Elon Musk's Hyperloop concept is inching closer to reality.
Infrastructure group AECOM will provide the first prototype tube in spring 2016 alongside SpaceX headquarters in Hawthorne, California. (Video via AECOM)
But let's back up for a minute. What the heck is hyperloop again?
"A concorde and a railgun?" Walt Mossberg asked.
"It's a cross between a concorde, a railgun and an air hockey table," Elon Musk said. (Video via The Wall Street Journal)
It's Elon Musk's vision for a people-mover that links cities like Los Angeles and San Francisco. The concorde bit — a reference to the supersonic jet — comes from the proposed high speed of the passenger capsules — 760 mph. And the railgun bit comes from the linear accelerators that get them going that fast.
For reference, Mach 1 at Earth sea level is 761 mph. When your vehicle gets going that fast, you start to risk triggering sonic booms as it pushes against the air. (Video via Leona A / CC BY 3.0, NASA)
Luckily, Hyperloop capsules would stay just a few miles an hour short of the speed of sound and ride in a low-pressure tube the whole way — the bit about the air hockey table.
The tube sits on pylons, like a monorail. It's held at roughly 1/1000th the pressure of the outside air. Each capsule uses air bearings that suspend it between .02 and .05 inches from the tube surface.
AECOM's test version will be a 6-foot-diameter steel tube, nearly a mile long. A SpaceX contest will fill it with various pods from university design entries until something sticks — or floats. (Video via SpaceX)
Teams will attend a design weekend on Jan. 29 in Texas; proving-ground tests will start in summer 2016.
This video includes music from Frenic / CC BY 3.0.