Water in space. 3 Space exploration

But, what is ISS if not a stepping stone towards greater goals? Be it when used as a laboratory to improve our knowledge and the efficiency of our tools on Earth, or as a testbed to launch us safely and prepared to the endless horizon of vast space, ISS is the mean, not the end.

The hashtag #JourneyToMars has an obvious stop on the Moon. The current US President (let’s keep it like that), has recently signed an order to foster new missions to the Moon, which is also an European and Chinese objective (let’s not forget the Chinese Space Station, built and run by China alone, and that the first and only Quantum Physics Communications satellite is Chinese, showing the enormous power of this continuously emerging giant).

The Moon Village [4] is an European initiative to start a settlement on the Moon, for research and mining purposes (Figure 9).

Figure 9: Moon Village vision. Source: ESA

The Moon village will roughly consist of prefabricated capsules for which robots will gather Moon Dust and 3D print Solar Radiation protection. The WRM from ISS may be improved to provide water for the settlers, as well as other missions are in development on Earth to support the initiative.

As already reported by the press [Tech], two of the very water relation applications include de German DLR led EDEN ISS. Using glasshouse in a closed container that will be shipped to Antarctica in October 2017, it will prove that high plant cultivation can be an everyday reality for future lunar or orbital habitats. Container uses International Standard Payload Racks for the whole cultivation system, opening the door for easy integration with existing space infrastructure. System will also demonstrate a full mass flow for the key technologies, including structure, water, nutrients, thermal and power control.

Figure 10: EDEN ISS research facility in DLR Bremen. Source: DLR

Another of the historical human aspirations is Space Mining. The Moon Village would present an unchallenged opportunity (so far) to do so, and a mission is already being conceived: Luna Resurs or Luna 27.

Figure 11: Luna Resurs lander conception. Source : ESA

Conceived as a joint Russian-European programme, a planned joint Russian-European lunar lander that is scheduled to be launched in 2023. Most notable European contributions would include European precision navigation system dubbed PILOT and an instrument package PROSPECT that will be capable of drilling up to 2 meters beneath the surface, making it the first, true in-situ prospecting for lunar volatiles – the key to mining water of the moon.

Figure 12: PROSPECT drilling and sampling targets. Source: European Space Agency

One more interesting thing for the reader, could be than she/him could become an Analog Astronaut [5], basically testing systems and equipment in extreme Earth conditions, similar to those found in other celestial bodies.

Many other examples of cooperation and involvement of water for Space Exploration can be found in current on-going and foreseen agencies and private projects.

Satellites as tools for society

When it comes to satellite missions, water has been seeked both for human resourcing and survival in the Solar System and Exoplanets, or to understand the origin of life.

For the first cause, it may be worth looking into the JUICE missions ADS is developing for ESA, to the Icy Moons of Jupiter, Europa, Ganymede and Callisto [6] within the habitable zone, that which would make life as we know it possible on an alien planetary body. The habitable zone is defined by the distance to the planet’s sun and its temperature, so that liquid water could exist on its surface at an acceptable atmospheric pressure [7].

Figure 13: Habitable Zone criteria. Source: Wikipedia

For the latter type of interstellar water research, which provides clues about the origin of life and of the Universe, a good recent example is the Rosetta mission [8] to comet 67P aka Churyumov-Gerasimenko (catchier? For different tastes, we have the colors).

Figure 14: Comet Churyumov-Gerasimenko as seen by Rosetta. Source: ESA

The Ambition (see the video in Youtoube featuring a Game of Thrones star) endeavor, had incredibly difficult technical problems to solve, including changing its target comet, or hibernating the spacecraft for 31 months [9]. We encourage the reader to learn as much as possible about this notoriously fascinating adventure, but back to our discussion, Rosetta managed to measure the water production rate on the comet during two years [10] thanks to the instrument ROSINA [11][12].

Figure 15: Comer 67P’s water production over two years. Source: Kenneth C. Hansen of the University of Michigan [13]

Figure 16: Cycle of water ice at comet 67P. Source: ESA

The combination of all instruments shows an overall increase of the production of water, from a few tens of thousands of kg per day when Rosetta first reached the comet, in August 2014, to almost 100,000,000 kg per day around perihelion, the closest point to the Sun along the comet’s orbit, in August 2015. In addition, ROSINA data show that the peak in water production is followed by a rather steep decrease in the months following perihelion.

As for the water cycle, the team studied a set of data taken in September 2014, concentrating on a one square km region on the comet’s neck. At the time, the comet was about 500 million km from the Sun and the neck was one of the most active areas. As the comet rotates, taking just over 12 hours to complete a full revolution, the various regions undergo different illumination.

The team found [6] a tell-tale signature of water ice in the spectra of the study region, but only when certain portions were cast in shadow. Conversely, when the Sun was shining on these regions, the ice was gone. This indicates a cyclical behavior of water ice during each comet rotation

The data suggest that water ice on and a few centimetres below the surface ‘sublimates’ when illuminated by sunlight, turning it into gas that then flows away from the comet. Then, as the comet rotates and the same region falls into darkness, the surface rapidly cools again.

Context of the article

On November 23th, Diego Pozo, a Spanish space engineer, offered to the Young Water Professionals network a fantastic webinar about “Water in Space”.

In this series of 4 articles Diego explains us the content of his webinar for the people who couldn’t assist and for the not YWP members. Was a great webinar and is a great series of articles, so, in the name of all YWP’s all over the world, thank you Diego!!

You can read the previous chapters here

Water in space. 1 Experiments in micro gravity

Water in space. 2 Water and wastewater

Next article

Water in space. 4 Technology and climate monitoring


  1. Status of ISS Water Management and Recovery; L. carter, C. brown, N. Orozco, NASA Marshall Space Flight Center, for the American Institute of Aeronautics and Astronautics
  2. Upgrades to the ISS Water Recovery System; M. Pruitt, L. Carter, R. M. Bagdigian and M. J.. Kayatin, NASA Marshall Space Flight Center, for the  45th International Conference on Environmental Systems, 2015
  3. NASA Science: Water on the Space Station. Link: 
  4. ESA’s Moon Village article. Link:
  5. Austrian Space Forum for analog Astronauts. Link:
  6. ESA’s JUICE. Link: 
  7. Exoplanets list within the habitable zone in Wikipedia. Link: ]; as well as the quest for Exoplanets, link:
  8. ESA’s Rosetta main website. Link:
  9. Rosetta wakes up from hibernation. Link: 
  10. Rosetta unveils comet’s water cycle. Link: 
  11. ROSINA instrument and comet’s water cycle. Link:
  12. ROSINA instrument website. Link:
  13. Evolution of water production of 67P/Churyumov–Gerasimenko: an empirical model and a multi-instrument study; various authors; September 2016; Monthly Notices of the Royal Astronomical Society, Volume 462, Issue Suppl_1, 16 November 2016, Pages S491–S506. Link:
  14. GSA website. Link: