beacon explorer-c press kit

8/8/2019 Beacon Explorer-C Press Kit

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6 - /CINATIONAL AERONAUTI(S AND SPACE ADMINISTRATION WO 2-4odeWASHINGTON, DC. 20546 TELS WO 3-9USWFOR RELEASEt FRIDAY PM'St March 26, 1965RELEASE NO: 65-97

R PROJECT: BEACON EXPLORER-C (BE-C)CONTENTS

GENERAL RELEASE ........................... 1-6


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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TELS WO 2-4155E W S WASHINGTON, D.C. 20546 T WO 36925FOR RELEASEt FRIDAY PM ' sMarch 26, 1965RELEASE NO: 65-97

DEACON EXPLORER-CUSES 'TRAIN WHISTLE EFFECTt

IN EARTH MEASUREMENT

The National Aercnautics and Space Administration willlaunch no earlier than March 30 its newest satelliteusingthe "train whistle effect" of an orbiting radio signal.tomap irregularities in the Earth's gravitational field.


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The size of the Doppler shift, or shift in pitch,depends on how fast the train is going, how far the listeneris from the track and where the train is along the track.--hus, if the listener could measure the Doppler shift atseveral different times he could quickly compute 'where thetrain is with respect to where he is and how fast it is going.

If thed,trth were -a perfect sphere, a satellite would-trav~ellonga mooth.curve cal'led an ellipse. However,


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The ionosphere acts w a gigantic electrified mirror inspace for relaying long-range radio communications. Freeelectrons play a vital role in this phenomena.

The new Explorer also will be equipped to evaluate furtherthe use of laser (light amplification by stimulated emissionof radiation) techniques in deriving orbital and geodeticinformation and for deep space communication.

A radio attenuation experiment will be contained on


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The spacecraft is expected to have an operating lifetimeof about one year.

Explorer XXII and BE-C are physically identical exceptthat the new satellite will fly a laser signal detector, aphoto-sensitive device, designed to confirm strikes made bythe ground-aimed light beam during experiments when thespacecraft passes within range.


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The geodetic satellite program is directed by NASA withthe Department of Defense and the Department of Commerce asprincipal participants.

The BE-C project is part of the scientific and spaceexploration efforts of NASA's Office of Space Science andApplications. Project management of the satellite is assignedto the Goddard Space Flight Center, G.. enbelt, Md.

Working with Goddard are the University of Illinois,


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The radio attenuation measurement experiment also isdirected by OART with project supervision assigned to theLangley Research Center.

The satellite-borne silica reflectors were produced byBoxton-Beel Co., Brooklyn, N.Y. The reflector array wasassembled by General Electric Company's Space Technology Center,Valley Forges Pa.

(END OF NEWS RELEASE; TECHNICAL BACKGROUND FOLLOWS)


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Results from these investigations, coupled with thosefrom future geodetic satellites in the NASA series, will aidin more precise mapping of the Earth's surface and helpbroaden our understanding of the Earth's gravitational field.

Benefits expected from geodetic satellite studies includethe potential to improve world-wide navigation for ships atsea and the possibility of obtaining greater accuracy incalculating satellite and rocket trajectories.

Data obtained also should aid in understanding the basic


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from Explorer XXII. It involves the global effort to map theionosphere using the network of 86 ground stations locatedin 36 different countries operated by 62 scientific organizationson a voluntary basis. (See map of station locations).

Radio signals sent by the satellite are received by theground stations when the satellite is within range. Study ofchanges in the radio signals as they pass through the ionospheregives network scientists data on the electron content ofthe ionosphere at a given time and place. As with Explorer


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Similar information is being sent by Explorer XXII,orbiting at an angle of inclination of 80 degrees. Theinclination for BE-C will be 41 degrees.

The beacons carried by BE-C are described as four co-herent unmodulated continuous wave transmitters. The fre-quencies used are 20.005, 40.010, 41.01 and 360.00 mega-cycles. The signals are picked up by ground stations in theglobal network.

A typical ground station, costing less than $5,000,


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Laser Experiment

Continuing the laser (light beam) experiments inaugura-ted by Explorer XXII, NASA scientists will extend the studyof techniques required for deriving geodetic and orbitalinformation.

The rate of return of the light beam to a ground devicecapable of recording the return pulse is the basis of a satel-lite optical tracking system being developed by the Goddard


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This problem accounts for the only change in the laserexperiment from Explcrer XXII the addition of a light-sensitivedetector on board the spacecraft.

When the laser beam strikes the satellite, the detectorwill convert the light to electrical energy and amplify it.The spacecraft commutator will send a signal to the groundto confirm the strike.

An array of 360 fused silica reflectors is mounted on


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In the upper atmosphere and in space, combustion gasesrushing from a rocket engine nozzle do not form a compact jet

but instead fan out into a spreading shape engineers call arocket plume. The plume becomes wider as atmospheric pressuredecreases.

Ionized gases in the rocket plume can block radio trans-missions in much the same way that radio blackouts occur onreentering spacecraft because of the hot, ionized gas cap.The plume can also: disturb the ordinarily smooth airflow aiog-


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Materials selected for the experiment are freon, water,argon and nitrogen. Their basic properties differ, and theeffect of each on signal recovery will be studied. The argonand nitrogen serve also as pressure sources to expel thefreon and water from their containers. A timer and valvesystem control release of the materials in proper sequence.

-more-


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The Langley Research Center experiment is a part ofProject RAM -- the initials stand for Radio AttenuationMeasurements -- headed by Theo E. Sims.

Beacon Explorer-C Fact SheetLaunch On or about March 30, 1965NASA Wallops Station, Wallops Island, Va.Four-.stage Scout launch vehicleApogee 670 statute miles (1,080 kilometers)Perigee 620 statute miles (1,000 kilometers)Inclination 41 degreesPeriod One hour, 45 minutesLifetime One year


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Communications and data-handling systemTelemetry: Three basic units: (1) 35-channelamplitude modulation (PAM) commutator,(2) eight channel pulse durationmodulation (PDM) commutator and (3)seven telltale register functions withpulse code modulation (PCM) format.Transmitter: 400 milliwatts at 136.74 mc on acontinuous basis

Tracking: Stations of the world-wide Space Trackingand Data Acquisition Network (STADAN)operated by the Goddard Space FlightCenter.Scout Launch Vehicle

Scout is a four-stage solid propellant rocket capable of


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Scout is capable of placing a 2 4 0-pound payload into a300-mile orbit or of carrying a 100-pound scientific package7,000 miles out from Earth.

Scout stages include the following motors:First stage: Algol IIB- 105,000 pounds thrust, burning 68 seconds.Second stage: Castor I- 62,000 pounds thrust, burning 42 seconds.Third stage: Antares (ABL X-259)- 24000 pounds thrust, burning 36 seconds.Fourth stage: Altair (ABL X-258)


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Goddard Space Flight CenterDr. Harry J. Goett, DirectorDr. John W. Townsend, Jr., Associate Director, Officeof Space Science and Satellite ApplicationsFrank T. Martin, Project ManagerRobert E. Bourdeau, Project ScientistJohn T. Shea, Project CoordinatorLarry H. Brace, Electron Density ExperimentDr. Henry H. Plotkin, Laser Project Scientist

Langley Research Center(Radio Attenuation Measurement Experiment)


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Applied Physics Laboratory, Johns Hopkins University

R. R. Newton, Scientific Investigator, Supervisor SpaceResearch and Analysis Branch.

Donald R. Biauco, Project Engineer, Space Research andAnalysis BranchParticipating Organizations

University of IllinoisPennsylvania State UniversityStanford University


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BEACON EXPLORER CCUTAWAY VIEW

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BEACON EXPLORER SATELLITE MONITORING STATIONSw- -

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Stations underlined added since launch of Explorer XXII

beacon explorer-c press kit

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