International Space Elevator Consortium
October 2023 Newsletter
In this Issue:
Editor’s Note
President’s Corner
Academic Challenge 2024 Announcement
Tether Materials
IAC Jerome Pearson Memorial Lecture
History Corner
Upcoming Events
Contact Us/Support Us
Editor's Note
Dear Fellow Space Elevator Enthusiast,
The International Space Elevator Consortium was represented along with 64 other organizations at the U.N. General Assembly Science Summit. These organizations came together to ask the U.N. to add space exploration, particularly civilian-led extraterrestrial exploration and colonization, to its existing charter on 2030 sustainability goals. The press release below outlines how space exploration is vital for expanding humanity’s knowledge of sustainable practices and technologies and for promoting hope in a shared future, and these organizations believe that 2025-30 will be crucial years for the development of these objectives. You can read the full press release below:
This is certainly exciting, and if the U.N. does accept this recommendation and add space exploration to its sustainability goals, this will be great for the entire civilian space exploration industry. I’ll follow this story and try to bring an update to you soon!
Sandee Schaeffer
Newsletter Editor
President's Corner
by Pete Swan
Becoming a Pioneer in a Technological Arena
Over the centuries, pioneers have had many different definitions. Mostly they were people going somewhere others had never been. Since the start of the 20th, and now 21st centuries, there have been other heroes – technological pioneers. How do people become recognized as pioneers in our technologically challenging arena and succeed where others fear to tread? This is a huge question with no answers. However, if we look over the last 100-plus years there are models to help identify those who made a difference. We all know their names and respect their contributions to the progress of humanity. I knew one who was very successful [at so many levels] mostly within our governmental programs over his career.
Dr. Paul G. Kaminski is a role model for many of us because what he left behind inside the organizations were management patterns that succeeded spectacularly. For this President’s Corner, I thought I would share his concepts of advancing mega-projects against all odds. Dr. Kaminski opened his speech with a quote from Graham Green, a famous 20th-century novelist, who said:
“There is always one moment in childhood when the door opens and lets the future in….”
Dr. Kaminski’s thoughts are paraphrased from a recently shared speech when he was given his latest award. He called them his 4 P’s:
The first, of course, is People. His team was “hand chosen, small in number, but unmatched in vision, leadership and dedication.” I really liked his short summary and recognized that for the space elevator development program to be successful we will need these same characteristics…. Especially the “unmatched vision.”
The second is Partnerships. His discussion on this one focused on “a common objective – fielding a revolutionary capability.” I’m not sure our challenge will be any less than many of his, but he emphasized the value of partnerships to include: “...partnerships at all levels. Partnerships between developers and operators, government and industry, modelers and testers, executive and legislative branches, and even bi-partisan cooperation between the majority and minority in Congress.” In addition, we must add international partnerships as our project is definitely global, Cislunar, and solar system-wide.
The third is Probity. Dr. Kaminski explained it as “… probity is adherence to the highest principles and ideals: honesty, integrity, uprightness, trustworthiness and dependability.” I did not know the word; however, I have experienced the value of probity and he is correct, it is essential!
The last one is Persistence. He is so perceptive – as we all know in space elevators – we have moved forward greatly while waiting for the material to catch up. Now that it is very close, we are starting the next big push to initiate testing. Our 23 years of persistence have been remarkable and against all odds; but, it has set us up for the next big push.
Yes, these four small words are remarkable keys to the future. Let us try to incorporate these into our daily lives supporting our vision for space elevator infrastructure. Our team must emphasize these four words:
People, Partnerships, Probity, and Persistence with an unmatched vision.
Pete
Academic Challenge 2024 Announcement
Space Elevator Academic Challenge 2024
Has been Initiated
Your SEAC-24 team has been active and has distributed invitations to high schools and universities around the world. If you have a student who qualifies please pass the word that there are financial rewards connected to this competition. ISEC is trying to stimulate thoughts within the global student population by having them investigate both artificial intelligence and the green road to space aspects of space elevators. Some important items to pass on are:
+ We now have sponsorship from the National Space Society
+ Go to: https://www.isec.org/academic-challenge for full information
+ Competition is three steps: abstract – paper – video with down-selects along the way.
+ Winners receive $2,000 (1st), $1,000 (2nd) & $500 (3rd) across both categories
+ Winners invited to present at the 2024 International Space Development Conference (late May) and the International Space Elevator Conference (Aug).
ISEC is pleased that we have had a great start to the competition. We would also like to thank the National Space Society [https://space.nss.org] for their continued involvement and their co-sponsorship of the annual Space Elevator Academic Challenge.
Tether Materials
by Adrian Nixon, Board Member, ISEC
Electrical conductivity in graphene laminates
As you will be aware from previous newsletter articles (August 2022 ISEC newsletter) that layers of large-scale sheets of graphene (graphene laminates) are the current best material from which a space elevator tether can be made. The material does not yet exist in large amounts; however, we do know that teams are actively working on this.
Graphene is the world’s best conductor of electricity, so could we use a graphene tether to transmit power and data? Comparing graphene and copper is instructive.
Copper is the world’s best non-precious metal electrical conductor. Graphene is at least 1.6 times more electrically conductive than copper. This might not sound like much but there is another factor to consider. Materials heat up as they conduct electricity, and this causes the material to fail. This is expressed as the breakdown current density, measured in amps per square metre (A/m2). The higher the numbers, the more power the material can transport. Figure 1 shows the comparison of the electrical properties of graphene and copper.
Figure 1. The electrical properties of graphene and copper
Graphene outperforms copper as an electrical conductor. With an electrical conductivity of 96 to copper’s 60 mega siemens per metre [1,3], graphene also has one million times the breakdown current density than copper. This means it can carry orders of magnitude more electric current before burning up [2,4].
A fascinating difference is the way the materials perform when measured in different spatial dimensions. We live in a world of three spatial dimensions, left-right; near-far; up-down, also called x, y, and z directions. Copper has the same properties no matter what the orientation of the material. This is termed isotropic.
Graphene is different. It is a two-dimensional (2D) material, and it performs differently in different dimensions. This is termed anisotropic. In the x/y direction it is highly electrically conductive, yet in the z direction it is 6,400 times less electrically conductive [5]. Figure 2 shows this difference.
Figure 2. The anisotropic electrical properties of graphene laminate
This anisotropy means that a tether made from graphene laminate could perform very well as a power cable. Electrical current injected at one end can be extracted from the other end, or the sides. However, this also means that it will be difficult to extract electrical power from the large exposed flat surface (basal plane). So, powering a moving climber from the tether could be quite a challenge.
We know that to make a tether, teams must work on making graphene in continuous lengths. However, getting funding to do this is proving difficult for companies working in this field because the returns on investment are much longer term than private equity sources are used to supporting. Using graphene wire ribbons for power and data cabling could be a way to gain funding in shorter timescales while developing the technology to make a full-scale tether.
We know that it is possible, in principle, to change the bonding of the carbon atoms in graphene from sp2, which is electrically conductive, to sp3 which is electrically insulating. This opens the possibility of creating long lengths of electrically conductive material with contacts at either end as shown in figure 3.
Figure 3. Graphene laminate wire ribbon for power and data cabling
Sealing the sides of a graphene wire ribbon could make a very attractive power cable for long distance power transmission. Graphene has a quarter of the mass density of copper. It is also chemically inert in ambient conditions; it won’t rot or rust. Graphene has also been found to be an excellent carrier of electrical signals. High frequency currents can be transmitted with almost no energy loss along graphene [6]. This would make graphene laminate wire ribbon very attractive for secure data communications.
There is another reason that graphene laminate wire ribbons would be very attractive soon. We face a dilemma caused by the transition from fossil fuels to a more sustainable energy future. We already need vast amount of copper for the power transmission and data cabling needed for our homes, workplaces, and vehicles.
Consider the Chuquicamata copper mine in Chile. It is one of the largest in the world, 4.5 kilometres long, 3.5 kilometres wide and with a depth of 850 metres (Figure 4). A new book, Material World: A Substantial Story of Our Past and Future, points out that to satisfy our future demand for copper, even with recycling, will require three new mines like this every year. The copper reserves exist to meet this need but the environmental impact of extracting this much material will rapidly become socially unacceptable [7].
Figure 4. The Chuquicamata copper mine in Chile
Graphene laminate wire ribbons offer a way out of the copper dilemma. Making graphene laminate in continuous lengths uses carbon containing feedstocks and locks up greenhouse gases while making a very useful high technology product.
Making the space elevator a reality will require us to engage with investors with profitable shorter-term solutions that generate returns on investment that funders will support. Making graphene laminate wires could be one of these breakthrough technologies. The manufacturing process for high-capacity power wire ribbons will be the same as that for the space elevator tether.
References:
1. Matula, R.A. (1979). Electrical resistivity of copper, gold, palladium, and silver. Journal of Physical and Chemical Reference Data, 8(4), pp.1147–1298. doi: https://doi.org/10.1063/1.555614.
2. Resistance Welding Manufacturing Alliance (2003). Resistance Welding Manual (4th ed.). Resistance Welding Manufacturing Alliance. pp. 18–12. ISBN 978-0-9624382-0-2.
3. Anon (2010). Scientific Background on the Nobel Prize in Physics 2010: Graphene. [online] www.nobelprize.org. Sweden: The Royal Swedish Academy of Sciences. Available at: https://www.nobelprize.org/uploads/2018/06/advanced-physicsprize2010.pdf.
4. Murali, R., Yang, Y., Brenner, K., Beck, T. and Meindl, J.D. (2009). Breakdown current density of graphene nanoribbons. Applied Physics Letters, 94(24), p.243114. doi: https://doi.org/10.1063/1.3147183.
5. Tsang, D.Z, and M.S Dresselhaus. “The C-Axis Electrical Conductivity of Kish Graphite.” Carbon, vol. 14, no. 1, 1976, pp. 43–46, https://doi.org/10.1016/0008-6223(76)90081-6. Accessed 24 Sep. 2023.
6. Awan, S.A., Lombardo, A., Colli, A., Privitera, G., Kulmala, T.S., Kivioja, J., Mikito Koshino and Ferrari, A.C. (2016). Transport conductivity of graphene at RF and microwave frequencies. 2D materials, 3(1), pp.015010–015010. doi: https://doi.org/10.1088/2053-1583/3/1/015010.
7. Conway, E. (2023). Material World. Random House, pp.251–290.
Jerome Pearson Memorial Lecture
This year’s “Jerome Pearson Memorial Lecture” at the International Astronautical Congress in Baku was given by our ISEC leader in tether climbers – Peter Robinson. The title of this talk was, “Research Characteristics of a Permanent Space Access Transportation Infrastructure.” He helped lead the presentations and discussions in the technical session “Modern Day Space Elevator Customer Design Drivers” on Tuesday, 3 October 2023. This talk was important to ISEC in many ways, principally with the recognition that Jerome was instrumental in the development of Space Elevators with the “first paper” at the engineering level proposing the concept (at the IAC in 1975). In addition, this provided recognition that development is progressing towards an architecture that can enable so many future missions, almost impossible by rockets. He also had a presentation for his principal paper entitled “The Space Elevator Payload Journey beyond GEO: Climber Concept and Options.”
Look for a write-up in next month’s newsletter!
History Corner
by AJ Burke, ISEC Senior Systems Engineer / IEEE Life Senior Member
NASA Space Elevator Games Powered Beam Climber
National Space Society Team
I had the opportunity to participate in a NASA Centennial Challenge Competition called Elevator:2010 [Ref: https://en.wikipedia.org/wiki/Elevator:2010] from 2005-2010. This was part of an industry and academic team that competed in the annual competition for climbers, ribbons, and power-beaming systems that were operated by a partnership between NASA and the Spaceward Foundation during that time. After downloading the Version 0.92 “rulebook” from Spaceward Foundation (April 2005), contacting the team and subsequent attempts to get the initial team members together in person at the 2005 National Space Society (NSS) International Space Development Conference (ISDC) in Washington, DC, the core team decided to start a Yahoo email group to distribute email chains to discuss the design and testing of various climber ideas. Back then, the primary power source for the climber competition was first planned as a group of 135 mirrors in direct desert sunlight and then a 10-kilowatt Xenon spotlight setup to put photons on the solar array using the concepts in the Edwards Space Elevator book (https://www.amazon.com/Space-Elevator-Bradley-Edwards-Ph-D/dp/B0B3JD9ZZW/). There were even a couple of teams using Stirling Heat Engines in the initial competition (https://en.wikipedia.org/wiki/Stirling_engine).
Eventually, some of the team did attend an in-person technical conference in Washington DC (Sep 2005) at the “International Study of Robotics” conference sponsored by National Science Foundation, NASA, and the National Institute of Biomedical Imaging and Bioengineering in the Fall of that first year (https://web.archive.org/web/20051224025458/http://www.wtec.org/robotics/). There I met one of the principal engineers for the NSS Team that I had been corresponding with on a design model via the email group on the idea of a team to compete in the Spaceward Foundation series of events. Early in the formation of the team, Larry Bartoszek, the current ISEC Design and Engineering Director (https://isec.org/who-we-are) was in these discussions, but eventually, he had to drop out at that time in 2005-2006 due to other commitments. I mention this because Larry’s pinched wheel climber design was eventually the technique that most of the teams used throughout the Elevator:2010 competitions and in the subsequent 2-year study “The Climber-Tether Interface of the Space Elevator” (https://isec.org/studies/#ClimberTetherInterface).
As a member of the new National Space Society (NSS) Team #123, which was the result of the merger of 2 teams in the NASA competition – Team #133, aka “Starclimber,” and the original NSS Team #123 (Ref: https://ajbieee.wordpress.com/2013/03/02/20-dec-2005-email-proposing-merger-of-nss-and-starclimber-team/) we continued development for the 2008 competition after foregoing the 2006 event. The former Team #133 was in the 2006 competition using the concept of a heat engine or Stirling Engine mentioned above [Ref: https://www.latimes.com/archives/la-xpm-2006-oct-19-sci-xprize19-story.html]. The NSS Team #123 benefited from Team #133’s work and continued with a dual power philosophy developing both a solar TPV and heat engine power source but did not get to compete in 2008 as the merged team. However, a significant amount of development was completed as described in the following text based on the requirements as they were understood at that time.
The power source for the 2008 competition changed from the idea of the 135 mirrors in direct sunlight in Las Cruces, New Mexico range in 2006 and an eventual 10-kilowatt spotlight used in some demonstration events (MIT event) to an 8-kilowatt 1030-nm focused infrared laser striking thermophotovoltaic (TPV) cells to convert the light energy to electricity or heat.
8 KW laser beam spreader test
The laser beam must be expanded and collimated to provide a tight beam at up to 1 km of range. The optics system must accept the 8kw laser beam without overheating or suffering other damage for at least 1000 seconds per run while transmitting at least 80% of input beam to output. Optics system must also maintain a beam diameter at the climber of between 40 and 60 cm from 50 meter to 1,000 meter of range while complying with ANSI Z136.1 (2007) Laser Safety Guidelines.
Since the laser tracking system is designed to hold the 8 KW laser beam on-target without allowing the beam to spread beyond 60 cm at a range of 1 km, this allows the laser beam to maintain targeting on the climber as it ascends the cable, which sways due to wind and vibration. The climber can then continuously move at up to 10 m/s upward and/or 5m/s horizontally due to sway. A PC-based ground station power management subsystem interfaces with the Trumpf laser and optics rail/mirror subsystems were required and a sponsor donated Dell PC uses Peak Power Tracking (PPT) systems approach to create a non-dissipative storage capability of up to the 1% of the total energy budget, which is the limit imposed by the rules and was accomplished with a large (1000 v) ultra-lightweight supercapacitor.
A telemetry communications system was designed in the climber in conjunction with the Laser Aiming/Tracking subsystem above to monitor the thermal loading on the climber and ensure that energy was being efficiently delivered. Elements of this system included a PC-based ground station, an on-board control system to regulate the power bus from the solar array to regulated and unregulated (motors mainly) for maximum power at the workload. A motor speed controller and electric braking system were also needed.
To convert the power from the 8 KW laser, a thermo-photovoltaic array was procured but it required the construction of a lightweight heat sink to deal with waste heat from the 1,000+ seconds of 50% power (4 KW) of the beam continuously hitting it. Ultimately, the array needed to produce 150 watts of power and weigh less than 1 kg. All of these items and others like the Stirling Engine that was built but ultimately wasn’t used in the competitions after 2006 are in the photomontage of Photo 1.
Photomontage of climber robot from NSS Space Elevator Team
Further, testing of the systems and subsystems was to be accomplished using a 1000-watt spotlight (in the absence of an industrial laser to test with) on a cable treadmill to simulate the tether that was eventually capable of 1000-second runs at up to 10 m/s. Slower versions of this concept were used to test control systems at slower 1 m/s speeds. All of these items are documented on my personal blog (https://ajbieee.wordpress.com/2023/09/12/elevator2010-and-nss-starclimber-teams-update/).
Finally, publicity for the team was via a website and team members did several publicity events including a short video demo for a BBC News crew researching the competition at that time.
Ultimately, the NSS Team did not get to compete in the finals that Lasermotive won, but the effort was used by this member of that 2010-era team to complete some of the work of the ISEC 2023 study. These activities and associated research have continued all along into the 2020s with published papers and studies at the International Space Elevator Consortium (ISEC) in and around their annual conference (https://www.isec.org/studies). Other competitions continue to this day the work started in the Elevator:2010 competition, including this year’s Japanese Space Elevator Competition that was recently posted in ISEC’s August 2021 newsletter (https://www.isec.org/space-elevator-newsletter-2021-august) History Corner article.
Upcoming Events
20th Reinventing Space Conference
Sponsored by the British Interplanetary Society
https://www.bis-space.com/reinventingspace/
Theme: “The Evolving Architecture of NewSpace”
Wednesday, October 11th through Friday, October 13th, 2023
Liverpool, U.K.
42nd International Space Development Conference
Sponsored by the National Space Society
https://isdc2024.nss.org/
Thursday, May 23rd through Sunday, May 26th, 2024
Sheraton Gateway, Los Angeles, California, USA
Theme: “No Limits”
75th International Astronautical Congress
Sponsored by the International Astronautical Federation (IAF)
https://www.iafastro.org/events/iac/international-astronautical-congress-2024/
Theme: “Responsible Space for Sustainability”
Monday, October 14th through Friday, October 18th, 2024
Milan, Italy
76th International Astronautical Congress
Sponsored by the International Astronautical Federation (IAF)
Monday, September 29th through Friday, October 3rd, 2025
Sydney, Australia
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