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Why do astronauts eat tortillas instead of bread?
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What will replace the Space Shuttle?
Why do robots travel places before people?
Why return to the Moon before going to Mars?
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What would you find on the Moon’s surface?
What would you hear in a weather report from Mars?
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Subject Matter Expert: Roger Crouch and Marc Timm

The history of NASA’s space program is filled with dreams that, through much hard work, have become realities. Each challenge required new designs in spacecraft. Each success was the final product of many trials and errors.

NASA has allowed us to turn what was once science fiction into science fact.

In 1865, Jules Verne seemed to be looking into the future as he wrote his science fiction book From the Earth to the Moon. In this book, three men are launched to the moon from Florida. Just like the Apollo astronauts in the 1960s, they experienced reduced gravity which made them feel weightless in space. The book’s characters also used retrorockets and returned to Earth by landing in the ocean. What was once only imagination, NASA turned into achievements.

But it took many steps to get where we are today in space exploration.

NASA's human spaceflight program used three similar – yet slightly different - spacecraft to help astronauts prepare and ultimately land on the moon. The Mercury program (1961-63) used a space capsule that could hold one astronaut. Its cone-shaped design was kept and used with the larger two-man capsule for NASA's Gemini program (1965-66). The same design was still evident in the even larger three-man capsule for the Apollo Program (1968-72).

From 1963 to 1975, NASA tested a group of lifting bodies. The characteristics of these winged research vehicles led to the development of the space shuttle.

Components of the Space Shuttle system.

Image to right: The components of the Space Shuttle system: Orbiter, External Tank, and Solid Rocket Boosters. Photo Credit: NASA

Today's space shuttle is a unique spacecraft system. It can operate on land, in the atmosphere, and in space. The space shuttle combines the features of a rocket, aircraft, and glider. It carries satellites and other cargo into Earth orbit. The space shuttle is the first space program to reuse most of its components. The orbiter and solid rocket boosters are reused – only the external tank is not recovered.

From its first flight on April 12, 1981 to today, no other spacecraft has been used for so many years. NASA has scheduled space shuttle flights until completion of the International Space Station. Once that goal is met, the shuttle fleet will be retired.

What type of spacecraft WILL replace the space shuttle? NASA is designing and testing models of a possible future spacecraft that will not only replace the space shuttle but also take us back to the moon and to Mars. This spacecraft is called the Crew Exploration Vehicle (CEV). To meet the goals of NASA's Vision for Exploration, the CEV will have different models that are like different models of the same automobile. An expendable rocket will launch the CEV, though many components of the CEV will be reusable.

The crew module will be a capsule similar to the one used in the Apollo program. This module will be able to dock with the International Space Station. Other types of CEVs will serve as operation bases on the moon's surface. Still other models might travel to asteroids, Mars, or possibly destinations even farther away.

The CEV designed for Phase ONE will carry astronauts into Low Earth Orbit (LEO). LEO is an orbit in which a spacecraft or satellite orbits close to Earth. This range is between 320 – 800 kilometers (200-500 miles) above the Earth’s surface. Orbiting this close to the Earth requires that the spacecraft travel very fast to resist the pull of Earth's gravity. The CEV will transport a crew of up to six between the Earth's surface and LEO to help scientists prepare to return astronauts to the moon.

Phase TWO will develop CEVs to place people on the moon for at least four days. This phase would have two CEVs leave Earth’s orbit with crews of 2-3 and large amounts of cargo. Much of the cargo will be left on the moon. Lunar samples will be collected and returned to Earth with the astronauts.

Phase THREE would take people to live on the moon for several months to prepare for a future crewed mission to Mars.

Phase FOUR will be a Mars flyby mission. All equipment needed to perform a crewed mission to Mars - without actually landing a person on the Martian surface - will be tested during this phase, which is similar to what happened in preparation for the Apollo 10 mission. The Lunar Module spacecraft, prior to landing a man on the moon, was tested in lunar orbit without actually landing on the lunar surface.

Phase FIVE takes us to Mars, landing a person on Mars sometime after 2030.

Keep your eyes and ears open to stay on top of new spacecraft designs that will help NASA complete the International Space Station, return to the moon, and then travel to Mars. NASA continues to dream dreams and newly designed spacecraft will make those dreams come true.

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National Science Education Standards (NSES)

The following National Education Standards are addressed in this educational package.

Science (NSTA/NRC)
Technology (ITEA)

For an alignment see the Educator Section.