The recent decision to suspend the search for Malaysia Airlines Flight 370, the aircraft that vanished over the Indian Ocean on March 8, 2014, with 239 people aboard, highlights how hard it is to recover a plane once air traffic controllers have lost track of it.

The mystery of what happened to MH370 as it flew from Kuala Lumpur to Beijing has been a driving force behind innovations in aircraft tracking to prevent such an incident from happening again.

Last year, a cross-industry Aircraft Tracking Task Force—including the International Air Transport Association (IATA), the International Civil Aviation Organization (ICAO), and other organizations—issued a report with recommendations for improving global aircraft tracking. Since then, these groups have been working to improve tracking standards.

One such standard is a rule that would require airline pilots flying over the ocean to report their position by radio every 15 minutes, compared with the previous rule of 30 minutes. The new standard takes effect next year, but many airlines have already implemented the practice.

And things are likely to get more advanced in the coming years, as improved technology is added to flights. IATA Director of Flight Operations Atholl Buchan recently told the Associated Press about a few of these options.

“In a few years, new systems and technology, if adopted universally by [air traffic control providers], will allow for global surveillance coverage,” he said.

Among them, according to the AP report, are minute-by-minute tracking of planes when they’re in distress and satellite flight-tracking services that work over the ocean, a technology being built by the joint venture Aireon. The company launched the first 10 satellites into orbit last week and expects to have 100 percent coverage of the world by next year.

In a 2016 IATA blog post, Buchan noted that the association was working to find solutions to the tracking issue that minimized costs for aircraft operators, while determining “acceptable risk.”

“From the outset … one of the hopes [was] that operators would not have to outfit their aircraft with additional equipment,” Buchan said. “Most long-haul aircraft already have the necessary equipment, but, smaller narrow-body aircraft which fly limited time over water in regional operations might not be equipped for automatic position reporting.”

Meanwhile, there’s no closure in the MH370 story, and some are calling on search parties to not give up.

“Commercial planes cannot just be allowed to disappear without a trace,” said Voice370, a group that represents the families of the MH370 passengers, according to NBC News.

Flight officer Rayan Gharazeddine, shown in 2014 assisting with the search for missing flight MH370. (Reuters file photo)