In the three years since Malaysian Airlines Flight 370 disappeared with 239 people aboard, an international search team has spent some $150 million to scour tens of thousands of square miles of ocean. The effort has yielded no helpful sign of the Boeing 777, but that doesn't mean it's been a pure waste of time and money. Along with a few scraps of the jet, the search has turned up a variety of scientific advances.

Thanks to efforts made in the search, oceanographers are more familiar with the terrain far below the surface of the Indian Ocean. The deep-tissue forensic analysis of scant data from the missing plane will help guide future searches for other aircraft gone astray. Now, as well, scientists studying the movement of objects across the Earth's watery surfaces wield a far greater understanding of the variables that influence where and how fast those objects go.

That last bit of the MH370 saga started in July 2015, when a piece of the Boeing 777’s wing washed up on the island of Réunion, off Africa’s southeastern coast, more than 2,500 miles from the primary search area. Researchers from Australia’s Commonwealth Scientific and Industrial Research Organization tossed a series of six replicas of that part, called a flaperon, in the water. They matched the replicas’ behavior with their knowledge of ocean winds and currents, and made their best guess for where it would have started its journey more than 16 months earlier. The Australian Transport Safety Bureau, which is running the search, used that intel, along with other clues, to select a 46,000-square mile chunk of Indian Ocean as the likely resting place of MH370 and its passengers.

Then the search party—human spotters, drones, underwater scanners, aquatic robots, dozens of ships—trolled the zone, as they had other targeted areas for two years. They found zilch. Last summer, they put the hunt on hold and returned to shore.

Meanwhile, something about the drift modeling bothered the Australian researchers. They weren't sure the wood and metal fabrications floated in quite the same way as a real Boeing 777 flaperon. They weren't even exactly the same size and shape. They had settled for an estimate, because they didn’t have access to the real deal.

“We would have used a genuine flaperon earlier if one was available,” says David Griffin, the lead research scientist. They weren’t about to mess around with the MH370 flaperon itself, a rare bit of evidence from the crash, and Boeing didn’t have any spares available, let alone the six the researchers wanted. Parts like that are harder to come by than you might think. Most Boeing 777’s need theirs, and there aren’t many of the modern airplanes in aircraft boneyards to scavenge for parts.

French police officers carry a piece of debris known as a flaperon in Saint-Andre, Reunion Island on July 29, 2015. AP

In December, 2016, they got lucky. The US National Transportation Safety Board, working with Boeing, located an available flaperon—source undisclosed—and sent it down under. Griffin and his team rushed to validate their original work. They cut the flaperon to fit the shape of the original as found on Réunion, and dropped it in a water tank to confirm its buoyancy matched, too.

Then they sailed into the waters near southeast Tasmania, to see whether their new sample matched the movement of the replica they had used for their testing, and how any differences could call into question their original findings.

Their work has been pushing some of those boundaries forward. Metron engineer Doug Marble

The bad news: The new flaperon didn’t match the replica. It pitched over much more readily, indicating lower wind speeds than previously thought could affect its movement. Its weight balance was less symmetrical than that of the replica, suggesting drag forces in the water would send it in a different direction.

After 13 days of fresh testing, the team compiled the data and discovered that the flaperon most likely drifted both faster than the replica and up to thirty degrees to the left of the wind. That new information doesn’t actually change the current proposed search area, a roughly 10,000-square-mile zone north of the area where the searchers focused in the early days. Its value is in validating that area of focus, whereas the previous study’s location theory depended on assumptions about other oceanographic variables, specifically the possible arrival of an ocean eddy that would carry the flaperon to the south, and which may or may not have actually happened.

More broadly, the research helps advance the potential for drift analysis contributing to other applications—a technique that is perhaps surprisingly underutilized. “Accurately predicting the motion of a small object, which changes its orientation to the wind and currents over a period of seconds, drifting across an entire ocean basin over a period of months, requires an exquisite combination of models which don’t exist in an integrated form today,” says Doug Marble, a senior manager at simulation and engineering consultancy Metron. “Improved field observations and advances in computing and numerical methods have brought us large advances in environmental modeling, but there’s still work to be done. [The Australian researchers'] work has been pushing some of those boundaries forward."

Both Marble and Griffin say the potential impact of improved drift analysis can be expansive, aiding in man-overboard searches, oil spill tracing, plastic pollution, the progress of invasive species across the seas, fishery development, and coral reef management.

Whether it will actually help find MH370, however, remains to be seen. With the search currently suspended, it will likely take still more convincing research to compel the Australian government to dive back in—according to The Telegraph, Australian transport minister Darren Chester has declined to reopen the search, since “the new analysis did not appear to constitute new evidence.” But even if the aircraft is never found, the insights brought about by the researchers’ persistence will pay dividends—and possibly save lives—in the future.