Introduction On July 20 1969 for the first time humans stepped out of their spacecraft and walked on the surface of another heavenly body The Apollo mission to the Moon was one of the greatest scientific scientific achievements of the twentieth century Now in the twenty first century humans are exploring Mars but how will they breathe upon arrival As early as the 1960s and 1970s the United States and the Soviet Union began studying Mars In the 1960s both nations sent spacecraft on flybys of Mars to take photographs and gather information from orbit In 1965 NASA’s Mariner Four got the first close-up images of Mars and in 1971 the Soviets sent a lander to the surface of Mars It crashed on landing but a second attempt survived long enough to send back twenty seconds of useful video From 1975 to 1980 two NASA orbiters and landers Viking 4
IntroductIon 5 One and Viking Two mapped the Red Planet and searched for signs of life In 1997 NASA placed the first-ever surface lander and the rover Sojourner on Mars In 2003 the European Space Agency joined the exploration of Mars sending landers and orbiters In 2011 NASA sent Curiosity the larg est and most sophisticated exploration rover ever to visit another planet Curiosity explored for two years and found evidence that liquid water had once existed on Mars of the twentieth century On July 20 1969 humans first set foot on the moon The Apollo 11 mission to the moon was one of the greatest scientific achievements But as exciting as these missions have been no humans have visited visited Mars That may change soon In 2017 NASA outlined its plans to send a manned mission to the Red Planet by 2033 But plans for Mars are a great deal bigger than those for the moon Scientists hope to one day colonize Mars If people are going to live work and study on Mars they are going to need something Mars doesn’t have much of oxygen The Martian atmosphere is 96 percent carbon dioxide and less than 2 percent oxygen Getting humans to Mars is a big challenge
6 oXYGEn Making sure they survive when they get there is an even bigger one and so is being able to return home Both surviving on Mars and getting getting back to Earth require oxygen NASA has a plan for that The Mars Oxygen In-Situ Resource Utilization Experiment called Moxie for short is NASA’s plan for producing oxygen from the atmosphere on Mars A machine would use an electric current to separate the carbon and oxygen atoms that make up the carbon dioxide in the Martian atmosphere The oxygen would then be available for astronauts to breathe and for firing the rockets that would send them back home The word moxie means bold and this is definitely a bold plan It’s also a necessary one if humans are going to do more than make a quick visit to Mars Humans cannot survive for more than a few minutes without oxygen But as important as it is to us now Earth hasn’t always had oxygen oxygen And even after humans came along it took a long time for us to understand what oxygen was Once we did we found a lot of ways to put it to use including firing rockets to get to other planets
1 Finding the Pieces Take Take a deep breath Now take another Breathe slowly Can you taste the oxygen in the air Probably not because oxygen is tasteless odorless and colorless You may not be able to see taste or touch oxygen but it is absolutely essential to life in our world Without it our planet might look more like Mars or the moon dry and lifeless There would be no clouds rain or snow because they each require water and water is nearly 90 percent oxygen Hydrogen accounts for the remaining 10 percent Without oxygen there would be none of the plants and animals that you see every day because oxygen is vital to nearly every organism on Earth Oxygen is an element Elements are made of only one kind of substance substance that cannot be broken down further The elements are the 7
