Lori Roberts is a high school biology teacher in Muscle
Shoals, Alabama. Lori is a leader in ocean education and is a graduate
of National Geographic Education’s two-year professional development
program, the National Teacher Leadership Academy.
James Cameron is obviously not claustrophobic. As the pilot and only crewmember of DEEPSEA CHALLENGER, he will be working in a very small space at the bottom of the Mariana Trench.
Cameron is an avid explorer with over 70 submersible dives to his credit. While aboard the DEEPSEA CHALLENGER submersible, Cameron was in a pilot sphere so small that he was not even able to extend his arms. Photograph by Charlie Arneson.
Cameron will sit within a sphere inside the sub. The sphere is formed externally from 6.4cm of steel. The interior compartment is 109cm in diameter and filled with electronic equipment and life support systems. Research proved that a sphere would be the best shape to withstand 16,000 pounds-per-square-inch of pressure. But how will Cameron be able to work comfortably in such cramped quarters?
Help your students to experience what he will feel with this simple lesson.
Introduce them to the sphere by showing the Sub Sphere video clip from www.deepseachallenge.com. Assign students the task of researching the
submersible’s sphere online. The sphere facts are located on the page
called The Sub; there is also an excellent diagram (pictured below). If you do not have
access to a media lab, copy the article for your students and give them a
list of questions to answer.
I had my students answer the following
• What is the internal diameter of the pilot sphere?
• Why did the designers choose this particular measurement?
• How thick is the exterior steel?
• Why did the team use a sphere instead of a cylinder?
• Describe what James Cameron will see while seated within the sphere.
• How did engineers calibrate the oxygen requirements for the pilot?
• How much O2 is available for Cameron to breathe?
• What happens to the CO2 he exhales?
• How is it possible for him to drink his own sweat in an emergency?
• What types of emergency supplies are available to him if he gets stuck at the bottom for longer than he planned?
Filmmaker and National Geographic Explorer-in-Residence James Cameron slides into the hatch of the DEEPSEA CHALLENGER submersible as he prepares for his record dive to the bottom of the Mariana Trench. The dive was part of DEEPSEA CHALLENGE, a joint scientific expedition by Cameron, the National Geographic Society and Rolex to conduct deep-ocean research. Photo by Mark Thiessen/National Geographic.
It will take Cameron almost 2 hours to descend and he plans to explore
for another 6 hours. He will be in a cramped position for a long time.
To make this concept feel real, try this activity with your kids:
• First, place students in groups of 2-3.
• Second, group members should take turns sitting with their knees
bent and their arms crossed. (It might be neat to get a box to
illustrate the sphere and have your kids use this during the activity.)
• With knees bent and arms restricted, the student can pretend to
push buttons and check valves, as if he or she were operating the sub’s
control systems. In groups with 3 students, one student can play the
role of the “control panel,” while the other keeps track of the time.
• To be fair, have each team time individuals for several minutes while in the mock position (you decide the time limit!).
• Lastly, each student should write a short summary describing how they felt.
Watch out for leg cramps! Some kids may not be physically able to
participate, so let them be the time keeper for the group. If you try
this activity with your kids, let us know how it worked for you and your