For a small technology company trying to revolutionise low-cost commercial space travel, the sale of a minority stake to aerospace giant BAE Systems could turn out to be the defining moment in its quest.

Its Sabre engines for commercial air travel can go from zero to five times the speed of sound, and up to 25 times the speed of sound for space travel.

Experts believe hypersonic air travel could enable people to one day journey anywhere in the world within four hours. At Reaction Engines, based in Oxfordshire, they think this could be a reality within 10 to 15 years.

However, before last month's deal, Reaction was a highly respected research business, but with limited funding had been effectively stuck as a start-up since its foundation in 1989.