The search for missing Malaysia Airlines Flight 370, aka MH370, will resume Sunday in the southern Indian Ocean, almost 1,100 miles west of Australia, the Associated Press reported. The search for debris of the Boeing 777 aircraft, which disappeared from radar in March, has been on hold since May, when scientists began mapping a 23,000-square-mile area of the ocean in a bid to refine the search operations.

GO Phoenix, a vessel provided by the Malaysian government, will lead the search team. Two other ships, the Equator and the Discovery, both provided by Dutch contractor Fugro, will join the search later this month, AP reported.

“We’re cautiously optimistic: cautious because of all the technical and other challenges we’ve got, but optimistic because we’re confident in the analysis,” Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, or ATSB, the agency leading the search, told AP. “But it’s just a very big area that we’re looking at.”

The area of the Indian Ocean where the plane is believed to have crashed had been largely unmapped previously, hindering search operations in the region. Since May, two ships under the ATSB’s direction have been surveying the seabed, mapping the shape and hardness of its surface at depths ranging from 2,000 feet to four miles, as noted by the Guardian.

“The complexities surrounding the search cannot be understated. It involves vast areas of the Indian Ocean with only limited known data and aircraft flight information. While it is impossible to determine with certainty where the aircraft may have entered the water, all the available data and analysis indicates a highly probable search area close to a long but narrow arc of the southern Indian Ocean,” the ATSB said in a statement on its website.

The ships will spend as long as a year in the region, deploying video cameras, sonar and jet-fuel sensors in the search for debris.

“In all sorts of ways we’re operating towards the limits of the technology that is available,” Dolan told AP.

MH370 lost contact with air-traffic control March 8, just an hour after takeoff from Kuala Lumpur. The Boeing 777 carried 227 passengers and 12 crew members, all of whom are presumed to have died.