Inmarsat's scientists told the BBC's Horizon programme that they had calculated the plane's most likely flight path and a "hotspot" in the southern Indian Ocean in which it most likely came down.
The flight lost contact on March 8 en route from Kuala Lumpur to Beijing with total of 239 passengers and crew on board.
Hourly pings sent by the plane were received by Inmarsat's spacecraft, leading scientists to calculate its likely path.
Australian naval vessel Ocean Shield was dispatched to investigate, but before reaching the likely site it began to detect a signal that it believed was coming from the plane's black box, Inmarsat said.
AFP