Orion: America's Next Generation Spacecraft (4.7 Mb PDF) - NASA

The test vehicle is
readied for launch at
White Sands Missile
Range’s Launch
Complex 32E.
The launch abort system, positioned on a tower atop
the crew module, activates within milliseconds to propel
the crew module to safety in the event of an emergency
during launch or climb to orbit. The system also protects
the crew module from dangerous atmospheric loads and
heating, then jettisons after Orion is through the initial
mission phase of ascent to orbit.
The crew module is the transportation capsule that
provides a safe habitat for the crew, provides storage for
consumables and research instruments, and serves
as the docking port for crew transfers. The crew
module is the only part of Orion that returns to Earth
after each mission.
The service module supports the crew module from
launch through separation prior to reentry. It provides
in-space propulsion capability for orbital transfer, attitude
control, and high altitude ascent aborts. When mated
with the crew module, it provides the water, oxygen and
nitrogen needed for a habitable environment, generates
and stores electrical power while on-orbit, and maintains
the temperature of the vehicle’s systems and components.
This module can also transport unpressurized cargo and
scientific payloads.
The spacecraft adapter connects the Orion Crew
Exploration Vehicle to the launch vehicle and protects
service module components.