Elon Musk is an engineer and entrepreneur. From early innovation and success in internet technology, as co-founder of PayPal, to space exploration, affordable electric vehicles and clean energy services, his ambition is to solve environmental, social and economic challenges.

His latest idea may be the most ambitious of all.

The Hyperloop sounds like science fiction, but Musk envisions a high-speed transportation system that would be a “cross between a Concorde and a railgun and an air hockey table.”

Travelling through pneumatic tubes, the system would permit travel from Los Angeles to San Francisco in less than 30 minutes, or 343 miles (552 kilometres) at speeds of more than 685 miles per hour (1,102 km/h).

His interest in the idea was sparked when California announced high speed rail plans which would connect Los Angeles to San Francisco in less than two and a half hours. Not only was that ridiculously slow in his mind, but it would cost as much as $100 billion to design and build and wouldn’t be ready until at least 2028.

His tube idea — mounted either above ground or even under water — would be combined with a magnetic levitation system used on conventional bullet trains. That means no rail, no friction, no wind resistance, no chance of collisions, and insanely high speeds.

In an interview with PandoDaily, Musk said the Hyperloop could serve as the fifth pole of modern transportation alongside cars, planes, trains, and boats, while adding that because of its low energy usage and ability to avail itself of solar power, it could also generate more power than it would consume.

Musk first announced the Hyperloop in July 2012 but friends say he recently made a technological breakthrough which has brought the idea closer to reality.

The idea for a vacuum-sealed high-speed transit system is hardly new. The “vactrain” concept was first floated in the early 1910s, while a paper written by physicist R.M. Salter and published by the Rand Corporation in 1972 entitled the Very High Speed Transit System  describes something similar.

Musk’s iteration, like his immediate involvement, is still shrouded in secrecy. A company in Colarado is working on a functional prototype, called Evacuated Tube Transport which, according to Musk, is on the right track but also missing some key elements. A partnership arrangement or technology patenting agreement are therefore both a possibility.

Musk says he will reveal more about the Hyperloop concept in August.