future

NASA’s next step may take inspiration from living systems, according to Flynn. Biomimicry is a form of engineering that imitates living systems. For example, in the human body, the small intestine is a highly efficient water absorption and filtering system that works reliably for many decades. It is also self-repairing. NASA is looking towards designing a system that emulates the positive qualities of the small intestine.

A Brief Lesson in Water Filtering

Knowing a few terms can help understand NASA’s technology. Water is typically recycled from several sources. Greywater is waste water from showers and sinks, and can include water from humidity. Blackwater contains fecal matter and urine, such as from toilets.  Reverse osmosis (RO) uses physical pressure to push water through a filter. In contrast, forward osmosis (FO) draws water through a filter using an ionic medium such as sugar or salt water, and has several advantages, such as reduced pore clogging.