New Horizons – The Future of Hydrometry

The spacecraft New Horizons is on schedule to get a good view of Pluto on July 14th 2015.

We should soon have some measurements that will help determine how much of the icy planet is made up of water. On board New Horizons are instruments like Ralph, Alice, Rex, and Lorri. The requirements for these devices are that they need to be small, lightweight, powerful and robust, which sounds a lot like the specifications we desire for our field instruments on earth.  There will be trickle down of these technologies for visible and infrared spectrometry and thermal mapping; UV spectrometry; Passive radiometry; and reconnaissance imaging into devices that will enable us to measure more parameters with greater reliability and resolution than ever before in our own watersheds.

There is a lot of interest in measuring water in space.

For one thing, water is the best predictor for the evolution of anything that we would recognize as life that there is. Furthermore, if we do eventually need to abandon our planet sometime in the future (say, because a big lump of space ice is on a collision course) we might want to stop by and replenish our supply 9 years into our journey (i.e. the time it took New Horizons to reach Pluto).

On board the International Space Station (ISS), astronauts have been recycling all of their water for many years with about 93% efficiency.

This seems pretty good but if you are losing 7% per cycle it won’t take too long before you might need to re-fresh the system with clean water, which on a long mission might mean stopping on Europa (a moon of Jupiter with about 3x as much water as there is on earth) or Pluto on your way out of the solar system.

Emerging technology for water recycling is already part of an integrated water management program in Singapore which includes rainwater capture, desalination and NEWater recycled water. NEWater is planned to meet up to 55% of Singapore’s future water demand. In a water-stressed future, it may be that we will only need to source water from the environment to offset the inefficiency in our water recycling program. In essence, we are already doing that but we currently need to supplement a recycling efficiency that is near 0%. Singapore’s current efficiency of 30% and the ISS efficiency of 93% are clear indications that we can do better.

Knowing how much water in our own watershed is important.

It  is also interesting to know how much water there is 7.5 billion kilometers away. The technology for measurement is different, for now, but that is changing. If we can use our knowledge of water on earth to manage it a bit better, we may be able postpone the date that we need to leave the planet to take advantage of what we are learning about water in space.

Photo credit: NASA | “Recent Measurements of Pluto and Charon Obtained by New Horizons – A view of Pluto and Charon as they would appear if placed slightly above Earth’s surface and viewed from a great distance.”

7 responses to “New Horizons – The Future of Hydrometry”

  1. I fail to see why water is essential to life that we would recognize. An easy example – a sentient AI which we are striving to develop – would not require water as an essential compound.
    To consider water in space as a resource for earth, thought must be given to if its current location removal may create unacceptable local environmental impact, how to get it to earth and how to get it onto earth’s surface free of dangerous contaminants, more or less intact and without negative climactic impact.

    • Hi Nick
      You are correct, I would recognize R2D2 and 3CPO as sentient forms of life. However, it is highly improbable that either of them would have formed by random chance by interaction of inorganic material. It is much more probable, in fact almost inevitable given enough time, that organic life would develop in the presence of enough water in a Goldilocks zone that is just the right distance from a star.

      I wasn’t really saying that we should go to Europa or Pluto to bring water back to earth. I was saying that either spot might be a welcome oasis on a journey to somewhere else. We should look after our own planet carefully so that we don’t use it up too soon and force an interstellar migration.

      My reference to a collision with a large lump of ice is another reason to learn about water in space. Expeditions like the Philae landing on comet 67P will provide valuable data that may one day help us to avoid a mass extinction event.

      The more we learn about water in space, the better we will be able to learn about, and appreciate, water on earth.

  2. Jaime Saldarriaga July 15, 2015 at 9:16 am


  3. Wow, this really sounds like Interstellar. A whole section in 2014 AGU Fall Meeting was dedicated to complementary planetology and habitability: how much this topic still remains science fiction and how much it is already science? Fascinating and a bit scaring at the same time…

  4. Stu, I know BUT clean water on earth is an increasingly precious resource such that when practical science and engineering catch up, off plant water may alleviate earth’s water scarcity. It may initially prove easier to bring exo water to earth than to plant earthlings onto habitable off planet locations. May be a bit into the future but someone has to do it.

    • Wow! This is a mind-blowing concept. My imagination went right to a giant elevator that operates like the trams in San Francisco. The energy from clean fresh exo-water pulled by gravity toward earth hooked up to a space pulley that pulls cargo from earth into low orbit. Imagine a GHG-free method of launching supplies into space that also provides unlimited fresh water. For now I will stick with science truth over science fiction but each tend to be a good predictor of the other.

  5. A platform tethered in geosynchronous orbit? Could work almost like the Grouse tram. Future tense maybe but keep this space open.

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