Editor’s Note

Dear Fellow Space Elevator enthusiast,

We skipped the January newsletter due to the holidays and then February’s newsletter was dedicated to Yuri Artsutanov so we have a lot of articles to catch up on this month!

In this edition:

Our Fearless leader, Pete Swan, will tell us about upcoming conferences and the summer internship program.

John Knapman will talk about more features to consider for a multi-stage elevator, he will tell more about the mini-workshops from last year Space Elevator Conference, and talk about graphene. What is graphene? So glad you asked! (See below!)

Peter Robinson will give us his thoughts on reliability of the climbers and how to stop, brake, and possibly descend in case of emergency (or eject!) Important things to consider.

Our Chief Architect, Fitzer, is not taking a break, nor is he late in submission; his Architectural Note #24 has so much compelling information that we plan to submit it as a mid-month extra edition of the newsletter. Please stand by…

Have you noticed more Tweets about ISEC lately? We have a tech-savvy (or at least Tweet-savvy) member who has been posting lately! Thanks, Peter Robinson for keeping our Twitter followers up-to-date on the latest!

Thank you for your continued support of the International Space Elevator Consortium!

Sandee Schaeffer
Newsletter Editor

President's Corner

by Pete Swan

Conferences in Washington DC

ISEC will be speaking at both Washington DC conferences of interest while expanding our message to the public and "players" in space.

  • International Space Development Conference, National Space Society, Arlington Virginia, June 6-9, 2019 https://isdc2019.nss.org

  • International Astronautical Congress, International Astronautical Federation, Washington, DC, Oct 21-25 https://www.iac2019.org

These two conferences will be recognizing 50 years since the remarkable achievement of walking on the Moon. The history between then and now, while projecting towards the future with global growth of off-planet activities, will be their themes. The progress in the space world, over the last 60 years, has been remarkable while bringing huge benefits to humanity around the globe. The future seems to promise far more excitement and achievements. The ISEC needs to ensure we are recognized as future players in this revolutionary movement off-planet. As such, we will have papers and presentations reflecting the last ten years' successes (ISEC was formed in 2008). The essence of our message is reflected in the following.

  • The space elevator is closer than you think.

  • The development of space elevator technology has enabled recognition of remarkable maturity levels - Now it is time to start a program.

  • Growth to the Galactic Harbour has been initiated recognizing that there is a natural unification of the transportation infrastructure and commercial enterprises within it.

In addition to a few papers, we will have a keynote speech by our very own Jerome Pearson - ISEC member who is also co-inventor of the space elevator. To finish the space elevator track, we will have a panel moderated by "Fitzer" [Michael Fitzgerald) - our very own Space Elevator Architect.

We would love to have you join us at either of the conferences. The conferences are a "must do" with diverse topics across several days. Both conferences are essentially celebrating the 50 years since Apollo 11 while recognizing the newly born thrust by the US to return to the Moon - to Stay. We are a part of that!

Pete

Keep Climbing my Friends

Design Considerations for the Multi-stage Space Elevator

by John Knapman

To build a space elevator, the toughest challenge is to find material that is strong enough for a self-supporting tether. Building it in multiple stages is a way of overcoming that challenge. Using the concept of dynamically supported structures, it is possible to build upwards from the earth’s surface and provide supports for the lowest parts of the tether, where gravity is strongest. A five-stage design would support a tether made of carbon fiber yarn that is commercially available today. A two-stage design can support a tether with less than one-third of the strength previously thought necessary.

The study report analyses the proposal in detail, covering the underlying physics and technology, design options and prototyping work.

  • Authors: John M. Knapman, Peter Glaskowsky, Dan Gleeson, Vern Hall, Dennis Wright, Michael Fitzgerald, Peter Swan

  • Publication date: January, 2019

  • A printed copy of this Report can be purchased for $9.00 (plus shipping & handling) from lulu.com. Visiting this site also allows you to see a preview.

Climber Engineering Thoughts: Reliability and Descenders

by Peter Robinson

I'm compiling a report on Climber drive options ... but whatever drive system is selected the Reliability and Durability will be critical, given the unprecedented distance and speed requirements for an ascent from Earth to GEO.

A long engineering programme will be needed to achieve full (crewed) operation, and it is possible that the necessary climber reliability levels will not be met in the early years of (uncrewed) Space Elevator operation. This means that there will be a small risk of a climber malfunction, and action must be taken to eliminate any risk of damage to the tether: an uncontrolled descent is the worse-case scenario.

One option would be provisional of a static 'parking brake', independent of the primary drive system. This brake would be applied once the climber has coasted to a halt following a drive system shutdown, allowing repair or maintenance to be undertaken using on-board systems. At low altitudes it may be possible to dispatch a repair climber from the Earth Port with more equipment or parts, but if repair was not feasible there will need to be an emergency 'eject' system to detach the climber from the tether. The cost and weight penalty of these systems could be significant, but the alternative would be to accept the risk of a climber rendering the tether unserviceable.

Some of these safety systems could perhaps be removed after sufficient reliability growth has been achieved, at least from uncrewed climber variants.

The above 'parking brake' and 'eject' systems should be adequate for any 'ascending' Climber, meaning a climber traveling towards the GEO node from either direction. Any climber travelling away from GEO (a 'Descender') may need different features as it would not simply coast to a halt following a primary drive system failure: braking must be maintained to prevent an uncontrolled descent, meaning that some secondary dynamic braking system is required. This would probably be more complex than the static parking brake required for the 'Climber'.

The 'Descender' variant could also require an energy dissipation system in place of the power collection system needed for the Climber, raising the question of how many Descender variants will be required in the early (uncrewed) operational phases: few descents from GEO to Earth would be essential, and shipping a spacecraft from GEO to the Apex Anchor for an interplanetary slingshot may prove more costly than a launch from GEO with extra ion drive fuel.

None of the features described above represent an insurmountable engineering challenge, but will impact climber development time, mass and cost.

The Space Elevator was never going to be easy.

Mini Workshop held on Friday, 17th August 2018, during the Space Elevator Conference

by John Knapman

Here is the third and final report from the mini workshop on the subject of this year’s ISEC report, which is on the multi-stage space elevator. It addresses questions 3 and 4:

1.  What are good methods of descent?

  • Falling, gliding, retro rockets?

  • Coming down the tether?

  • What about jumping or crossing over ascending climbers?

2.  Propose good operating procedures

  • Use automation and remote control as much as possible

Methods of Descent

The discussion reached across many options and discussed the range of alternatives that seem to cover the waterfront.  Here is a list of discussion topics with short explanations:

1.  Option - only upward.  The idea is that all tether climbers only go up and the design incorporates “reuse” of all hardware at GEO and beyond.  This enables the tether to NOT DEAL WITH the tremendous energy buildup in heat of climbers coming down the tether and using brakes.  The concept recommends that all “valuable cargo” that needs to come back to the Earth (people and high value components) comes on rockets – of course the rockets had been delivered to GEO by the tether so the cost is low.

2.  Tether Braking:  The concern here is that coming down the tether creates heat as the brakes are applied.  The tremendous amount of energy in the tether climber [potential and kinetic energies] must be dissipated as the climber brakes… usually in heat.  The complexity is the amount of heat needed to be dissipated, the impact of the brakes on the tether material (repair, update of tether needed as a result), and the speed resulting from the gravitational pull.  Major studies must be accomplished once the material is identified with questions like friction coefficient?  Effectiveness of braking?  Damage to material?  Speed?  One aspect of traveling downward is that you could save energy in storage such as flywheels or large batteries.

3.  Drop off along the way:  One concept is to use braking for the low gravity region (say down to one radius high – 6378 km altitude), then release from the tether and reenter the atmosphere.  This would imply that the tether climber is designed differently going down vs going up.  The lower portion (high gravity region) would require slowing down with ablative material (?) and then parachutes to land, or aerospace shape for landing and slowing down.

4.  Use the Heat (energy):  There are many needs for energy, so take the inherent energy from entering the gravity well and transfer it to users.  Some of the potential uses are to transmit energy back to GEO operations, down to Earth’s surface, or to another tether climber or satellite. In addition, there is a suggestion to radiate energy at the proper wavelength for growth of ozone for helping our environment.

5.  Leverage Multi-Stage Space Elevator:  The problem of energy dissipation is largely solved if we have a structure up from the ground to 6,000 km or 15,000 km.  Braking on the space elevator seems reasonable if we do not go down to the heavy gravity region (possibly defined as one Earth radius altitude).

6.  Rotating Space Elevator:  If the baseline design of the space elevator is a two-strand tether that rotates then braking is not an approach. You attach to the rotating tether, go up with the tether, and release at your destination. Then downward direction payloads attach to the tether and ride down to the release location. The bottom line is: no braking required.  This is still a viable approach, it just has not been accepted as the “baseline” for a few years.

7.  Thrusters slowing down tether climbers:  To slow down inside the high gravity well has historically been accomplished by rockets.  The suggestion is that downward space elevator tether climbers have assistance to slow down - namely rocket fuel and rocket thrust.  We can have ‘cheap” fuel by getting it from the Moon or other space resource and deliver it to Apex Anchor or GEO Region.  Then the thruster is used when the speed becomes too great when going down.  This lowers the stress on the tether through braking; however, the thrust vector must NOT be in the direction of the tether – maybe up to 45 degrees out from tether (less efficient, but safer for the tether).

8.  Once in the atmosphere:  When we are going rapidly inside the atmosphere, there are methods of reducing velocity with parachutes, large drag area structures, or even wings and landing capability.

9.  Multi-Leg:  One alternative in the design of the space elevator is to have multi-base leg architecture (legs coming together at 2,000 km?)  As one goes up, there is a principal climbing leg, while the others provide stability and safety/backup.  For returning payloads, the high gravity well suggests slow trips over the last region.  So coming down a different leg would allow the tether climber to proceed slowly and lower its impact on the health of the tether material.  Slow is better with respect to heating and braking… so come down on another leg - maybe two weeks from 2,000 km.

Operating Procedures

Ongoing Operation

1.  Intermodal transfer - automated transfer of payloads from the various process climbers: surface to stage-1 climbers and from stage-1 climbers to stage-2 climbers.

2.  Climbers will remain within their designated process stages.

3.  Hand off should be automated. Cargo is moved from one vehicle suitable for atmospheric conditions to one suitable for outer space.

4.  Handoff from upper stages is merely transfer from tether to tether if it has been staggered.

5.  Humans will occasionally need to travel to the stages above the atmosphere to perform maintenance.

6.  If the cargo container is pressurized, a human could ride with the vehicle or else wear a pressurized suit.

7.  Maintenance: damage is automatically detected and there is an automated repair process. (The process is out of scope.)

Graphene: What is it and Why is it Important?

by John Knapman

What is graphene?

Graphene is an allotrope of carbon. It was first isolated from graphite as two-dimensional graphene by Andre Geim and Konstantin Novoselov in 2004.

The family of carbon allotropes and their dimensionality is represented in the following diagram:

The carbon family

Graphene is termed a two-dimensional material because the molecule of graphene is constrained to grow in the x and y directions.

Diamond and amorphous carbon can grow in the x, y and z directions and are three-dimensional materials. Carbon nanotubes can grow out from each end and are essentially one-dimensional and finally the fullerenes are zero-dimensional because the molecule cannot grow further in any direction.

Why is graphene important?

Graphene is unique because it possesses a range of superlative properties.

Graphene is 200 times stronger than steel and is the world’s best electrical and thermal conductor at normal temperatures. It is also chemically inert. However it is the strength of graphene that is of prime interest from the space elevator point of view.

We are reaching the graphene tipping point. This is a change in the dynamic from a technology push to a market pull. Graphene is beginning to move out of the laboratory and into real world applications. This is a view shared by many of the leaders in this field.

Graphene is starting to appear in commercial applications. The biggest deal of the year is probably the supply of graphene for the latest Huawei phone. Graphene is also being sold in volume into textiles for clothing. Some models of Ford cars will roll off the production lines with graphene components in 2019.

The significant industrial companies have become visible this year. The National Graphene Association’s conference brought the key global players together for the first time in Texas. Three of the top graphene companies in the world are Tier One partners at the Graphene Engineering Innovation Centre (GEIC) in Manchester, UK. They are working on graphene projects that will prevent fires, make concrete stronger and reduce CO2 emissions, make counterfeiting harder, make batteries better and improve the efficiency of aircraft design and manufacture.

Most of these projects use carbon composites containing graphene, but our greatest interest is in single crystal graphene. It has the strength we need for a space elevator, and its strength has been demonstrated on small pieces. A method of producing sheets of single crystal graphene has been developed in China using copper as a substrate. The latest idea is to use liquid metal as a substrate. This makes it much easier to pull the graphene sheets away, and it should be possible to establish a continuous production process that can produce very long, flawless sheets, eventually reaching the thousands of kilometer lengths needed.

Source: Adrian Nixon of Nixene Publishing  Limited, www.nixenepublishing.com 

Summer Internship Program

Deadline - 15 May 2019

ISEC will have an internship program this summer to stimulate research inside the space community with the purpose of improving the Body of Knowledge on space elevators.  The expectation is that the intern would work from home, putting in approximately 10 hours a week researching various components of the space elevator while working with an ISEC mentor.  The selection will be competitive with the top several gaining internships.  The details are as follows:

  • Process: Apply, be connected with the appropriate ISEC mentor, select topic of interest, conduct individual research, confer with mentor every two weeks, interview local space professional, summarize research, present to mentor/and-or at the ISEC Conference.

  • Who: This program is open to all undergraduate students. The program is best suited to Freshman and Sophomores working in a scientific or engineering field, however students from all areas of study are encouraged to apply as ISEC works on all aspects of the Space Elevator challenge from technical engineering problems to questions of Space law and economics. We will be accepting several interns for Summer 2019.

  • Where: the intern will conduct Research remotely with meetings by Skype or equivalent. The internships final meeting will either be over Skype or at the ISEC Conference.

  • What: Interns will be researching or assisting with ongoing research of one area of Space Elevator development. Areas of research include Space Elevator History, Materials Applications for Space Elevator tethers, Earth Port infrastructure, and more. Interns will report progress regularly to their mentor and produce a summary of their research, as per agreement between intern and mentor. They will present this research in person, by skype or through a video.

  • Benefit: In addition to the unique opportunity to work with leading Space Elevator researchers each intern will be awarded a $500 grant, an ISEC certificate of completion, and a letter of recommendation.

  • Key Dates:

    Application due: April 15th.

    Internship period: June 15th - August 15th.

    ISEC Conference: August - last week

To Apply:   Please submit your application and any questions to inbox@isec.org by May 15, 2019.

Your application should include your name, school, year, major [and interests], and a short summary of your interest in ISEC and why you would like to have a career in the space arena (no more than 200 words).