Wreck of the RMS Titanic research. The stern section, which had previously received relatively little attention from explorers, was specifically targeted for analysis. The microbial colonies aboard "Titanic" were also a key focus of investigation. The second expedition, from 27 May – 12 June 2004, saw the return of Robert Ballard to "Titanic" nearly 20 years after he discovered it. The expedition spent 11 days on the wreck, carrying out high-resolution mapping using video and stereoscopic still images. 2005 saw two expeditions to the "Titanic". James Cameron returned for the third and last time to film "Last Mysteries of the Titanic". Another expedition searched for
Wreck of the RMS Titanic – for the Navy. The Navy commissioned Ballard and his team to carry out a month-long expedition every year for four years, to keep "Argo / Jason" in good working condition. It agreed to Ballard's proposal to use some of the time to search for "Titanic" once the Navy's objectives had been met; the search would provide an ideal opportunity to test "Argo / Jason". In 1984 the Navy sent Ballard and "Argo" to map the wrecks of the sunken nuclear submarines USS "Thresher" and USS "Scorpion", lost in the North Atlantic at depths of up to . The expedition