AGENA: early uncrewed spacecraft
APOLLO: three-person spacecraft designed to fly to the moon
ATTITUDE: the way the ship is pointed
BOOSTER: another word for a rocket
BURN: When a rocket’s engines light, it is called a burn, because it is burning fuel.
CAPCOM: The person in Mission Control who radios up all information to the crew. The capcom is always an astronaut who is not flying on the current mission; the name is short for capsule communicator.
CAPE KENNEDY: The launch site for spacecraft. Originally called Cape Canaveral.
CIRCUMLUNAR: A flight that whips around the back of the moon and comes home without orbiting. It is the moon’s gravity that tosses the spacecraft back to Earth.
COMMAND-SERVICE MODULE (CSM): The cone-shaped portion of the spacecraft that houses the crew is the command module; the astronauts and all the controls on their instrument panel command where the spaceship goes and what it does. The service portion is a cylindrical, twenty-four-foot structure attached to the rear of the command module like the trailer behind the cab of a truck. It contains the spacecraft’s main engine, the SPS, as well as much of its essential hardware, like oxygen tanks, water supply and batteries and fuel cells.
ENGINE BELL: The bell-shaped structure that protrudes from the back of the service module and helps direct the engine’s fire. There are engine bells at the bottom of rockets, too.
FLIGHT DIRECTOR: the boss of Mission Control, responsible for all final decisions throughout a flight
FLIGHT DYNAMICS (FIDO): the Mission Control console operator who managed the trajectory, or route, of the rocket and the Apollo spacecraft
FLIGHT PLAN: a detailed plan of every moment of the mission and the roles of every player on the ground and in the air
GANTRY: a tall, moveable, towerlike structure with a platform that supports the rocket and Apollo when they’re on the launchpad
GEMINI: two-person spacecraft designed for Earth orbit
JETTISON: let go or get rid of
LOSS OF SIGNAL (LOS): When an object blocks radio waves between a spacecraft and Earth, communication is lost.
LUNAR EXCURSION MODULE (LEM): A two-part ship. Its first task would be to land on the moon with its four legs and a powerful descent engine. When it was time to take off, the bottom half of the ship would serve as a launch platform, with explosive bolts and a guillotine system cutting the cables and other links to the top half, allowing an ascent engine to carry the remains of the spacecraft—which was essentially the crew cabin—up to lunar orbit.
LUNAR ORBIT INSERTION (LOI): the burn the Apollo’s main engine—known as the SPS—makes to settle the Apollo into orbit around the moon
MANNED: A mission that has humans aboard operating the craft. Today we say “crewed” since both men and women fly in space.
MERCURY: America’s first crewed spacecraft, designed for one person
MISSION CONTROL: The large auditorium-like room at the NASA space center in Houston where the spaceflight is managed. It houses consoles with experts who track and manage every technical aspect of the flight.
MASCON: Short for “mass concentrations”—the remains of heavy-metal meteorites that long ago crashed into the moon and buried themselves there. They make lunar gravity uneven.
PASSIVE THERMAL CONTROL (PTC): A slow, one revolution-per-minute rotisserie roll that would be initiated with a single burn of the Apollo thrusters and would continue indefinitely until there was a counterthrust—or a burn in the other direction—when the craft is in zero-g. It kept the spacecraft evenly warmed by the sun on all sides
PITCH: When the nose of spacecraft moves up or down; a 360-degree pitch would thus be a somersault.
RETROFIRE: When a spacecraft turns backward and fires its engine in front of it as it flies. It is used to slow the spacecraft down.
ROCKET: a projectile that can shoot a spacecraft into space by igniting its combustible fuel
ROLL: Roll is when the spacecraft moves the way a can or other cylinder would if you lay it on its side and give it a push so it rolls along the floor.
SATURN V: massive, thirty-six-story, three-stage rocket that would blast the Apollo spacecraft moonward
SERVICE PROPULSION SYSTEM (SPS): Engine on Apollo spacecraft. Needed to work properly at least twice on an Apollo mission; once to get into lunar orbit, once to get out.
SIMSUP: Simulation supervisors. Their job is to introduce uncertainty and problems into simulations of flights so that the technicians and the astronauts will be ready for any problems that might arise.
STATION-KEEP: When two vehicles stay at a fixed distance from each other, moving neither closer nor farther apart.
SUSTAINER ENGINE CUTOFF (SECO): shutdown of the Saturn V’s third-stage engine, after it was lit to push the astronauts out of Earth orbit and send them to the moon
TELEMETRY: the computer data that always streams down from the spacecraft to Earth, telling the controllers how the mission is functioning
THRUSTERS: Little engines positioned on the outside of a spacecraft. They help it maneuver in different directions.
TITAN BOOSTER: rocket that launched Gemini spacecraft
TRANS-EARTH INJECTION (TEI): the burn of the rocket’s engine that pushes a spacecraft out of lunar orbit and sends it back toward Earth
TRANSLUNAR INJECTION (TLI): the burn of a rocket that sends astronauts out of Earth orbit and out to the moon
VELOCITY: speed
YAW: Yaw is when the nose of a spacecraft waggles left or right; a 360-degree yaw would thus be a flat spin, moving around the way clock hands circle a clock face.
ZERO-G: In space, astronauts feel no gravitational pull, which allows them to float. One g is the gravitational environment of the Earth.