Planetary Exploration, Tech Innovation, and Earth

There is increasing interest in exploiting the resources of the space environment. From the now defunct Planetary Resources to the current TransAstra, there are plans to mine asteroids and extract water for fueling spacecraft and eventually valuable metals important to the global economy. Meanwhile, Interlune has plans to extract resources, such as helium-3 from lunar regolith. It seems like space is about to become a new area of economic expansion.

It will be a while before lunar or asteroid resources become a major source of revenue for mining companies, but this focus had led to serious reactions including critical ones. One reaction is the more common question of how this benefits life on Earth. The other one is a question which has emerged more recently about whether or not humans should be altering the space environment in the first place.

The economic development of outer space has potential to be beneficial for humanity, but what about the scientific exploration of space? Does using outer space for the benefit of humanity require us to think of other planets and asteroids as just a giant resource stockpile for human production, or is seeing as an environment of intrinsic value to be explored enough to drive technical innovation that also benefits life on Earth?

Deep space missions, whether human missions or robotic, will require significant technological innovation to continue to advance space exploration. Many of these innovations have potential to help us to create a more sustainable civilization on planet Earth even though they are not being directly used for economic gain, but for pure scientific exploration.

One example that is directly applicable is the use of solar power. Solar power has been used by most space missions in the inner solar system. The farthest planet where solar panels have been used to power spacecraft is the planet Jupiter where the Juno spacecraft uses massive solar panels to power its main systems.

Most outer solar system probes have relied on the use of radioisotope thermoelectric generators (RTGs), but in a simulation of low sunlight conditions, the solar panels of the Juno spacecraft were able to still provide power even in Saturn-like levels of sunlight. This suggests that solar power could even be used farther out technology gets advanced enough.

Solar power is growing source of power on Earth as a source of clean, low cost renewable energy. The improvements needed in the efficiency of photovoltaic cells to power spacecraft on the edge of the solar system also has the potential to improve the energy efficiency of solar panels on Earth.

Another more controversial source of power is nuclear fusion. The use of nuclear fission is common in space exploration and many spacecraft including the Voyager probes relied on RTGs powered by Plutonium-238. The problem with nuclear fission is that its use is controversial due to the restrictions on the use of nuclear fission-powered devices in the Outer Space Treaty. Technically, the OST restriction only refers to nuclear weapons, but this restriction is sometimes mistakenly thought to extend to any nuclear device. Also, plutonium-238, the primary radioactive isotope used for spacecraft RTGs, is a limited resource.

Nuclear fusion, where energy is produced from fusing atoms, like in a star, instead of splitting atoms, is considered an attractive alternative if it can ever be successfully implemented because it does not produce radioactive waste and would provide significantly more energy than nuclear fission ever could.

One of the main challenges with nuclear fusion power is reaching the point where the energy produced in the fusion reaction is greater than the energy needed to sustain the fusion process in the reactor. Most models for developing a nuclear fusion reactor also would be impractical for use on a spacecraft, though there are proposed designs for fusion-powered rockets for use on crewed space missions since fusion-rockets could provide the thrust needed to get human astronauts to Mars in shorter timescales to mitigate the medical effects of long-term space travel, like radiation exposure, muscle atrophy, and bone density loss.

Fusion-powered rockets could also be used on robotic orbiters bound for the outer solar system. One of the main limitations to exploring the outer planets is rockets that lack the thrust to get spacecraft to the outer solar system in less than a few decades. A very long-term perspective is required for outer solar system planetary exploration.

Fusion-powered rockets could accelerate the exploration of important scientific targets in the outer solar system like Jupiter’s moon Europa, Saturn’s moons Titan and Enceladus, and the Uranus and Neptune systems, which have significance for understanding the origin of the planets and answering the question of whether life could have formed beyond Earth. Furthermore, Helium-3, an element relatively abundant on the Moon due to solar wind and more abundant in the atmospheres of the giant planets, could be used as an in-situ fuel source for fusion-rockets carrying astronauts to Mars or a robotic orbiter to Uranus.

Because of the need for more proficient thrust for both human and robotic exploration of the solar system, space exploration is another motivation to overcome the challenges in achieving nuclear fusion as a reliable power source. Developing nuclear fusion technology of spaceflight would also be beneficial for life on Earth. Nuclear fusion power would be a clean energy that does not produce radioactive waste products or release greenhouse gases or harmful pollution into the atmosphere. It would also produce more energy than either nuclear fission or fossil fuels. Nuclear fusion promise a future of virtually unlimited clean energy if the technical challenges can ever be overcome and the technical challenges may be overcome in space first.

Another area where space exploration can lead to benefits on Earth is more sustainable construction. If human astronauts are to travel to Mars to search for life, for example, they would need to be able to build cheap easily constructible habitats that require carrying a minimal amount of supplies with them to reduce the cost of fuel. Most ideas revolve around in-situ use Martian or Lunar regolith, depending on their intended locale. On possibility is mycotecture, the use of fungus as a building component. The use of fungus may seem strange as as construction material, but keep in mind that it is not necessarily any different from using wood, also an organic material, for construction. Furthermore, the mycotecture would not involve the use of mushroom stocks but of mycelium, the actual root structure of the fungus.

The idea is to use induce the growth of the mycelium so that it grows into a solid structure. A habitat made partially of mycelial blocks could be grown in-situ and could be self-regenerating, simplifying repairs and reducing the amount of materials that astronauts would need to take with them to construct a habitat. Cyanobacteria have also been suggested a food source for the mycelium since cyanbacteria would be cheap to grow and many are extremophiles, meaning they are especially able to survive in the harsh surface environments of the Moon and Mars. This makes mycotecture potentially promising for constructing habitats on the Moon. Mars would be trickier due to planetary protection concerns, since fungus is living and could get out of control and negatively affect possible indigenous Martian life. On the other hand, the fungus could be genetically engineered to not be able to grow outside the habitat to prevent contamination.

Developing functional mycelial architecture for astronaut outposts could also benefit Earth. On Earth, mycotecture could also be used to construct cheap temporary structures, for example to provide shelter for refugees in war zones. Mycelial architecture would carry a significantly lower carbon footprint if incorporated into regular manufacturing and construction compared to conventional materials such as plastics, steel, and concrete.

Technical innovations in energy and manufacturing are just two examples of how exploring other planets and improving life on this planet do not need to be separate and unrelated endeavors. If done right, they go hand in hand since they both involve learning to live in and appreciate a challenging environment.

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