Investigators now look closer to solving the riddle of where missing Malaysian Airlines flight MH370 met its end. But they still have little idea why, so the search for the wreckage, and the all-important black box data recorder, goes on.
So far, cost seems to have been no object. When Hishammuddin Hussein was asked recently how much money was being spent on the search, the Malaysian defence minister stressed it had not been an issue in discussions with other countries.
"Nobody, not the Malaysian government, none of our partners, have talked about dollars and cents," he said on Saturday. "It's all about trying to find the aircraft. It did not even cross our minds."
But the longer the search continues, the more countries may have to consider their commitment to what could be a long haul – it took two years to find the black box in the case of Air France flight 447, which crashed into the Atlantic in 2009.
Paul Kane, Getty Images News
Since MH370 vanished on March 8, Malaysia has received help from more than two dozen countries, including Australia, Japan, China, the UK, New Zealand and the US.
The Pentagon has set aside $4 million, but that is expected to run out in early April. The US has not said how much more it would provide, but Rear Admiral John Kirby, Pentagon spokesman, last week said it would "stay with this as long as the Malaysians need our help".
China faces more pressure than most countries to stay the course because 153 of its nationals were on the flight, making the issue one of "political face", says Rory Medcalf, an Asia security expert at the Lowy Institute.
(Read more: Hope of breakthrough in missing jet search)
Beijing has sent 11 ships to what is known as the "southern corridor" – a search area that stretches from Malaysia to the southern Indian Ocean roughly 2,500km southwest of Perth. Two Chinese Ilyushin IL-76 transport aircraft arrived in Perth at the weekend, joining the international reconnaissance operations on Monday.
Premier Li Keqiang has said China will continue "as long as there is a glimmer of hope". But although the search has become the country's largest military operation beyond exercises, analysts say there are limits to what it would be able to do alone.
Gary Li, a Chinese military expert at IHS Maritime, said there were questions about sustainability if others cut their commitment, particularly since aircraft are more important for the search than ships.