The near future: tourists peer excitedly out of portholes far above the Earth, entranced by the sight of the starry blackness above and the curved blue horizon below. However, this is not a spacecraft, but a ‘near-space balloon’. It was launched from Mongolia, not Houston. And the tourists are Chinese.

Such balloons are a new ‘high frontier’. In 1958, Russia amazed the world by launching Sputnik, the first satellite. American hurriedly set up Nasa to compete in the space race and became the world’s pre-eminent space power. Satellites are vital in communications, weather monitoring, navigation and other areas. But 60 years after Sputnik high-altitude balloons are challenging them.

Balloons provide a vantage point at 30 kilometres (18.7 miles) for communications or monitoring, much closer than satellites. They cost a fraction of the price and, unlike satellites, can easily return to Earth for upgrade or repairs.

Nasa pioneered the first stratospheric balloons in the 1950s; today the agency uses them for atmospheric research, Earth observation and exploring cosmic rays. The balloons are huge – some are seven times the size of St Paul’s Cathedral – made of plastic the thickness of a sandwich and filled with helium. Their weakness is that they can only drift with the wind; the big breakthrough in recent years has been learning how to steer them.

“We’re learning a whole new area of navigation,” says Jeffrey Manber, CEO of US space company Nanoracks. “To me, what’s going on now harkens back to the great days of sailing by the stars and the winds – it’s back to the future.”

The upper atmosphere is called the stratosphere because it is ‘stratified’, divided into many different layers, with winds blowing in different directions at different altitudes. In principle, and given the necessary weather information, a balloon can go in any direction desired simply by moving to the right altitude and riding the wind.