At such speeds, temperatures outside a spaceplane can rise to more than 1, 000 degrees Celcius.

FORBES: As SpaceX Launches, Hybrid Engine May Have A Cheaper Solution?To Space Travel

The spaceplane being developed by UK billionaire Sir Richard Branson has made its first powered flight.

BBC: Science correspondent, BBC News

The engine allows a spaceplane to take off from a runway like any normal jet, and go as fast as Mac 5.5 on a jet-like engine.

FORBES: As SpaceX Launches, Hybrid Engine May Have A Cheaper Solution?To Space Travel

This concept - for those not familiar with it - is for a re-usable spaceplane that could put up to 15 tonnes into an orbit several hundred km above the Earth.

BBC: Skylon: Ending 40 years of hurt

Those of you who follow this column are always keen to hear the latest news on the British spaceplane concept, and the most recent development strikes me as being a key moment in what will be a critical few months.

BBC: Skylon: Ending 40 years of hurt

The UK Space Agency initiated a review of Skylon and as part of that assessment it asked propulsion engineering experts at the European Space Agency to run the rule over the spaceplane and, in particular, its breakthrough Sabre engine design.

BBC: Skylon: Ending 40 years of hurt

Reaction Engines is still a ways behind SpaceX: it has only a fraction of the funding and has yet to build an actual prototype of a hybrid engine, never mind the Skylon, a proposed spaceplane that it would power.

FORBES: As SpaceX Launches, Hybrid Engine May Have A Cheaper Solution?To Space Travel

Ultimately, the aim is to spur human space flight, though the officials acknowledged work on a capsule that potentially could carry astronauts or, less likely, a spaceplane with wings vaguely resembling NASA's retired space shuttles, remains at an early stage.

WSJ: Microsoft Co-Founder to Build Massive Jet for Space Launches