By Jonathan Amos
Science reporter, BBC News
Hylas has some Ku capacity but operates mostly in the Ka band
The UK Hylas spacecraft, which aims to help bridge the "digital divide" by supplying space-borne broadband net access, is switching rockets.
Its owner, Avanti Communications, signed a contract on Wednesday with Arianespace to use one of its launchers - either an Ariane 5 or a Soyuz.
Hylas will provide 2Mbs net connections to rural and other areas where terrestrial broadband is unobtainable.
The satellite was due to be launched on a novel US rocket known as a Falcon 9.
However, the Falcon's launch schedule has been slipping as it prepares for the maiden and qualification flights it was supposed to make before carrying Hylas into orbit.
Avanti's chief executive, David Williams, said his broadband company had now raised the extra money needed to buy the certainty afforded by Arianespace's tried and tested - albeit more expensive - vehicles.
"We're a classic example of a scrappy British start-up company," he told BBC News.
"A couple of years ago we had very little money. It's turned out that our market was very much bigger than many of us thought and I now have a blue-chip shareholder base that is prepared to pay for the certainty and reliability of the world's best launch vehicle."
Hylas (Highly Adaptable Satellite) is a commercialised venture that emerged from a space technology programme within the European Space Agency and carries significant investment from the British government.
Its payload will automatically vary the amounts of power and bandwidth needed to match the peaks and troughs in demand for net access across its European "footprint".
The satellite is currently under construction and should be ready for launch next year.
The preparation is being shared by the UK division of EADS Astrium, Europe's largest space company, and Antrix, a commercial arm of the Indian space agency (ISRO).
The 2.7-tonne satellite will operate in the Ka radio band and deliver broadband services to some 350,000 subscribers.
A second satellite, Hylas-2, is already being planned even though the first has yet to fly. This spacecraft, for which Avanti hopes to secure the funding by the end of the year, should be able to support up to 1,000,000 customers.
And another, even bigger platform could then follow Hylas-2. Dubbed Hercules, this satellite would be capable of delivering 10Mbs (megabits per second) connections to up two million subscribers, and also some 50Mbs connections to a smaller group of people.
Hylas-1 will go into space using an Ariane 5 or Soyuz launcher from the Guiana Space Center, Europe's spaceport in French Guiana.
Jean-Yves Le Gall is the chairman and CEO of Arianespace, the company that operates Europe's launch services.
He said: "This is a success for Europe because it is a European [rocket] which is going to launch one of the most innovative European telecommunications projects."
The recent Digital Britain report reaffirmed the government's Universal Service Commitment to ensure that every home in the UK can get 2Mbps broadband by 2012.
A range of technologies, such as DSL, wireless, and fibre, will be required to do this. The report said satellites had a role to play in delivering broadband to rural and remote areas.
Avanti faces competition from the long established Eutelsat space communications company, which is planning its own digital-divide-busting Ka-band satellite for Europe, delivering 10Mbs through its Tooway service. Eutelsat says its KA-SAT is also due for launch in 2010.