Clear and purposeful programmatic objectives and milestones must be established, including a decision now to build a useful prototype aircraft to fly by 1995.

CENTERFORSECURITYPOLICY: Save The National Aerospace Plane

Cobra UK has branched out into the aerospace industry, and is developing a prototype lightweight aircraft seat.

BBC: Welshpool car parts firm Cobra UK plans 50 new jobs

The FAA's approval of the plan allows for limited test flights for two aircraft equipped with prototype versions of the battery fix.

CNN: Is Boeing's Dreamliner nightmare nearly over?

Concorde was an engineer's delight: it took the jet-bomber technologies that had evolved at the end of the second world war and pushed them to the frontiers of the possible, or indeed beyond the frontiers, given that the aircraft's initial prototype could not have crossed the Atlantic with a full passenger load.

ECONOMIST: Why Concorde was never the right way to speed up air travel

The current aircraft HB-SIA is effectively the prototype for the craft that will eventually be used for transoceanic flights and the round-the-world trip.

BBC: Solar Impulse plane lands in Phoenix