Robert “Skip” Penny

by David Raitt, ISEC Chief Historian

Robert “Skip” Penny passed away on 8 December 2022, and he will be well remembered for his many years on the ISEC Board as Vice-President, being co-author of several ISEC studies, and contributions at many conferences around the world with his fifty years of experience in the space arena. Former ISEC President, Ted Semon, in his Space Elevator Blog for 11 February 2011, provided a short biography https://www.spaceelevatorblog.com/?p=1465 when welcoming Skip to the ISEC Board of Directors.

Skip graduated from the US Air Force Academy in 1970 with a Bachelor of Science degree. Over his 20-year Air Force career, he held a wide range of command and staff positions in NORAD/ADCOM, Air Force Space Command, US Space Command, and Air Force Technical Applications Center, retiring as a Lieutenant Colonel. Upon retirement in 1990, he joined Motorola on the Iridium satellite program where he initially provided operations input to the early Iridium system design, including authorship of the Iridium System Operations Concept and the Control Segment Operations Concept. In 2000, he went to work for General Dynamics where he became Network and Communications Integrated Product Team Lead for the General Dynamics-Lockheed Martin GPS III System Engineering and Integration Team. Skip gained a Master of Science degree in Space Operations from the US Air Force Institute of Technology with a thesis on a computer simulation that predicted the probability of collision for the Space Shuttle using a methodology that has since been adopted by many space operators.

Skip had a long-time interest in the Space Elevator, joining ISEC around 2006/7, and being elevated to the Board in 2011 where he became Treasurer before moving up to Vice President. Skip’s initial focus with ISEC was on designing a plausible Operations Scenario for a Space Elevator system. This had not previously been done, and it was the crucial first step to satisfy one of ISEC’s goals for 2011. The idea was to come up with a cost for maintaining and operating a Space Elevator, as opposed to the costs of building it. Over time, the operational costs would certainly far exceed the initial construction costs.

Skip presented papers on topics as diverse as climber operations, space debris, and Earth ports during the space elevator sessions at a number of the yearly International Astronautical Congresses around the world and he was a co-author on several ISEC position papers and study reports including “Space Elevator Survivability--Space Debris Mitigation" (2011), "Space Elevator Concept of Operations" (2012), "Design Considerations for Space Elevator Tether Climbers" (2013), "Design Considerations of Space Elevator Architectures and Roadmaps" (2014), and "Space Elevator Earth Port" (2015). He was also a co-author of the respected International Academy of Astronautics Study Report titled "Space Elevators: An Assessment of the Technological Feasibility and the Way Forward" (2013).

Skip chose to depart ISEC in 2017 to focus on other activities, but his contributions to the Board and study reports over his ten-year association were always timely, insightful, and highly valuable. Although he maintained contact with his friends and colleagues in the ISEC community, his departure was met with genuine regret, since his camaraderie within the ISEC leadership team ensured not only successful projects, but also growth of the organization.

Editor's Note

Dear Fellow Space Elevator Enthusiast,

The last full Space Elevator Conference (SEC) was held August of 2019 at the Museum of Flight in Seattle, Washington.

COVID-19 forced us to limit our contact to online only, so in 2020 and 2021, we held special members-only webinars in place of the SEC.

In 2022, we held a 2-day virtual conference, but it still wasn’t the same as the old SEC.

This year, plans are in work for a new location. I can’t give details because I don’t have them yet, but we should have exact dates, times, and a location in time for the March newsletter! “Permanent Space Access Transportation Infrastructure” will be the theme of the event.

Psst! Lean in and I’ll let you in on a rumor...August in Chicago!

Sandee Schaeffer
Newsletter Editor

President's Corner

by Pete Swan

A Rising Tide Lifts all Boats

Recently, I thought about an old phrase that I have always appreciated. It is a saying to keep teams working together to ensure our mega-projects are successful. In fact, John F. Kennedy borrowed a slogan from a New England Council and used it often with reference to the economy, “A rising tide lifts all boats.”

We in the space community have energized the movement of humanity off planet with NASA’s Artemis program, the Chinese/Russian research station designed for the Lunar south pole, and commercial initiatives such as SpaceX towards Mars. This overall movement beyond GEO is a great example of how Dual Space Access Architecture can “lift all boats” towards our goals of becoming an inter-planetary species, raising solar power satellites to slow down climate change while providing electrical energy for both current (pun intended) and future demands, and rapidly expanding of capabilities in planetary science.

Whether we are discussing the economy or mega-project developments, the phrase expresses the remarkable concept that working together in a cooperative style allows most projects to succeed well beyond expectations. The beauty of this concept is that the current ISEC study, "Dual Space Access Architecture," has recognized this, and hopefully, leads to this conclusion: For the future movement off planet, both advanced rockets and space elevators will help the "lifting of all boats." Indeed, the parallel development of both space access methodologies will enable humanity to reach well beyond expectations much more rapidly.

Pete

Invitation to Mastodon

For Space Elevator enthusiasts who are also avid social media users, ISEC now has an account on Mastodon.  We are @isecdotorg@techhub.social. If you're a Mastodon user, then please connect with us there.

Our other social media accounts are still active, especially Linkedin. See the full list and links at https://www.isec.org/social-media or at the bottom of each newsletter.

Tether Materials

by Adrian Nixon, Board Member, ISEC

Measuring the Friction of
Graphene Super Laminate

A space elevator tether material needs to be incredibly strong and lightweight. It also needs to be gripped by a climber that can haul itself up - and control its descent. The coefficient of friction of material combinations is one key property we need to be aware of. The higher the number, the more grip we can obtain. For the purposes of this article, we will refer to the steady state coefficient of friction (µ) [1].

Friction has been a particularly important consideration for the climber-tether interface study group. One of the early tasks we set ourselves was to establish whether a climber could climb the tether given the engineering and materials assumptions we had chosen. One of the current assumptions is that the tether will be made from continuous layers of graphene that we term graphene super laminate (GSL) [2].

Simple question: What is the coefficient of friction of GSL?

The answer is not quite as straightforward as you might expect. Firstly, friction is always an emergent property of two (or more) materials. So, we need to define what the other materials are. Secondly, GSL has not been made in quantities we can use for testing at present. However, we can use data from monolayer and multilayer graphene as a good guide. Our research of the peer reviewed literature has helped us build a database of graphene material properties. Early searches of the literature produced coefficient of friction values for graphene of 0.1 to 0.15 with sapphire-graphene and graphene-graphene [3, 4].

All good so far, until we repeated the literature search and found a completely different result. Separate research teams have published work showing graphene-diamond has a coefficient of friction in the range 0.01 to 0.05 [5, 6].

Two sets of friction measurements of graphene and an order of magnitude difference between them. What is going on?

Part of the answer is the material combinations, with diamond-graphene giving the lower friction results. There is another factor at play here. The results around 0.01 were obtained with atomic force microscopes and the results around 0.1 were produced by ball and plate methods.

Does all this matter?

Yes, this is quite important because with a materials interaction coefficient of friction around 0.1 we will be able to engineer climbers to climb the tether. However, if the coefficient of friction is ten times lower around 0.01, the task becomes much, much harder.

So, which value is correct?

They both are.

This apparent paradox can be resolved if you think about the equipment used to measure the friction. The tests with diamond on graphene were performed with atomic force microscopes. As the name suggests these operate at the scale of atoms, fractions of a nanometre. The ball on plate method operates from the nanoscale through the microscale. This is good news for our engineering designs because it points to friction being closer to the higher number as the scale increases.

The current best engineering design for the climber is a set of opposing titanium wheels clamped on either side of a flat ribbon of GSL tether.

When we get samples of GSL to test at the macroscale (the scale of our everyday experience), we can test the hypothesis that the coefficient of friction for materials such as titanium wheels and a graphene tether will be at least 0.1 and possibly higher.

A final thought…

During the writing of this newsletter article, we realised that while low friction materials were described as lubricants, there was no term for high friction materials. Several searches for the antonym for ‘lubricant’ revealed nothing useful. Dr. Dennis Wright proposed the term ‘frictant’ to describe higher friction material combinations.

For our purposes we might consider a coefficient of friction around 0.1 to be the watershed below which materials could be described as lubricants and above 0.1, materials could be considered as frictants.

I would also like to thank Larry Bartoszek for his thoughtful insights into the nature of friction.

References:

  1. Scharf, T.W. and Prasad, S.V. (2012). Solid lubricants: a review. Journal of Materials Science, 48(2), pp.511–531. doi:10.1007/s10853-012-7038-2.

  2. Nixon, A. (2022). 2022 August International Space Elevator Consortium Newsletter. [online] International Space Elevator Consortium. Available at: https://www.isec.org/space-elevator-newsletter-2022-august/#tether [Accessed 23 Jan. 2023].

  3. Dwivedi, N., Ott, A.K., Sasikumar, K., Dou, C., Yeo, R.J., Narayanan, B., Sassi, U., Fazio, D.D., Soavi, G., Dutta, T., Balci, O., Shinde, S., Zhang, J., Katiyar, A.K., Keatley, P.S., Srivastava, A.K., Sankaranarayanan, S.K.R.S., Ferrari, A.C. and Bhatia, C.S. (2021). Graphene overcoats for ultra-high storage density magnetic media. Nature Communications, 12(1). doi:10.1038/s41467-021-22687-y.

  4. Zhang, Z., Du, Y., Huang, S., Meng, F., Chen, L., Xie, W., Chang, K., Zhang, C., Lu, Y., Lin, C., Li, S., Parkin, I.P. and Guo, D. (2020). Macroscale Superlubricity Enabled by Graphene‐Coated Surfaces. Advanced Science, 7(4), p.1903239. doi:10.1002/advs.201903239.

  5. Yang, L., Zhang, Q. and Diao, D. (2016). Cross-Linking-Induced Frictional Behavior of Multilayer Graphene: Origin of Friction. Tribology Letters, 62(2). doi:10.1007/s11249-016-0681-z.

LinkedIn Poll

by Peter Robinson
Engineer, ISEC

In late December 2022, LinkedIn users may have noticed a poll that I posted on the “Space Elevator Architects” group, repeated a few days later to a wider audience on the ISEC page. Here are the words that I posted:

I'm working on a paper for IAC-2023 looking at the motion of "climbers" on the journey from GEO to the Apex Anchor, but I'm thinking that they can't properly be called "climbers" as they are braking almost all the way (as above GEO the centrifugal force exceeds the gravity force).

Should they be called "descenders"? That's not really correct either as the motion is away from the Earth. Is "car" too simple? Should it be "wagon", or "cart", or something else?

Please vote below.

Climber poll graphic

After adding together the results from both polls (and removing the vote of the person who ignored instructions and voted twice!!) the tallies were...

11 for CLIMBER
3 for DESCENDER
4 for CAR

Write-in votes:
1 for CABIN
1 for ASCENSOR
1 for SPIDER/CRAWLER
1 for CONVEYOR
1 for THE TRUCKULATOR
1 for GONDOLA

Thank you to everyone who voted, your input is much appreciated.

This means the 'Climber' that ascends from Earth to GEO will continue to be called a 'Climber' as it continues the journey to the Apex Anchor, even though it will have brakes applied almost all the way. It will need some minor modifications, but that's the subject of my paper later in 2023!

Peter

History Corner

by David Raitt

Jerome Pearson Memorial Lectures

Jerome Pearson, space pioneer, co-inventor of the space elevator and stalwart of the ISEC History Committee passed away almost two years ago. A tribute to him appeared in the ISEC Newsletter for March 2021 (https://www.isec.org/space-elevator-newsletter-2021-march/#pearson), but his memory has been invoked in perpetuity with the Jerome Pearson Memorial Lecture to be given each year at the International Astronautical Congress (IAC) within the space elevator sessions. Jerome attended and presented seminal papers on space elevators at various IACs long before there were dedicated sessions on the topic. The very first dedicated space elevator session at the IAC was organized by Dr. Peter Swan and Dr. David Raitt, taking place in October of 2004 in Vancouver, Canada, where Jerome gave a paper on his ideas for a lunar space elevator. Later, at the 2006 IAC in Valencia, Spain, he talked about the real history of the space elevator and who deserved credit for the early concepts. Jerome regularly contributed to the IAC space elevator technical sessions over the years and it is thus fitting that this Lecture Series honours him in this way. In August 2022, the relevant authorities within the International Academy of Astronautics agreed that the Keynote Speech for the space elevator technical session would henceforth be entitled the “Jerome Pearson Memorial Lecture.”

Accordingly, the first Jerome Pearson Memorial Lecture was given by Dr Peter Swan, President of ISEC, during the 73rd IAC in Paris, France from 18-22 September 2022 within the D4.3 Technical Session of the 20th IAA Symposium on Visions and Strategies for the Future. Entitled “Jerome Pearson Memorial Lecture—Space Elevators as a Transformational Leap for Human Movement Off-Planet” the paper was co-authored by Peter Swan, Cathy Swan and Michael Fitzgerald. Using Mars as an example, the Memorial Lecture delivered by Dr. Swan discussed how space elevators would be a transformational game changer by illuminating seven transformational strengths of the Space Elevator Transportation System (SETS). These include daily, routine, safe, and inexpensive access to space; transforming the economics towards an infrastructure with access to more valuable, lucrative, stable and reliable investments; massive movement (30,000 tonnes/yr vs. approximately 26,000 tonnes over 65 years by rockets); establishing a Green Road to Space to ensure environmentally neutral operations; high velocity (starting at 7.76 km/sec at 100,000 km altitude) enabling rapid transits; reduction of the need for rocket fairing design limitations; and assembly at the top of the Gravity Well. The conclusion is that the implementation of Space Elevator Transportation Systems around the world will enable remarkable capabilities to move cargo massively and routinely (in partnership with rockets), thus transforming the future of space activities.

We look forward to the next Jerome Pearson Memorial Lecture in 2023.

Perspective of Space Elevators—2023

The next three months will have segments of an overall look at Space Elevators as we see them in the spring of 2023. This perspective should help us explain our remarkable concept to the many while helping us understand the complexity of our challenges. The first of three parts will be:

Space Elevator Perspective I:
Humanity Demands Space Elevators, NOW!

From climate crisis to the desire to move off planet, future demands are extraordinary. To stop global warming and ensure humanity has sufficient energy for future generations, Space Solar Power must be immediately initiated. Approximately five hundred 3,000 ton satellites at Geosynchronous Orbit to support 12% of the global baseline electrical need, replacing coal burning plants by 2050. In addition, communities off-planet need 1,000,000 tonnes beyond GEO. To reach these numbers using rockets (at less than 2% delivery statistics—and 20 to 50 tonnes capability to GEO) something like three launches a day is expected. This exorbitant demand for rockets—burning fuel in our atmosphere—would be hazardous to the environment. When putting this all together, Space Elevators’ capabilities will be mandatory for the next step into the future. We must build upon the concept of dual space access strategy combining the strengths of both advanced rockets and space elevators.

A first step into our future must be to build Space Elevators. A leap into this bright future for humanity by using individual launches alone is counterproductive. There must be a permanent transportation infrastructure that can move massive logistics to GEO and beyond with environmentally-friendly operations. This can be accomplished by starting with the Initial Operational Capability of Space Elevators at 30,000 tonnes per year to GEO and beyond (estimate 2037) growing to the Full Operational Capability of 170,000 tonnes per year (estimate 2047). Rockets cannot grow to this capability without damaging our atmosphere. The rocket equation is a killer—even with reusability, frequent launches, and low costs.

Space Elevator Supportive Elements

As shown in the figure, the overall perspective consists of six features: Transformative Characteristics, Green Road to Space, Massive Movement of Cargo, Modern Day space Elevator, the Galactic Harbour structure, and maybe the most important aspect...Permanent Transportation Infrastructure. All this based upon the concept of Dual Space Access Architecture combining the strengths of advanced rockets and space elevators.

Our future is in the hands of Space Elevator enthusiasts.

Pete Swan

A Chat With an AI

by Peter Robinson with assistance from ChatGBT

Have you tried the new 'ChatGBT' AI chatbot? When asked, “When will a Space Elevator be built?” its response was:

     "It is difficult to predict when a space elevator, a hypothetical structure designed to transport people and cargo from the surface of the Earth to outer space, will be built. While the concept of a space elevator has been around for several decades and has been proposed as a potentially more efficient and cost-effective means of accessing space compared to traditional rocket-based launch systems, there are still many technical and logistical challenges that must be overcome before a space elevator could be constructed.

     "One of the main challenges is developing materials that are strong enough to support the weight of the elevator's cable, which would have to extend from the Earth's surface to a stable orbit around the planet. Another challenge is finding a suitable location for the anchor point of the elevator, as it would have to be located on the equator and be able to withstand the stresses of the cable's weight.

     "Given the numerous challenges that must be overcome, it is likely that it will be many years, if not decades, before a space elevator is built. Some experts believe that it may not be possible to build a space elevator at all, at least not with current technology."

We don't fully agree with the last sentence, but the rest is good for an AI system...though we have no plans for AI to replace the ISEC newsletter editor in the near future! if you want to try it yourself, click here:

https://chat.openai.com

Upcoming Events

International Space Development Conference
Sponsored by the National Space Society
https://isdc2023.nss.org/
Thursday, May 25th through Sunday, May 28th, 2023
Dallas-Frisco, Texas, USA
Theme: “A New Space Age”

Space Elevator Conference
Sponsored by the International Space Elevator Consortium
Theme: “Permanent Space Access Transportation Infrastructure”
More details coming!

74th International Astronautical Congress
Sponsored by the International Astronautical Federation (IAF)
https://www.iafastro.org/events/iac/iac-2023/
Theme: “Global Challenges and Opportunities: Give Space a Chance”
Monday, October 2nd through Friday, October 6th, 2023
Baku, Azerbaijan

75th International Astronautical Congress
Sponsored by the International Astronautical Federation (IAF)
Announcement:
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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