Exploring pristine mantle beneath the ocean

Reaching Earth' s pristine mantle has been a frontier quest more than half a century in the making. Considered the most challenging endeavour in the history of Earth science, the mantle could hold clues to the origins and co-evolution of life and Earth and some of the other most compelling questions in all of science. for example,
  How far in the future will Earth remain suitable for life?
  What lies beneath the deep ocean floor?
  What are the reservoirs of energy in the mantle and their fluxes to the crust?
Now, scientists and engineers plan to achieve something never been done before-drilling into the next layer of our world, the mantle, through many kilometers of Earth's crust.
Deep understanding of the mantle is key

Since the 1950s, scientists and engineers have dreamt of crossing the terrestrial frontier to reach the mantle. The quest began in 1958 with "Project Mohole" , conceived as the equivalent in Earth science of Space science's moon shot. While it did not reach the mantle, Project Mohole cracked open the way for decades of discovery with new capabilities to retrieve and study cored samples of sediment and rock brought up from the ocean floor.
These studies have revealed insights into the chemistry of ancient oceans and Earth's past climate. They revealed the deep biosphere of microbial life surviving within the oceanic sediment and crust at temperatures and pressures previously unimagined. Since these pioneering efforts, stronger materials, new analytical technologies, and more sophisticated drilling techniques have steered the design of a new generation of scientific ocean drilling vessels. The Chikyu which will enable even greater discovery.