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.
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. |
and
Accessibility Certification