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NOVEMBER LAUNCHING SCHEDULED.

There's a parkina snot rem served for Canada 22,390 miles in space, and in Nover= ber 550 Ibs. of electronic equipment, solar cells, an- tenna and rocket fuel is sch- eduled to take occupancy.

Canada's first communica- tions satellite, named Anik and owned by Telesat Canada, is to be launched from Cape Kennedy by the U.S. tational Aeronautics and Space Admin- istration.

Assembly of the satellite is expected to heain shortly at the Huoahes Aircraft Co. in California. A network of 34 qround stations is beina con- Structed and ''mission con- trol!’ in Ottawa is nearina completion.

1f the launch qoes accord- ing to plan, the satellite will become the world's first domestic communications system in synchronous orbit, a circular orbit 22,300 miles directly over the equator.

In such an orbit, the sat- elite will take 24 hours to revolve around the earth, Since the earth rotates on its axis in the same period Antik will appear to remain Stationary over a single point on earth - 114 dearees west longitude, facing cent- ral Canada.

The satellite will become in effect, a relay tower several thousand miles hiaqh, which allows it to blanket vast areas of land. And be- cause it is qeostationary, expensive fully steerable antennas are not needed for around stations. |

From its central location Anik will cover all of Can- ada with television and mes- sade transmissions, Special

ASSEMBLY OF CANADA'S COMMUNICATION SATELLITE TO BEGIN SHORTLY

beamina techniques will aive all points nearly uniform sional strenath, while red- ucing: the sianal beamed out- side Canada,

The satellite has nels -

12 chan- 10 for commercial use

and two for stand-by~each cap-

able of transmittina one color TY sianal or up to 960 one-way telephone messaqes,. The siqnals will be nicked up

by 34 special ground stations,

which can redistribute them by conventional terrestial means.

Everything, of course, de- pends on a successful launch and precise quidance of the satellite into its slot - a task not lacking in challenae even after 1/4 years of world wide experience with satel” lites.

92% SUCCESS RATE

Anik's booster will be one of NASA's thrust-auqmented Thor-Delta rockets, which has a success rate of 92%. .The $7 million launch will put Anik into an alliptical orbit, 22,300 miles from earth at

its furthest point, or apoaee,

and.inclined to the equator about 28 deqrees. NASA's res- ponsiblityv ends when the ell- iptical orbit is achieved; all subsequent operations will be handled by Telesat from its control centre in Ottawa.

The first tmportant step is the transfer orbit needed to circularize the elliptical orbit at 22,300 miles and move the satellite down to the equator. To do this, a small rocket on the satellite will be fired at anoaee, be- tween the third and fifth

time Anik comes around,

Should the aponee motor fail to put Anik into the de- sired synchronous orbit, sm all on-board thrusters miaht be used, but onlv at the ex- pense of the lifetime of the satellite. (The thruster fue! is needed to maintain the satellite's position in space throughout, its ojected seven year life)

The transfer orbit is cru- cial, for if the satellite is not precisely located, it loses its value as a commun- ications system. So Telesat is takina special precautions,

Barry Murphy, executive - assistant to Telesat presid- ent David Golden, said !!uahes Aircraft has been asked to build a special trackina Station at Guam in the Pac- ific. This will provide pos- itional data on the satellite while it is still in the Eastern Hemisnhere so it can be more readily acquired as it comes into the “estern Hemisphere and Telesat pre-~ pares to fire the apocee motor. °

Mr. Murphy said: ‘Je want to fire the anoaee motor early in the flight. There are some limits on the numbe-

of clliptical orbits that

can transpire before you cir- cularize the orbit.'' For example, the inclination to the equator aets worse with each orbit, makina it rore difficult to amet Anik into the equatorial orbit,

Telesat has chosen not to have an in-house comouter capability to handle this complex manoeuvre, so Com- putel Systems Ltd. of Ottawa will provide its cornuter durina rehearsals and launch operations.

A second computer will ao. through the whole thina si- miltaneously, so it can cut in immediately if anythina qoes wrong with the firse