Reaction Engines Ltd (REL) of Culham, Oxfordshire, ran a series of tests on key elements of its Sabre propulsion system under the independent eye of the European Space Agency (Esa).
Esa's experts have confirmed that all the demonstration objectives. were met.
REL claims the major technical obstacle to its ideas has now been removed.
"This is a big moment; it really is quite a big step forward in propulsion," said Alan Bond, the driving force behind the Sabre engine concept..
Taking its oxygen from the air in the initial flight phase would mean Skylon could fly lighter from the outset with a higher thrust-to-weight ratio, enabling it to make a single leap to orbit, rather than using and dumping propellant stages on the ascent — as is the case with current expendable rockets.
If such a vehicle could be made to work, its reusability should transform the costs of accessing space.