Riding Rockets

ET—External Tank. The orange fuel tank attached to the belly of a launching space shuttle. It carries 1.3 million pounds of liquid oxygen and 227,000 pounds of liquid hydrogen for the three liquid-fueled engines at the back of the orbiter.

EVA—Extra-Vehicular Activity. A spacewalk.

FCOD—Flight Crew Operations Directorate. The organization at Johnson Space Center having overall responsibility for crews involved in flight operations, including T-38, Vomit Comet, and shuttle flight operations. The astronaut office falls under the domain of FCOD.

FDO—Flight Dynamics Officer. The Mission Control position that oversees all aspects of the shuttle’s trajectory and vehicle maneuvers from liftoff to landing.

GIB—Guy-in-Back. Military slang for the backseat occupant of a two-place fighter aircraft.

GLS—Ground Launch Sequencer. A computer in the Launch Control Center at Kennedy Space Center that controls a shuttle countdown until thirty-one seconds prior to liftoff, at which time the shuttle’s own computers assume control of the countdown.

GPC—General Purpose Computer. One of five IBM computers that form the shuttle’s electronic “heart.” One of these is the BFS computer.See BFS.

GS—Government Servant. The title of civilians working for the government. A number system, e.g., GS-9, indicates the rank of the worker.

GWSA—George Washington Sherman Abbey.

HQ—Headquarters.

HST—Hubble Space Telescope.

ICOM—Intercom. The system used by astronauts to talk to one another when they are in the LES or separated between the upper and lower cockpits or between the shuttle cockpits and a Spacelab module.

IFR—Instrument Flight Rules. A term used in aviation to indicate a pilot is following the directions of an air traffic controller on the ground.

INCO—Instrumentation and Communication Officer. The MCC controller responsible for the command and data links between the MCC and the space shuttle.

ISS—International Space Station.

IUS—Inertial Upper Stage. A large Boeing-built booster rocket used to lift satellites into their final orbits and to accelerate space probes out of Earth orbit.

IVA—Intra-Vehicular Activity. Usually used as a crewmember title, i.e., IVA crewmember. A crewmember who helps spacewalkers prepare for a spacewalk and monitors them while they are outside the spacecraft.

JSC—Johnson Space Center in Houston, Texas.

KSC—Kennedy Space Center in Florida

LCC—Launch Control Center. The Kennedy Space Center team that directs the countdown and launch of a space shuttle.

LCG—Liquid Cooling Garment. A netlike long underwear worn under a spacesuit and that holds a maze of small tubes that circulate chilled water to prevent spacewalkers from overheating.

LDEF—Long Duration Exposure Facility. A bus-size satellite launched on shuttle mission STS-41C in 1984 and retrieved and returned to Earth by STS-32 in January 1990. LDEF carried several hundred passive experiments to understand the effects of space exposure on various materials.

LES—Launch/Entry Suit. The orange-colored spacesuits that astronauts wear for launch and reentry. These suits would automatically pressurize if there was a cabin pressure leak.

LOS—Loss of Signal. A call to the crew that the shuttle will soon be out of contact with Mission Control. Usually the call is given in a countdown format, as in, “Atlantis, you’ll be LOS in two minutes.”

LOX—Liquid Oxygen.

Mach—The engineering term for the speed of sound. Astronauts wear a Mach-25 patch indicating they have traveled twenty-five times the speed of sound.

max-q—An engineering term for the point in flight when an aircraft or spacecraft experiences the maximum aerodynamic pressure. Max-q (where the M is capitalized) is also the name of the astronaut band. Though there have been several generations of astronaut band members, the band name remains the same.

MCC—Mission Control Center. The Johnson Space Center team that directs a shuttle mission from “tower clear” (the moment the shuttle rises above the launchpad) until the “wheel stop” call at landing, at which time control is returned to Kennedy Space Center.

MDF—Manipulator Development Facility. A full-scale simulation of the Canadian robot arm and shuttle cargo bay in a building at Johnson Space Center.

MEC—Master Events Controller. A black box on the space shuttle that controls critical events like the commands to jettison the booster rockets and the empty gas tank.

MECO—Main Engine Cutoff. The moment in a shuttle launch when the three liquid-fueled engines shut down.

MLP—Mobile Launch Platform. The “launchpad” on which the space shuttle is stacked and that is carried to either Pad 39A or B by a massive tracked crawler.

MMU—Manned Maneuvering Unit. A space jet pack. An MMU has high-pressure gas thruster jets that allow an untethered astronaut to fly short distances from the space shuttle.