Inflatable stairway to heaven

THE space elevator has long promised a cheap, green and leisurely way into orbit, but even its most optimistic proponents know the reality is decades away. Now there’s an alternative: a titanic hybrid between a bouncy castle and a Tinkertoy that can soar 15 kilometres skywards (see “Climb the inflatavator for a journey into space”). The necessary materials are there, and the inflatable structure might eventually extend to a lofty 200 kilometres. Wayward pilots, woodpeckers, high heels and other hazards aside, this could truly be several thousand springy steps for mankind.