Welcome to the November, 2017 edition of the ISEC Newsletter!

In this edition, you will find a preview of the latest ISEC Architect Note from Fitzer, an update from the Space Elevator Simulator Study, and information about the space debris problem.  We also have another write-up from one of our summer Interns. There are also some exciting upcoming Space Elevator related events around the world that you will want to check out.  Thank you for reading and lending your support in the development of Space Elevators!

As always, you will find notices of several open volunteer positions (a great way to help this project, even if you’re not a scientist or engineer) and a reminder that all ISEC reports, Yearly Reports, CLIMB Journals and the Via Ad Astra Magazine, are now available FOR FREE in electronic (pdf) format at ISEC.org. There is plenty of work to be done!

If you want to help us make a space elevator happen, JOIN ISEC and get involved!  A space elevator would truly revolutionize life on earth and open up the solar system and beyond to all of us.

Please don’t forget to LIKE US on Facebook, FOLLOW US on Twitter and enjoy the photos and videos that we’ve posted on Flickr and YouTube – all under our Social Identity of ISECdotORG.

Thank you,

Mark Dodrill

President's Corner

How bad is the space debris problem?

In 2011, ISEC produced Space Elevator Survivability – Space Debris Mitigation [pdf for free at www.isec.org] with the conclusion that space debris was NOT a showstopper.  With the proper approach by the space elevator development office, it is a manageable engineering problem.  The question in 2017 is:  will it still be the same answer after the newly announced constellations of wide-band Internet satellites reach Low Earth Orbit?  There is a remarkable movement inside the commercial space world to launch constellations of communications satellites to include:  Starlink: 4,425 + 7500 later – One Web: 720 at LEO + 1280 at MEO – Boeing: 2956 in LEO – Samsung: 4,600 – Telesat: 290 – Theia Holding: 112.  Assuming that their second stages deorbit according to mitigation plans, total new LEO satellites would be 13,103.  If we were to do the same calculations we did in 2010, we would have to have a database of tracked satellites in excess of 15,370 [old data] + 13,103 or 28,473 total objects.  [Two assumptions here: 1) we are better at deorbiting rocket stages, and 2) some cleaning will occurr during the interim years].  This essentially doubles the numbers we predicted before.  As the calculations were linear, just doubling the results works as an estimate of the problem.  The probability of collision between tracked objects and the space elevator will now be:

• For an average LEO stretch of 60 kms of tether, once every 9 years
• For the total LEO stretch [200-2000 km], PC is 7 times per year.

Remember, this is for a conjunction of tracked debris/spacecraft/rockets, with a stationary tether.  When one tosses in the ability to move the tether out of the way of tracked debris [only 7 times per year], the odds are definitely in our favor.  It once again becomes an engineering and operations problem that is achievable.

However, this short discussion is also a call for help from the space community.  We must have the ability to track smaller debris, track the larger ones more rapidly and with more accuracy, and share that data rapidly and routinely.  In addition, there are many policies/laws that should be implemented before we become operational to improve this situation.  Many of the recommendations in our study report are still valid and lead to the conclusion that the space community should:  initiate a deorbit program for all large space debris currently in LEO while ensuring that future satellites, such as the new 13,103 communications satellites, are designed for debris mitigation and deorbit [within a reasonable time – not 25 years].

Keep climbing!

Pete Swan
President, ISEC

Athena Roberts Completes 2017 ISEC Summer Internship

Ms. Roberts is an Engineering Student at Arizona State University. During her summer internship she interviewed Michael Laine with reference to the Lunar Elevator program underway and his historic activities within the space elevator community. She was also required to accomplish research and provide a short thesis on a designated topic.  She chose a topic related to future materials with space elevator potential uses.

Ms. Roberts’ Title and Executive Summary follow:

“A Comparison of Boron Nitride Nanotubes versus Carbon Nanotubes as the Primary Material for a Space Elevator Tether”

This paper discusses the pros and cons of using carbon or boron nitride nanotubes as the primary material for a space elevator tether. A conclusion is then presented for the best material based upon that information.  It begins with a summary of the problem by selecting a tether material and then goes into a brief history and overview of each material before explaining the benefits and problems with using each as a tether.  It finally concludes that boron nitride is the better material based upon a combination of adequate strength and insulator characteristics.

Communications Within the Space Elevator Architecture

Introduction

The change year – 2017 – is coming to an end and most of us in the   International Space Elevator Consortium are excited.  Our vision of a Space Elevator Architecture was presented in Seattle at the 2017 ISEC Conference.  What we see is magnificent; large regions in Space dedicated to operating the revolutionary space access transportation system.   Businesses will flourish, satellites will be repaired and refueled, power generation systems will be assembled, and interplanetary journeys will be launched.  All is wonderful.  Then we are awakened; – like that guy in the car commercial who is saved from an accident by the car’s new automatic braking system.  Jolted back to reality, we now wonder; how can we manage all these flying space objects – safely and efficiently – spread over a few zillion cubic kilometers of the great unknown.

In fact, the answer is straight forward; we communicate with all the objects in our inventory, and keep all of them under positive control.  We know where each object is, what it is doing, which way it is heading, how fast, who is nearby, what they are doing, …Wow, maybe this isn’t so straight forward!!

Click here to continue reading 

Simulating the Space Elevator

Thanks to modern software and computer technology, science and engineering projects can be modeled in great detail in virtual space.   Large parts of the design, prototyping and testing phases, which used to be performed physically in the laboratory, can now be done by simulation.

At ISEC we are applying this technology to the development of a space elevator simulator.  Long before the first tether is deployed and a climber ascends it, the physical characteristics of the space elevator will need to be studied and its motions understood.   What will the oscillations of the tether be like?  What effect will the Earth’s magnetic and radiation fields have on the motion and condition of tether and climber?   Many of the important questions about a space elevator can be answered in the near future by computer simulation, without the construction of a single piece of hardware.

At the ISEC conference in Seattle this past August, the simulation initiative was discussed with an eye to developing a state-of-the-art simulation package within one to two years of the onset of funding.  These discussions augmented the current ISEC study which is outlining the details of such a package.  Issues addressed were:

• how will the simulator be used and who will use it,
• how will the simulator evolve as developers contribute models and features,
• how will software development, maintenance and resource allocation be managed, and
• how should the software be developed and funded?

As much of the software as possible will be Open Source, that is, anyone can access the code without charge.  This will promote a large user base and encourage space elevator modelers to contribute their code.  The software must be versatile and easy to use, to the extent that even casual users could run the simulation.  Developers will use it to benchmark and test their models and one day operators will use it as a digital twin, in which real-time data from the space elevator will be fed into the simulation for diagnostics and predictions from the simulation will be used to correct space elevator motion.

It is a given that as design proceeds and needs change, the simulator software will evolve. The package must be modular and easily expanded in order to accommodate new models and features.  It must also be adaptable to user needs as users adapt to the software.

Operation and maintenance of the simulator will need to consider the changing computing landscape and take advantage of the latest developments.  It is likely that most of the computing will take place in a distributed environment such as the Cloud or arrangements like SETI@home.  Computing resources could be allocated by the purchase or donation of tokens.  Security will be an issue and users and developers will need to be vetted before receiving simulator accounts and tokens.

Development and deployment of this project will occur in stages, beginning with core code and adding modules as they become available.  The process will be guided by an ISEC steering committee which will also secure and allocate funding.  A crowd-funding project now under development will support this and other ISEC projects.   Look for it in the Spring of 2018!

Dr. Dennis Wright

Director and Chair for Studies

Upcoming Events

The British Interplanetary Society 2017 Space Elevator Symposium – 7 November 2017, London, UK
Web Site for more information: http://www.bis-space.com/2017/04/26/18868/symposium-on-space-elevators

National Space Society
International Space Development Conference
Los Angeles, CA, USA May 24-27 2018
Space Elevator Track
Web Site for more information: http://isdc.nss.org/2018/