A summary report of the Space Elevator Roadmap workshop
Examining the progress toward a Space Elevator Architecture
23 August 2014
Michael A. Fitzgerald
On the last day of the recent Space Elevator conference in Seattle, the ISEC roadmaps and architecture study leads held a workshop with the attendees of the conference. The workshop had two purposes and one key objective.
- To introduce our definition of the ISEC Space Elevator Architecture’s 5 discrete segments; Climber Segment, Tether Segment, Marine Node Segment, HQ/POC Segment and the Tether Tenants Segment.
- To seek the wisdom and advice from the attendees regarding the kind of demonstrations they would like to see to “prove” the viability of the functions within the reviewed segments AND to receive the attendee’s advice regarding the substantial success criteria the demonstrations need to match or surpass to be successful.
- To initiate the first engineering efforts along the (admittedly) long road to the engineering development of a Space Elevator.
The workshop briefer presented graphics for the 3 key segments within the SE architecture. The graphics laid out the suggested pathways leading to the next major pre-development architecture activity; the implementation planning phase. Along each of those 3 paths … a series of tests, inspections, simulations, and / or demonstrations are called for. This envisioned activity, or set of activities, is to establish technological viability and the engineering validity of the segment’s make-up.
The response from the attendees was fantastic; by substance and wisdom.
Segments discussed and reviewed
The workshop briefer presented graphics for the 3 key segments within the SE architecture. The graphics portrayed the path along which segments must move on their way to preliminary and then detailed implementation plans. For the development engineers, these implementation plans are the needed series of design efforts … to build the Space Elevator. To move toward these plans, each segment must “demonstrate” that the Space Elevator holds the necessary mature technologies and validated engineering approaches needed for the design and development phase … beyond the portrayed roadmap.
- Climber Segment
The workshop briefer presented this graphics for the Climber Segment. In the presented graphic, the Climber Segment’s path is seen as resolving 3 primary functional roles of the climber.
- Delivery of a payload LEO & GEO altitudes
- Repair of the Tether
- Delivery of payloads above GEO
For each of these three primary roles the workshop offered that a test and demonstration taxonomy for 8 required functions was needed; structure, gripping, the motor, the brakes, power above 40 Km altitude, power below 40 Km altitude, a protective box for traversing the lower 40 Km, and payload support. Obviously, the test taxonomy execution can “share” the results across the functions, but it is likely that different climber configurations will require different engineering validation efforts within the test and demonstration taxonomic execution. The point is that climber configurations could vary for LEO destinations versus Climbers destined beyond GEO.
The feedback from the attendees was spectacular and is documented – in summary here. Analysis of the feedback will be more thorough over the next few months, but at first review …the attendees seek a wide range of test & demonstration events to assure our place in the competition for venture capital as well as our construct of needed, empirical engineering knowledge.
- Tether Segment
The workshop briefer presented this graphics for the Tether Segment. In the presented graphic, the Tether Segment’s path is seen as resolving the 3 primary functional manifestation of the Tether.
- Delivery of 100,000 Km of Tether to Space
- Functional knowledge of the Tether; represented in a Tether Simulation
- Tether Control and its components
For each of these three primary roles the workshop offered that a test and demonstration taxonomy for 5 required functions was needed; the tether’s dynamics, the first 5 modes of tether dynamics, perturbations from the Sun, the Earth, and the Moon, climber induced perturbations on the tether, and the hazards from debris strikes on the tether.
As with the other segments, the purpose of the workshop was to seek the wise feedback from conference attendees. For many, the Tether Segment and the set of needed tests, inspections and examinations it needs to reach readiness prior to design development , is exactly what the entire Space Elevator’s future is all about. The Tether Segment is composed of more unknown unknowns than the rest of the Architecture. A extensive campaign of test, experiments, inspections and analyses is needed. So, we asked for feedback. We got it. See the summary.
- Marine Node Segment
The workshop briefer presented this graphics for the Marine Node Segment. In the presented graphic, the Marine Node Segment’s path is seen as resolving the 4 primary elements of the Marine Node Segment.
- Floating Operations Platform
- Port Facilities
- Facilities Support Platform
- Ocean Going Vessels
For each of these four elements the workshop offered that a test and demonstration taxonomy to examine and delineate 5 required functions was needed; site location for the Marine Node, the ocean currents at that location, and the hazards from debris strikes on the tether, sea water status and makeup, Sea floor geology and seismology, weather and storms in the locale. Obviously, a great deal more must be tested and evaluated. We sought the attendee’s aid in detailing a larger and more complete set of tests needed to reach technology maturity (possibly); and mature & valid engineering approaches (most likely). We got the feedback we needed. See the summary.
The idea of letting months of hard work on you little project be open to the public for inspection … is always a little embarrassing. As it turned out I was not embarrassed; and the attendees were warm and welcoming in their feedback. It was a wonderful, humbling moment and I am proud to have been a part of it. The engineering of the ISEC Space Elevator is underway! The first step toward our destination has been taken.
The workshop feedback archive
The following is an accumulation – without comment – of the feedback received at the 23 August workshop. Repeated items were deleted.
Summary of Suggested Demonstrations
“Demonstrations” should include a range of tests, inspections, analyses, simulations, and more. Some demonstrations are likely to be a sequence of test events; a taxonomy of tests.
- Marine Node
- Security process overall
- Initial attachment or reattachment
- Adverse sea state survival / rogue wave
- Node exchange (new ship)
- Spooling Demo
- Storm Demo – “Perfect Storm Demo”
- Godzilla Demo?
- Assembly demo – Payload onto climber onto tether
- Evacuation demo
- Movement demo
- Adverse weather survival
- Receipt on transfer of climber
- Strength / tension / dynamics
- Safe destruct
- Tether disposal or removal
- Maintenance and repair
- Dampen oscillators
- Lightning strikes
- Long duration exposure
- Metrology for location, state, dynamics
- Inspection Demo
- Radiation demo
- Space debris impact demo
- Torque demo
- Electrical survivability demo
- Wear and tear demo
- Simulation on the internet
- Harmonic suppression demo
- Cold demo
- Fire demo
- Electromagnetic tests of all sorts
- Tether test in the Orbital mode
- Visualization demos
- Loss of signal
- Telemetry & monitoring
- Transfer to descent
- Climb & Descend
- Adverse weather survival
- Payload deployment
- Long duration reliability
- Response to vibrations / oscillations
- Detached climber re-entry
- Diagnostics & failure modes
- Braking demo to slow
- Braking demo to be stationary
- Computer Simulations … OPS simulator
- Radiation Survivability Demos
Summary of Success Criteria
Success Criteria are not yet quantified citations of the regime of information needed as a result of the “demonstrations”. Standards will be set at the entry to next phase. Criteria is to standards, as weight is to 100 pounds.
- Marine Node
- Sea Life effects
- Environmental effects
- Keep out zone limits
- Crew safety
- Communications connectivity
- Positioning / re-positioning capabilities
- Perturbation modes
- Tether elasticity
- Extent of tether repositioning
- Manufacture defect detection
- Repair defect detection
- Extent of tether splicing
- Tether Friction limits
- In atmosphere
- Out of atmosphere
- Durability limits
- Categories not yet defined – looking for feedback!