COMSTAR 4-D Press Kit

8/7/2019 COMSTAR 4-D Press Kit

1/8

NS News8NJation~il Aeronatitics andSwxce Adnmirlstr1tionW(aslrngt0fo ) C 20546AC 202 755 t837(0

For ReleaseKen SenstadHeadquarters, Washington, D.C. IMMEDIATE(Phone: 202/755-8331)

RELEASE NO: 81-27

NASA TO LAUNCH COMSTAR D-4 COMMUNICATIONS SATELLITEThe fourth in the COMSTAR series of domestic communications

satellites owned by the COMSAT General Corp., Washington, D.C.,will be launched on board an Atlas Centaur rocket no earlier thanFeb. 19, 1981, by the NASA Kennedy Space Center from the CapeCanaveral Air Force Station, Fla.'The 6.1-meter (20-foot) high, cylindrical-shlaped satellite,

weighing 1,516 kilograrms (3,342 pounds) at launch, -arries 12transponders, or channels, each capable of reidying 1,500 one-wayvoice circuits, giving it an overall communications capabilityof 18,000 simultaneous high quality, two-way telephonetransmissions.

It will be positioned in a geosynchiLonous orbit over thePacific Ocean at 127 degrees west longitude providing communica-tions services to major metropolitan areas of the continentalUnited States and Hawaii.

February 10, 1981

-mo Ie


2/8

-2-

COMSTAR satellites are built by the Hughes Aircraft Co.,Culvet City, Calif. Their entire communications capability isleased by COMSAT General to American Telephone and Telegraphwhich operates ground stations serving New York, Chicago, SanFrancisco and Atlanta. Three other COMSTAR ground stations,operated by GTE Satellite Corp., a subsidiary of General Tele-phone and Electronics, serve Tampa, Los Angeles and Hawaii.

The Atlas Centaur launch vehicle will place the COMSTAR D-4into a highly elliptical "transfer orbit" ranging from a lowpoint of 547 kilometers (340 miles) to an apogee or high point of35,788 km (p2,240 mi.) above the Earth.

After the satellite separates from the Centaur stage, theCOMSAT Control Center in Washington, D.C., will take over opera-tional control and about 48 houts after launch, it will commandthe satellite's apogee kick motor to fiie in order to circularizethe orbit at geosynchronous altitude over the eCjuatoi. At thataltitude, because the speed of the satellite in o01bit matches therotational speed of the Earth, the satellite temains over onespot.

NASA'.:- Lewis Research Centei, Cleveland, has management re-sponsibill ty for Atlas Centaul devel opment and operation. TheKennedy Space Centet, Fla., is assigned launch responsibilityonce the Atlas Centaur reaches Cape Canavei al.

-mel e-


3/8

3-

Overall direction of the program is vested in che Office ofSpace Transportation Operations at NASA Headquarters, Washington,D.C. NASA is reimbursed by COMSAT General for the cost of theAtlas Centaur and related launch services.

(END OF GENERAL RELEASE; BACKGROUND INFORMATION FOLLOWS.)

-more-


4/8

4-

ATLAS CENTAUR LAUNCH VEHICLE STATISTICS

The COMSTAR satellite will be launched by the Atlas Centaur.The launch vehicle has the following general characteristics:

Hleight: 40.8 m (134 ft.) including nose fairingDiameter: 3.05 m (10 ft.)Total Liftoff Weight: 147,926 kg (326,120 lb.)(including spacecraft)Liftoff Thrust: 1,917,088 newtons (431,000 lb.)(sea level)

Atlas Stage

The Atlas stage consists of the booster section (one-halfstage) and the sustainer'vernier section (first stage). The Atlasis manufactuIed by General Dynamics/Convair, San Diego, Calif.,using thlj MA-' engine system supplied by Rocketdyne Div. of Rock-well Intetnational, Canoga Park, Calif. The MA-5 system consistsof two booster engines, one sustaine encjine and two v'rnierengines. The Atlas stage has the following characteri tics:

lieightt: 21.2 m (69.5 ft.)Diameter: 3.05 m (10 ft.)Piopellants: RP-l kerosene for fuel and liquid oxygen(LOX) as the oxydizerThlust: Total Booster: 1,645,760 N (370,000 lb.)(sea level)

Sustainer: 266,880 N (60,000 lb.)Total Veinier: 4,448 N (1,000 lb.)

Total Llftott Thiust: 1,917,088 N (431 ,OO0 lb.)

-. me) i e -


5/8

5-

Centaur Stage

The Centaur (second stage) is manufactured by GeneralDynamics/Convair, using the RL-10 engines by Pratt and WhitneyAircraft Group, West Palm Beach, Fla. This stage has the fol-lowing characteristics:

Height: 9.] m (30 ft.)Diameter: 3.05 m (10 ft.)Propellants: Liquid hydrogen for fuel and liquid oxygenfor the oxidizerThrust: 133,440 N (30,000 lb.) (vacuum)

LAUNCH OPERATIONS

NASA's John F. Kennedy Space Center is responsible for thepreparation and launch of Atlas Centaur AC-42, which will carryCOMSTAR D-4 into orbit.

The Atlas booster was erected on Pad A a. Launch Complex 36at Cape Canaveial Air Force Station on Nov. 10. The interstageadapter was mated with the booster on Nov. 11, and the Centaurupper stage was erected atop the stack the same day.

The COMSTAR satellite arrived on Nov. 18 and underwent ini-tial checkout in Hangar AM on Cape Canaveral Air Force Station.The spacecraft was moved to the Delta Spin Test Facility Dec. 2and retutned to Hangar AM on Dec. 9. On Feb. 3 it was moved tothe Spaceciaft Assembly and Encapsulation Facility-2 in theKennedy Space Center's Industrial Area. There it was mated tothe apogee kick motoi; its positioning and orientation system wasfueled and pressurized. It was mated to the flight adapter, andthe sepaiation clamp and solar panels weic installed. Ol Feb. 10thC satellite was encapsulated in the payload shroud which willpiotect it duiing fl ight through the atmosphere.

COMS'T1," was moved to tlhe pad and mated to the boosterFeb. I I

-mer, C-


6/8

OD

0'

LA)

L4

aUCa

CD

CN

CD

1

C

@O

LA

n

C44

O

o

N

a

a

2.

U

r

C

I

sr

o

O

-

S

-

-

0

0

>

0

>

)

0

0

N

.

(

-

=

a

O

C

O

C

U

O

e

U

l

-e@-

,(

.7O

E

4

a

A

(

V.

.4.4H

LA

LAi

S

-4

O

)

o

U

0

1

v

0

C

0

Q

*

-

(04@

.

C

(

C

V

C

C

C

)

44

-:

a

00

:2

O:1

v


7/8

7-

THE COMSTAR TEAM

NASA Headquarters

Dr. Stanley I. Weiss Associate Administrator forSpace Transportation OperationsJoseph B. Mahon Director, Expendable LaunchVehicles ProgramF. R. Schmidt Manager, Atlas Centaur

Lewis Research Center

Dr. J. F. McCarthy DirectorLawrence J. Ross Director of SpaceRichard E. OrezechowsKi COMSTAR Mission Project Engineer

Kennedy Space CenterRichard G. Smith DirectorThomas S. Walton Director, Cargo Operations

Charles D. Gay Director, Deployable PayloadsOperationsJohn Gossett Chief, Centaut Operations

D. C. Sheppard Chief, Automated Payloads Division

Art Sawyer Spacecraft Cooldinatoi

-ntal I-


8/8

-8-

COMSAT General/COMSTARDr. Joseph V. Charyk President, COMSATR. Bodman President, COMSAT General Corp.John L. Martin, Jr. COMSAT General Vice President

Systems Engineering and OperationsC. Guthrie Manager, COMSTAR ProgramL. HI. Westerlund Manager, Engineering Space Segment

Development and Control

Hughes Aircraft Co.11. Leap COMSTAR D-4 Project Manager

CONTRACTORS

Geneial Dynamics/Convair Atlas Centaur launch vehicleSan Diego, Calif.Ileneywell Aerospace Division Centaui guidance inertialSt. Petershutg, Fla. measurement groupPlatt and Whitney Centaut RL-lO enginesAirciaft Grroup1\est Palm Beach, Nla.Telcdync Industries, Inc. Digital computel ni t/PCMNo IthIi dge, Calif. telecIetLRocketdyn1%c Division 'A- ,- pli UPlIcSio l s'stemsRockweil Inteinati onal Cuoip.Canoga Palk, Calif.

I rJx: , .)1, 0

Documents

COMSTAR 4-D Press Kit