Inmarsat, which is based in London's Silicon Roundabout at Old Street, launched its third satellite into the atmosphere today.
The Inmarsat-5 F3 was carried into space by a rocket at 12:44pm UK time. This creates the world’s first globally available, high-speed mobile broadband service, delivered through a single provider.
"We launched our first satellite over Europe, the Middle East and Africa about a year ago; our Americas satellite comes into operation in about a week; and this third satellite, which will go operational by the end of the year, completes a global seamless network," Rupert Pearce, Inmarsat's chief exec, told BBC News earlier.
The previous launch was delayed when a Proton Breeze M rocket carrying a Mexican satellite blew up over Siberia minutes after take-off. The rocket had been of the same model as the one scheduled to deliver today's satellite, so the launch was postponed pending an investigation.
"Yes, we're about a year late, and that's very frustrating because we know our customers want this technology," Pearce said.
"But I think it's going to be very successful for us, and we've got at least a couple of years' lead on anything else that even looks like this coming to market."
The FTSE 100 firm hit headlines around the world after its technology helped track down flight MH370, the Malaysia Airlines flight that disappeared while flying from Kuala Lumpur to Beijing last year.