The Malaysian Government, under intense pressure from relatives of MH370 passengers, yesterday released the Inmarsat satellite data that forms the basis of the search area for the Boeing 777 off WA.
And 80 days after it disappeared, the first phase of the tedious search for MH370 and its 239 passengers and crew will wind up today, with Ocean Shield expected to return to port after completing a search of the ocean floor within the depth limits of the Bluefin-21 underwater vehicle.
Work for the second phase is under way, with the Chinese survey ship Zhu Kezhen mapping the ocean floor in the search zone.
This is required ahead of a widening of the search by a commercial contractor using a towed side-scan sonar capable of depths of 6000m.
The main area being searched is where the first two black box pings were located on April 5.
However, the seabed drops away from 4500m to 5500m and even deeper further to the north.
Ocean Shield has searched an area of 10km around the second ping to a depth of about 4700m.
Chinese ship Haixun 01 is supporting the survey, which includes taking the survey data to Fremantle weekly for processing by Geoscience Australia.
Work continues to analyse all the information relating to the likely flight path of MH370, together with the information from the search so far.
The data from communications between satellites and MH370 will enable scientists and analysts around the globe to review the calculation used by the investigators to determine the search area.
It is expected the data will both throw up and discount theories about what happened to MH370, which disappeared on March 8.
For some time there was confusion over who could make the satellite data public. Malaysian officials told CNN this month their Government did not have the raw data.
But Inmarsat officials told CNN the company provided it to Malaysian officials "at an early stage in the search".
Earlier this month, Inmarsat senior vice-president Chris McLaughlin insisted it had "shared the information" it had and said that "it's for the investigation to decide what and when it puts it out".