Hyperloop speculation – launch assist for electric aircraft

Elon Musk is planning to announce the details of his Hyperloop transport system this month. Most people are assuming that it will be a pair of tubes running 350 miles from Los Angeles to San Francisco. The tubes will have some sort of novel system to reduce air resistance. It is assumed that 700 miles of tube plus a fleet of vehicles can be constructed for a total cost of $6 billion which is one tenth of the estimated cost for high speed rail. I don’t think you could acquire the land and right-of-way to build this system for $6 billion. This budget would not pay for enough tunnels or bridges to provide a smooth journey over the hills between the two cities.

Permitting and land access will be big problems for a ground based system. Electric aviation is going to be more viable than a system requiring a right-of-way between LA and San Francisco. If hyperloop is a 600 mph ground based tube, passengers may experience uncomfortable g-forces due to the hilly terrain.

I predict that Hyperloop will be a pair of launch tubes that accelerate electric aircraft up to 600 mph using electromagnetic propulsion. The aircraft would exit the launch tube and fly with battery power to the destination. The aircraft would make a powered vertical landing with electric ducted fans. Passengers would be transferred and the aircraft would swap batteries prior to entering the launch tube for the return journey. Energy storage would be in swappable lithium batteries. Solar power at each launch tube could be used to recharge batteries and store power for night operation.

Elon has mentioned that electric aircraft can fly at higher altitudes than conventional aircraft (e.g. 70,000 feet) which makes them immune to weather. Also, the aircraft could incorporate safety measures like parachutes so they could not crash.

Two launch tubes plus a fleet of electric aircraft could be built for $6 billion. This would utilize the engineering skills at Tesla Motors and fulfill Elon’s stated goal of building an electric aircraft.

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NASA Institute of Advanced Concepts Letter

US taxpayers rest assured – your taxes will not be funding research into electric takeoff this year. The response from NASA (NIAC) is below. This is disappointing, but there are many alternative funding sources to be pursued.

All proposals that passed the above screen then received a Competitiveness evaluation, based on:
- Potential impact of the concept if fully successful.
- Technical strength, credibility, and clarity of the proposed concept and study.
Your proposal was determined to be within scope, but did not receive a sufficiently high Competitiveness rating to be invited for a Phase I Step B proposal. Specifically for your proposal 13-NIAC13A-0102, the review panel concluded that:
- The proposal would not have had a significant impact had it been successfully completed, either because the concept’s impact was not sufficiently described in your proposal or due to similar studies completed previously. Additionally, it was felt by the reviewers that your proposal was not technically strong enough. While NIAC specifically seeks out futuristic concepts, all NIAC studies must be fully technically feasible, with a clear path towards eventual implementation.

If there are similar studies completed previously by NASA, I would be interested to read them.

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Drones – The Commercial Era Begins (VLAB event)

We’ll be attending the event below at Stanford University on Tuesday evening. There are many startups looking forward to the FAA rules for commercial use of drones.


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Nobel Prize Winning Biochemist Debunks Biofuels

Nobel prize winner, Hartmut Michel, has published an article on the efficiency of biofuels. He concludes that biofuels are worse than trees for absorbing carbon dioxide and recommends to end all biofuel programs.

The rainforests possess an important role for the climate and constitute a valuable resource for novel compounds for drug discovery. With respect to the carbon footprint, it would be even much better to reforest the land used to grow energy plants, because at a 1% photosynthetic efficiency, growing trees would fix around 2.7 kg of CO2 per square meter, whereas biofuels produced with a net efficiency of 0.1% would only replace fossil fuels which would release about 0.31 kg CO2 per m2 upon combustion!

The Nonsense of Biofuels

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Elon Musk on Hyperloop: “Like a Ground Based Concorde”

Elon Musk revealed some more details about his proposed “Hyperloop” transport system that would connect Los Angeles and San Francisco. He described the system as like a “ground based Concorde”. Also, he mentioned that “rails would not be needed”. He is working on the design with aerodynamics staff from Tesla and SpaceX. Elon will publish the concept when he is confident of the feasibility of the design.

The Hyperloop discussion begins around the eighteenth minute of the interview below. A ground based Hyperloop raises some questions about land use and rights of way. California is a crowded state. It will be difficult to find an accessible contiguous route from Los Angeles to San Francisco. Local residents on the San Francisco peninsula are already complaining about the proposed high speed train that would run through their cities.


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CNC – Cheap Tether Material Derived from Wood

The US Forest Service has opened a pilot plant for manufacturing a cheap alternative to Zylon or Kevlar for high strength applications. The product is derived from wood and could be manufactured for around $10 per kilogram.

Some comparisons with existing materials are listed below.


CNCs separated from wood pulp are typically a fraction of a micron long and have a square cross-section a few nanometers on a side. Their bulk density is low at 1.6 g/cc, but they exhibit incredible strength. An elastic modulus of nearly 150 GPa, and a tensile strength of nearly 10 GPa. Here’s how its strength to compares to some better-known materials:

Material………………………Elastic Modulus…………….Tensile Strength
CNC………………………………..150 GPa………………………..7.5 GPa
Kevlar 49…………………………125 GPa………………………..3.5 GPa
Carbon fiber…………………….150 GPa………………………..3.5 GPa
Carbon nanotubes…………..300 GPa……………………….20 GPa
Stainless steel…………………200 GPa……………………….0.5 GPa
Oak……………………………………10 GPa………………………..0.1 GPa

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Two Stage Tether to Orbit Launch System – Space Elevator Conference 2012

An alternative to the space elevator that can be constructed with current materials.

Two Stage Tether to Orbit (PDF – 7 pages)

Presentation from the Space Elevator Conference, August 25, 2012.


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Two Stage Tether to Orbit Launch System

Read the paper to learn about an alternative to the space elevator that can be constructed with current materials.

Two Stage Tether to Orbit (PDF – 7 pages)

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Space Elevator Conference 2012 – Two Stage Tether to Orbit

The Space Elevator Conference will be held at the Museum of Flight in Seattle from August 25-27. The full program is at the link below. The Two Stage Tether to Orbit design will be presented at 1pm on August 25th.


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The future of mass transportation – flying cars

As California grapples with the $68 billion budget for the high speed rail project, the Dutch have introduced a prototype flying car called the PAL-V. This type of vehicle provides the ultimate in convenience. Drive out of your garage along suburban roads, and then fold out the propeller and fly to your destination above the traffic.

For the cost of the high speed rail system, the California government could purchase 100,000+ of these machines and provide them for free use by residents. A larger version would make an excellent air taxi.

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