If he keeps this up, will he have enough air? After watching a video about spacewalks, groups of four brainstorm aspects of spacesuit design and present it to the rest of the class. Groups create mathematical models of oxygen use for two astronauts, knowing the rate of consumption and the initial tank pressures. Using the equations, groups determine whether each astronaut has enough oxygen to last the entire spacewalk and when the two astronauts will have the same amount of oxygen left.