In early April, search crews picked up a series of underwater signals in the area the satellite data indicated was the likely crash site. The signals appeared to be consistent with the "pings" from aircraft black boxes, which contain flight data and cockpit voice recordings. The head of the search operation, Angus Houston, said the signals were "a most promising lead" and hopes were initially high for a breakthrough, but an intensive search by an unmanned submarine found nothing.
In an interview with CNN earlier this week, Inmarsat chief engineer Mark Dickinson said the planned release of the satellite data would not be enough for independent researchers to replicate the calculations. Some aviation experts have speculated that governments might not want to release all the data, or other needed information on the satellite system, because of commercial or national security reasons.
But Dickinson said he was highly confident of the data.
"This data has been checked, not just by Inmarsat but by many parties, who have done the same work, with the same numbers, to make sure we all got it right, checked it with other flights in the air at the same, checked it against previous flights in this aircraft," he said. "At the moment there is no reason to doubt what the data says."
Congregating in Internet chat rooms and blogs, many scientists, physicists and astronomers have been trying to replicate the math used to determine the southern route, either as an intellectual exercise or out of a belief they are helping the relatives or contributing to transparency in the investigation.
Duncan Steel, a British scientist and astronomer, said some of the data "may" explain the belief that the aircraft went south rather than north, but that a further confirmation would take a day or so. But he too was disappointed. "One can see no conceivable reason that the information could not have been released nine or 10 weeks ago. Even now, there are many, many lines of irrelevant information in those 47 pages," he said in an email.
The final "handshake" message sent to the satellite didn't coincide with the previous, hourly pings.
In a report on its website titled "Considerations on defining the search area," the Australian Transport Safety Bureau said the last message was a "logon request from the aircraft that was consistent with satellite communication equipment on the aircraft powering up following a power interruption."
It said the interruption may have been caused by fuel exhaustion, a potentially significant finding.
Given that investigators believe the plane was deliberately diverted, the role of the pilots has come under scrutiny. Much of the speculation has centered on whether the aircraft could have suffered a mechanical failure in which the pilots struggled to regain control before all on board were somehow incapacitated, or whether it was crashed deliberately.
Brummitt contributed from Hanoi, Vietnam. Associated Press writers Kristen Gelineau in Sydney and Didi Trang in Beijing contributed to this report.