3 Space Communications Look at Project OSCAR History Operating Modes Prediction SoftwareHow do I get startedWho Else Uses Amateur SatellitesFuture Satellites
4 Russian Sputnik Oct 1957- Sputnik Beacons on 20.003 Mhz and 40.010 Mhz Near WWV signalsBeeping signals only
5 Moon Bounce (EME) First Attempt by Amateurs in Space Communications W4AO, Ross Bateman; and W3GKP, William L. Smith transmitted signals at the moon and heard the return echoes of their own signal.Proved Space Communications (1953)
6 Balloon Flights1959- W6TNS Don Stoner proposed to build a spacecraft with a transponder on board in Feb 1961 QST ArticleUsed High Altitude Balloon With 6m input and 2m Output Repeater Payload Onboard
7 PROJECT OSCARIn 1960 a group of radio amateurs in Sunnyvale California read Stoner’s article and created a group called Project OSCAR.The OSCAR stood for Orbiting Satellite Carrying Amateur Radio.Convince the U.S. Government that amateur satellites provide useful functions in the areas of scientific exploration, disaster communications, and science education.
8 OSCAR 1 The First Satellite Built by the Project OSCAR Group. It Transmitted a 140mW Beacon Signal on 2 Meters at 145 MHz.The Sent the Signal “…. ..” “HI” in Morse Code .Signal Speed Corresponded Inside Temperature.The Project OSCAR Group Worked with the U.S. Air Force to add the Amateur Satellite as an Auxiliary Payload. (Ballast)The U.S. Air Force Launched OSCAR I as a First Ever Auxiliary Package that was Ejected From the Parent Spacecraft.Ejection Mechanism Subjected to Stress, Thermal, and Vibration Testing and Analysis and was Centered around a $1.15 Spring from Sears and Roebuck.The Air Force Recommended that They (the Commercial Community) Study the OSCAR 1 Satellite.
9 OSCAR 1 RESULTSReported Contacts in 28 countries, over 570 Amateurs Copied the SignalRemained in Orbit for 22 DaysData Gathered, was used to Study Ionosphere Propagation and Process Orbital DataThe Project Demonstrated the Abilities to Design, Build, Coordinate with Government AgenciesOSCAR I builders were often asked how much did it cost. Out of pocket expensed for all the materials to build the satellite at about $26.
11 OSCAR IISame Basic Design with the Exception of Different Thermal Coating.Reduced Internal TemperaturesExtending Battery LifeThe Output Power Reduced from mW to 100mW Reducing Power DrainThe Life of this Satellite - 18 days, 295 Orbits Before the Telemetry Beacon was Lost.
12 OSCAR III OSCAR III Carried Two Beacon Transmitters One to Provide TelemetryA Second with a Continuous Carrier for Propagation Studies and Tracking.Also Carried a 50 khz wide transponderReceived on 146 mhzAmplified and Retransmitted the signal at about 144 mhz.This Was the First Satellite Allowing Amateurs to Communicate Via a Space Vehicle.Launched in March 1965 in a Higher Orbit than Previous TwoTransponder Operated for 18 Days and Approximately 1000 Amateurs in 22 Countries were Heard.
13 Current Popular Satellites AO – 7AO – 27SO - 50AO - 51VU - 52ISS (ARISS Program)PCSAT (US Naval Academy)
14 Transponder Operating Modes And Prediction Software This installment we will look at the different modes of operation and some of the software packages to allow tracking or better stated, prediction of satellites at your station.
15 Transponder Operating Modes Analog Voice and CWSSB CW and Voice (Multiple Channel)FM Voice only (Single Channel)Digital ModesPacket (Store and Forward)1200 baud FSK9600 baud PSKAPRSTransponders (satellites) operate in various modes, voice and digital
16 Analog SSB Mode Single Side Band (FO-29 Inverting) 2m Uplink: – MHz SSB/CW70cm Downlink: MHz SSB/CWNOTE:Normal – UP/DOWN link Frequencies Track TogetherInverting – UP/DOWN link Frequencies Don’t Track TogetherSingle sideband is similar to what you use in HF communications
17 Analog Modes Satellites AO 7 (SSB) Mode B 70cm Up 2m Down FO 29 (SSB) Mode J 2m Up 70cm DownVU 52 (SSB) Mode V 2m Up Mode U 70cm DownSO 50 (FM) Modes VUAO 51 (FM) Modes VU, LU …AR(ISS) (FM) MHz up MHz DownAO 16 UP 2M (FM) Up 70CM (DSB) Down
19 Prediction Software Used to Predict Satellite Passes For Your Station’s Location-AOS Acquisition of Signal-LOS Loss of SignalAzimuth (From North)Elevation (Above Local Horizion)Doppler Shift (Frequency Tuning)
39 System Tasks When Satellite is in Range Antenna ControlCompute Satellite PositionSend Azimuth Elevation to controllerSteer the Antenna Array During the PassRadio ControlCompute FrequencyUplink Doppler ShiftDownlink Doppler ShiftSend Data To Radio
42 Stamp II Micro-Processor Reads Voltage to Determine PositionAZELCalculates New Position for ArrayTurn on/off Proper Relay to Move ArrayLoop and Do It Again Until Pass is CompleteSample of Program in Stamp II Processor
49 Future Satellites “EAGLE” (Built by AMSAT) P3E (Built by AMSAT DL) High Earth Orbiting (Elliptical Orbit)Software Defined Transponder (Software Defined Radio)Linear Transponders, DigitalP3E (Built by AMSAT DL)High Earth OrbitTest Bench for P5A Mars MissionLinear Transponders (Many Bands)Intelsat Geo-Stationary Available full timeFull Time AccessEmergency / Disaster CommunicationsSuitSat II
50 WEB Links www.satscape.co.uk www.heavens-above.com www.amsat.org
51 SUMMARY Look at Project OSCAR History Operating Modes Prediction SoftwareGetting StartedOther User of Amateur SatellitesFuture Projects