The latest attempt to drill into the Earth’s mantle is underway, reports Nature.

Earlier efforts to pierce the Earth’s crust to the Mohorovicic Discontinuity — aka the “Moho,” the boundary between the crust and the mantle — were well underway as far back as the 1960s. A venture known as “Project Mohole” involved drilling off the coast of Guadalupe, Mexico. They reached as deep as 600 feet below the seafloor — and although the work was going as intended, project management issues and Congress budget cuts eventually scuttled the undertaking by 1966.

Man has yet to make contact with the mantle.

However, a new endeavor is currently underway as the crew of the drill ship JOIDES Resolution work on a location in the Indian Ocean known as “Atlantis Bank.” A stable patch of ocean crust, the site is only 2300 feet below the water’s surface — making it a reasonably easy stretch to reach — and it is believed that there the mantle actually rises above the Moho border, another optimal amenity.

Reaching the mantle and obtaining an undisturbed sample could be a vital achievement, as it could help science better understand the early make-up of the Earth, as geophysicist Holly Given of the Scripps Institution of Oceanography in San Diego tells Smithsonian, “It would be ground-truth for what the world is made of.” Any samples ever previously found were exposed to air or water, which likely altered composition. Mankind has yet to examine an undisturbed specimen of mantle material.

According to the JOIDES Resolution’s website, the expedition is scheduled to continue until January 30, 2016, although Smithsonian has stated that as of Friday, the drilling had only reached about halfway through the crust — but a second mission has been approved, with the eventual goal of reaching the mantle potentially as distant as five years from launch.