Controlled ecological life-support systems for space exploration

In 2016 we could see what can be start of space travels renaissance: awesome Elon Musk Mars Colonization Project, private piloted spaceships developments, present and future robotic missions to the far outskirts of the Solar System and many other news.

There are also big news about cheaper space access with reusable rockets, new space telescope and almost every day we hear about new exoplanets discovered.

One of most important elements for human space colonization is controlled ecological life support system (CELSS). It will be impossible to supply future space expeditions with air, water and food from Earth, if you are going even to the moon, not speaking of Mars and beyond. Usually every post about such systems starts from such picture:

OK, the picture is beautiful, but what is situation with real developments in this field?

Surprising answer: for the last 50 years there were only three serious projects with CELLS (on Earth, of course). Here there are (chronologically):

1. BIOS-3. Soviet Union, 1972 - 1977. Fully successful, several missions. 

Sealed volume - 315 m2, crew -3 persons. There were 4 rooms: 

Living room for 3 persons

Second room - Chlorella algae for CO2 to O2 regeneration

Third room - special wheat with short stems. There were up to 14 ages of wheat simultaneously to provide permanent crop, and fourth room - garden with vegetables (every colonist got up to 0,4 kg of vegetables per day. 

In result of 6 month experiment full water and atmosphere closed cycle  (100%!!) was achieved, food - about 50%

Not solved: excessive biomasse utilization and reintroducing salt.

2. Biosphere-2. USA, 1991 - 1994. The biggest and most ambitious project, commonly considered as failure, but collected science information volume is immense.

Bold attempt to model natural Earth ecosystem. 12 700 m2 (1,27 hectares) of forest, desert, ocean, coral reef, plants, Animals: goats, pigs, chicken, reptiles, insects. 

There are tons of stories about two Biosphere-2 missions, how exciting experiment turned to fight for survival.

Here is 20 minute story of Jane Pointer of living 2 years and 20 minutes in Biosphere-2.

Another short movie about life in artificial ecosysteme:

Main failure factors:

Water condensation and rains lead to equilibrium breaking.

Insufficient garden sizes - they used one level gardens; it would be more effective to use hydroponic or aeroponic systems.

Low oxygen levels - in chosen soil there were too much oxygen eating microorganisms. Construction matherial (concrete and cement) reacted with oxygen.

No winds - without winds pressure tree trunks grew too fragile and fallen under own weight, which lead to complex damages.

The experiment demonstrated how complex must be CELSS design. Unfortunately, private investors refused to fund project after failures, so it is over. So sad.

3. Yuegong-1. (Lunar palace-1). 2014 - present time

Ongoing project of CELLS - Chinese laboratory. It has clearly articulated goal - building real prototype of CELLS for permanent lunar base.

Copy of BIOS-3 Soviet laboratory, but built with new technologies. Russian scientists from BIOS-3 were advisors in the project development. 

3 modules, 160 m2 with full volume of 500 m3. Water and atmosphere cycles are closed to 100%, food, including proteins - about 55%. Interesting, that main part of proteins for the crew of three provide mealworms, which are larvas of mealworm beetle (om-nom-nom ;))

 Unlike poor people from Biosphere-2, chinese crew look well fed!

So, this is all Icould find about CELLS current developments.. It seems, only Chinese program is on the road.

Of course there are experiments with plants growing on board of  ISS, but they are ofvery small scale and are just biological experiments, not CELLS.

Results of my query are very strange and disappointing: Biosphere-2 had shown how complex and fragile CELLS are. So where are new projects? Chinese will feel good on the Moon, but others?