By Associated Press

Orbiter: Part of the shuttle that carries astronauts and cargo; its sleek, winged profile is visible during landings.

External tank: Huge fuel tank that supplies oxygen and hydrogen to main engines during launch.

Solid rocket boosters: Two rockets flanking the orbiter that burn solid fuel during first minutes of ascent and then drop off, parachuting into the ocean.

Main propulsion engines: There are three, all located at bottom of orbiter.

Flight deck: Located just behind orbiter's nose.

Cargo bay: Located at center of orbiter's fuselage.

Payload doors: Two curved doors atop the fuselage.

Heat-resistant tiles: Tiles that line the orbiter's belly to protect it during the intense heat of returning to the atmosphere.

Insulating foam: Heat-resistant foam that covers outside of external fuel tank.

Body flap: Control panel hinged to back of fuselage to help control during descent.

Delta wings: Two triangular wings allow orbiter to glide to earth without the help of engines.

Elevons: Panels that help give control to wings.

Vertical stabilizer: Orbiter's tail fin.

Main landing gear: One set below each wing, each with two tires.

Nose landing gear: Third set of landing gear beneath the orbiter's nose.

Forward control thrusters: Small rocket engines studded around orbitor's nose that help maneuver in space

Heat sensors: Devices arrayed all around the craft to measure temperature.

Orbital maneuvering system: Two engines mounted in pods outside the back of the fuselage, for power when entering or leaving orbit.

Reaction control system: Set of engines on each side of back fuselage, used to control motion while maneuvering out of orbit and returning into the atmosphere.

Split rudder-speed brake: Panel on the vertical stabilizer that splays apart to increase drag and slow the craft during landing. Moved together, this part acts like a rudder to control motion.