New Terms For Space Trip

Press, Volume CVIII, Issue 31865, 18 December 1968, Page 26

New Terms For Space Trip

(N.Z.P.A. Reuter—Copyright) CAPE KENNEDY.

The Apollo 8 spacecraft’s historic flight around the moon at Christmas will bring new terms to the already familiar language of the space age.

Space watchers around the world, accustomed to such jargon as “blast-off,” “retrofire” and “splash-down,” will now have to understand “loi,” “tli” and “res,” and the meaning of such exotic words as “penumbra,” “perilune" and “selenocentric.”

In the vocabulary of the astronaut, common words like “burn” and “coast” assume different meanings, and rarer ones like “penumbra” and “cislunar" are commonplace. The following is a glossary of some of the terms that will be used during the Apollo 8 mission. Ablating materials—special heat dissipating materials on the surface of the spacecraft that can be sacrificed (carried away, vapourised) during re-entry. Abort—the cutting short of an aerospace mission before it has accomplished its objective.

Adapter skirt—a flange or extension of a stage or section that provides a ready means of fitting another stage or section to it. Ambient—environ mental conditions such as pressure or temperature.

Antipode—point on surface of planet exactly 180 degrees opposite from reciprocal point on a line projected through centre of body. In Apollo 8 use. antipode refers to a line from the centre of the moon through the centre of the earth and projected to the earth surface on the opposite side. The antipode crosses the mid-Pacific recovery line along the 165th meridian of longitude once each 24 hours.

Apocynthion point at which object in lunar orbit is farthest from lunar surface —object having been launched from body other than moon. (Cynthia, Roman goddess of moon.) Acquisition and tracking

radar—a radar set that searches for, finds and tracks a spacecraft. Apogee—the highest altitude of an orbiting spacecraft. Perigee is the lowest altitude. Apolune—point at which an object launched from the moon into lunar orbit is farthest from lunar surface. Burn—the firing of a rocket, measured in seconds. Burn-out—the point when combustion ceases in a rocket engine. Canard—a short, stubby wing-like element affixed to an aircraft or spacecraft to provide better stability. Cap coin—capsule communicator —person on a ground station assigned to communicate with astronauts in flight. Celestial guidance the guidance of a space vehicle by reference to celestial bodies. Chaff cluster of fine particles sometimes visible outside a spacecraft. Cislunar adjective referring to space between earth arid the moon, or between earth and moon’s orbit. Closed door automatic control units linked together with a process to form an endless chain. Circumlunar flight—a flight around the moon, without going into orbit. Command module (C.M.) — that part of the spaceship housing the crew. Coast—on the way to the moon, and on the way back, the Apollo coasts through the vacuum of space. C.S.M.—the Apollo includes the C.M. and the service module (S.M.) containing engine and instruments. Together they are referred to as C.S.M. Deboost—a retrograde manoeuvre which lowers either perigee or apogee of an orbiting spacecraft. Not to be confused with deorbit. Delt V—velocity change., Digital computer—a computer in which quantities are represented numerically and which can be used to solve complex problems. Down-link—the part of a communication system that receives, processes and displays data from a spacecraft. E.O.—earth orbit insertion. Entry corridor—the final flight path of the spacecraft

before and during earth re-entry. Escape velocity—the speed a body must attain to overcome a gravitational field, such as that of earth. The velocity of escape at the earth’s surface is 36,700 feet per second. Free return—Apollo spacecraft are launched from earth; on a path that takes them around the moon and back without the need for any additional rocket power. This is accomplished by a combination of speed and the pull of earth and moon gravity. Fuel cell an electrochemical generator in which the chemical energy from the reaction of oxygen and fuel is converted directly into electricity. The spacecraft’s electrical power system (E.P.S.) consists of three of these cells.

G.E.T. ground elapsed time. The number of days, hours, minutes and seconds [after lift-off. G.E.T. is used to record when events will

take place during a flight. Heliocentric sun-centred orbit or other activity which has the sun as its centre. Inertial guidance—a sophisticated automatic navigation system using gyroscopic devices. It absorbs and interprets such data as speed and position, and automatically adjusts the vehicle to a pre-

determined flight path. Essentially, it knows where it is going and where it is by knowing where it came from and how it got there. It does not give out any signal so it cannot be detected by radar or jammed. Injection—the process of injecting a spacecraft into a calculated orbit. L.O.l.—lunar orbit insertion. L.O.X.—liquid oxygen. L.M.—lunar module. Section of spaceship that will eventually take two men from their orbiting craft to the moon and back. Multiplexing simultaneous transmission of two or more signals on a single channel. Parking orbit temporary orbit before adjustments are made for permanent one. Penumbra—semi-dark portion of a shadow in which light is partly cut off. For

example, the surface of the i moon or earth away from the sun. Pericynthion— point nearest moon or object in lunar orbit—object having been launched from body other than moon. Perilune—the point at I which a satellite (e.g. a; ■ spacecraft) in its orbit is closest to the moon. Differs from pericynthion in that the orbit is moon-originated. R. —the spacecraft’s attitude in space is controlled by a number of small rocket engines called the reaction control system. S. spacecraft L.M. adapter. Housing for the L.M. in the early stages of the flight, once on the way to the moon, four thin metal S.L.A. panels peel away and the L.M. is hooked on to the C.S.M. for the rest of the way. S. service propulsion system. The Apollo’s own 20,5001 b thrust rocket engine used to propel the ship in space after the main rocket falls away. Selenographic—positions on the lunar surface used to describe its physical geography. Selenocentric—orbit having! the moon as its centre. T. —trans-earth injection. The moment when the astronauts fire the S.P.S. to return to earth. T.L.l.—translunar insertion —the time when the Apollo heads for the moon from earth orbit. Telemetry—system of taking measurements in a spacecraft in flight and transmitting them by radio to a ground station. Umbra—darkest part of a shadow in which light is i completely absent, for ex[ample, the surface of the [moon or earth away from the [sun.