Speaker: Dr. Alex Ellery
Date: January 23, 2020
Dr. Alex Ellery is a Canada Research Professor in Space Robotics and Space Technology at Carleton University. His traditional interest is in space robotics, biomimetic robotics, astrobiology and allied fields. He was educated in the UK with a BSc (Hons) Physics, MSc Astronomy and PhD Astronautics and Space Engineering following which he gained experience in industry, quasi-government and academia. A few years ago, having built a planetary rover for the Canadian Space Agency, he decided to consider what space technology could do for Planet Earth and its escalating climate change problem.
Climate Change: What’s to be done?
In 2015, the global community came together and agreed to limit global temperature change to well below 2 degrees Celsius. However, in the five years since, greenhouse gas (GHG) emissions have only increased and show no signs of abatement. In fact, if thermal inertia (the lag between when these emissions are released and when the climate fully responds to them) is accounted for, our Earth has already warmed 0.8-1.25 degrees Celsius with the current level of emissions. Furthermore, projections estimate that emissions and energy consumption around the world will continue to grow due to rising standards of living.
These predictions paint a bleak picture, and Dr. Ellery argued that current dominant solutions to the escalating problem of climate change will be insufficient. For example, increasing the use of natural gas or ‘clean’ coal are unfeasible and/or impractical solutions, new renewables such as wind and solar are intermittent and have poor areal efficiencies, and nuclear power continues to face issues relating to a lack of popularity and radioactive waste. Therefore, Dr. Ellery contended that there are no terrestrial solutions to supplying the massive and growing global energy demand in a sustainable and emissions-free manner.
Rather than pursing these more traditional approaches to carbon-free energy generation, Dr. Ellery argued that humanity should look at non-terrestrial solutions, namely, solar power satellites (SPS). Besides providing a more concentrated and reliable form of energy than new renewables, this form of energy generation would move the industry off of Earth and thus relieve its stresses from Earth’s biosphere. Dr. Ellery pointed to an integrated solution: a solar shield as the short-term geoengineering solution which would treat the symptoms of climate change, and SPS as a long-term solution to the world’s growing energy demand. He pointed to the Montreal Protocol, one of the few successful international agreements relating to environmental protection, as an example of how focusing on one industry, rather than several or an entire system, can lead to a more successful outcome. Similarly, this solution would focus on only one industry: the space industry.
Proposed Solutions
As a short-term band-aid solution, Dr. Ellery suggested the use of space-based geoengineering in the form of a solar shield. There are several benefits associated with this geoengineering solution: it is fully controllable, reversible, and has no chemical interaction with the Earth’s atmosphere. Moreover, it can come in the form of one extremely large shield or a cloud of hundreds of thousands of small shields. Despite these benefits, a significant obstacle bars its implementation: the exorbitant costs associated with launching the shield(s) into space.
In a similar fashion, the proposed long-term solution, SPS, has potential but faces financial barriers. SPS could theoretically supply not only current global energy demand but could also continue to grow with demand in the years to come. Yet the cost of launching millions of satellites into space in order to generate this energy would be approximately $75 trillion, which makes this solution completely unattainable.
Thus, the barrier to implementing this integrated solution is that it’s too expensive to launch all of this technology and all of these materials into space. Ergo, the solution is to build and manufacture the technology in space. There are already efforts to build and manufacture on the moon, and Dr. Ellery believes that these efforts should be expanded to include in-situ lunar mining and utilization through self-replicating technology. The power of self-replication in-situ is that i) resources for the manufacturing of the technology and any resulting degradation of the planet would be on the moon rather than on Earth, and ii) self-replication offers an energy solution with exponential growth rather the linear growth which mass production offers.
For the self-replication of machines on the moon to be possible, the materials necessary for construction and assembly must be present on the planet. Dr. Ellery demonstrated that all necessary materials for lubricants, fuels, conductors, and other structures can be found on the moon. In fact, the only resource which would need to be imported from Earth would be salt (NaCl). The benefit of there being one input which requires importation from Earth is that humanity could halt self-replication whenever desired.
Solar shields, SPS, and self-replicating technology are not simply theoretical ideas. Dr. Ellery reviewed how these manufacturing processes and technologies are not just possible, but he is also successfully constructing them at Carleton with students. In fact, he is making significant progress on the construction of necessary technological inputs such as a Fresnel lens and 3D printed motors.
The cost of implementing this technology would still be high, but nothing compared to the costs previously discussed. Dr. Ellery predicted that the launch of a single 10-tonne self-replicating machine to the moon would cost approximately $7.5 billion. However, since it would self-replicate at an exponential rate, the cost per unit of energy generated would quickly plummet.
Dr. Ellery concluded his presentation with an overview of the multiple implications of the successful implementation of the proposed technology. Self-replication would not just provide a solution to the world’s energy and climate crisis, it would also lead to a revolution in space exploration, exponential growth in productive capacity on Earth, and it could offer a solution for the development and industrialization of developing countries. Furthermore, since self-replicating technology cannot be owned, it could democratize the means of production.
Discussion
There were a variety of questions from the audience after Dr. Ellery’s presentation. Many of these related to clarifying the functioning and viability of the technology itself while others were more interested in its implementation and possible political barriers.
Q: Are all self-replicating machines identical and performing the same function? Is there no centralized control system?
A: Yes, each unit would be identical. However, each would be a universal constructor, much like a small factory (about the size of a large vehicle) which could build almost anything. No, there would be no centralized control system.
Q: What is a realistic timeline for deployment?
A: Currently, the major barrier to this technology is funding. However, I am applying to a fund this year. If this funding is obtained, a working self-replicating machine could be ready in approximately 6 years (however it would not be flight ready yet). If we also account for the time it would take for these machines to self-replicate, the energy system could be functioning in 15 years.
Q: Once this technology is set up and functioning on the moon, what infrastructure would need to be built on Earth in order to receive the solar energy?
A: The infrastructure needed on Earth would be quite simple: two sheets of panels which would feed directly into the grid. These panels could be put anywhere and would not take up too much space. In fact, if the whole Sahara Desert was covered with these panels, it could supply the entire world with sufficient energy. Furthermore, the waves of photons coming from the SPS units would not be dangerous to wildlife flying through it or passing under it.
Q: Is anyone else doing similar work? Or is it just here at Carleton? Is there any work beyond university labs?
A: At this point in time, work on the implementation of this idea is limited to Carleton. There are some other groups working on self-replicating machines, but mostly for software. In terms of building using self-replication, there are only a few groups (including Carleton). This being said, we are the only ones pursing the self-replication of motors.
Q: What kind of political barriers do you think this technology would face?
A: My work is focused on the technical aspects and technical barriers, addressing the political barriers would be the job of others whose expertise is in policy. However, I see one barrier being the fear of runaway self-replication, which would be addressed through the necessity of importing salt (a necessary input for self-replication) and thus being able to halt the process whenever desired. Furthermore, there are luddites everywhere and it is likely that the implementation of this technology would require quite a political push.
Q: Who should own this technology? Governments or the private sector?
A: No one should own it. This technology should not and cannot be owned.
Q: If the source of power would be solar energy, would there not be an intermittency problem (i.e. at night)?
A: No, in space there is always sun. There are only two small eclipse periods during which there would be no sunlight.
Q: You predict that, if you get this funding, this technology could be implemented and functioning in 15 years. However, we need drastic climate action now. What do you need to make this happen and could it happen sooner?
A: Currently, the main barrier is funding. The technology we can develop, but we need the funds. If we had the money it would still be 6 years until we have the model. However, the 15 years is really a guess, with funding it may be possible to reduce this.
Precis completed by Silke Popescu, MA Sustainable Energy student.