Amateur Space Communications Albert - N4ZFG

Space Communications Look at Project OSCAR History Operating Modes Prediction Software How do I get started Who Else Uses Amateur Satellites Future Satellites

Russian Sputnik Oct 1957- Sputnik Beacons on 20.003 Mhz and 40.010 Mhz Near WWV signals Beeping signals only

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)

Balloon Flights 1959- W6TNS Don Stoner proposed to build a spacecraft with a transponder on board in Feb 1961 QST Article Used High Altitude Balloon With 6m input and 2m Output Repeater Payload Onboard

PROJECT OSCAR In 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.

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.

OSCAR 1 RESULTS Reported Contacts in 28 countries, over 570 Amateurs Copied the Signal Remained in Orbit for 22 Days Data Gathered, was used to Study Ionosphere Propagation and Process Orbital Data The Project Demonstrated the Abilities to Design, Build, Coordinate with Government Agencies OSCAR 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.

OSCAR 1 MODEL

OSCAR II Same Basic Design with the Exception of Different Thermal Coating. Reduced Internal Temperatures Extending Battery Life The Output Power Reduced from 140mW to 100mW Reducing Power Drain The Life of this Satellite - 18 days, 295 Orbits Before the Telemetry Beacon was Lost.

OSCAR III OSCAR III Carried Two Beacon Transmitters One to Provide Telemetry A Second with a Continuous Carrier for Propagation Studies and Tracking. Also Carried a 50 khz wide transponder Received on 146 mhz Amplified 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 Two Transponder Operated for 18 Days and Approximately 1000 Amateurs in 22 Countries were Heard.

Current Popular Satellites AO – 7 AO – 27 SO - 50 AO - 51 VU - 52 ISS (ARISS Program) PCSAT (US Naval Academy)

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.

Transponder Operating Modes Analog Voice and CW SSB CW and Voice (Multiple Channel) FM Voice only (Single Channel) Digital Modes Packet (Store and Forward) 1200 baud FSK 9600 baud PSK APRS Transponders (satellites) operate in various modes, voice and digital

Analog SSB Mode Single Side Band (FO-29 Inverting) 2m Uplink: 145.900 – 146.000 MHz SSB/CW 70cm Downlink: 435.900 - 435.800 MHz SSB/CW NOTE: Normal – UP/DOWN link Frequencies Track Together Inverting – UP/DOWN link Frequencies Don’t Track Together Single sideband is similar to what you use in HF communications

Analog Modes Satellites AO 7 (SSB) Mode B 70cm Up 2m Down FO 29 (SSB) Mode J 2m Up 70cm Down VU 52 (SSB) Mode V 2m Up Mode U 70cm Down SO 50 (FM) Modes VU AO 51 (FM) Modes VU, LU … AR(ISS) (FM) 144.49 MHz up 145.800 MHz Down AO 16 UP 2M (FM) Up 70CM (DSB) Down

New Mode Designations Example: Mode V/U VHF Uplink UHF Downlink Band V 145 MHz U 435 MHz L 1.2 GHz S 2.4 GHZ Example: Mode V/U VHF Uplink UHF Downlink Mode L/U 1.2 GHZ Uplink UHF Downlink

Prediction Software Used to Predict Satellite Passes For Your Station’s Location -AOS Acquisition of Signal -LOS Loss of Signal Azimuth (From North) Elevation (Above Local Horizion) Doppler Shift (Frequency Tuning)

Doppler Shift

Manual Tracking (Pre PC’s)

SatScape

Ham Radio Deluxe

On-Line Predictions

Station Settings

Keplerian Elements Describe the Shape of the Satellite’s Orbit Sample of 2 Line NORAD Format ISS 1 25544U 98067A 07035.35732066 .00020205 00000-0 11892-3 0 5750 2 25544 51.6340 70.4350 0022217 166.2157 311.8909 5.77875086469 AO-51 1 28375U 04025K 07033.68080358 .00000014 00000-0 17267-4 0 7380 2 28375 98.1332 79.8042 0083077 230.1300 129.2564 14.40553747136

Orbit Shape

Low Earth Orbit

Molniya Orbit (Elliptical)

Pass Predictions

Local Horizon View

Getting Started Case 1 – Limited Equipment / Funds Case 2 – Automated Station

How Do I Get Started Dual Band HT 2m / 70cm Duplex Mode Arrow Type Antenna Tune Radio Know When the Satellite will Appear Aim the Antenna Listen for Signal Call Have a Helper Log the Contact!

Dual Band HT 2Meter FM 70CM FM Full Duplex Mode Speaker Mike Helpful

Arrow Antenna

Arrow Antenna & HT

Homebrew Your Own

Automated Satellite Station

System Tasks When Satellite is in Range Antenna Control Compute Satellite Position Send Azimuth Elevation to controller Steer the Antenna Array During the Pass Radio Control Compute Frequency Uplink Doppler Shift Downlink Doppler Shift Send Data To Radio

Automated Station Block Diagram

SAEBER Track Antenna Controller

Stamp II Micro-Processor Reads Voltage to Determine Position AZ EL Calculates New Position for Array Turn on/off Proper Relay to Move Array Loop and Do It Again Until Pass is Complete Sample of Program in Stamp II Processor

Stamp II Code Sample

Field Day Satellite Array

Contacts Other Hams Within Same Satellite Foot Print ISS Crew Members (ARISS Project) Digital Store Forwarding Messaging (Packet) APRS Via Satellite (Automated Position Reporting System)

Bill McArthur (KC5ACR) Operating NA1SS Commander ISS Expedition 12

Sunita Williams (KD5PLB) ISS School Contact

Mike Finche (KE5AIT)

Future Satellites “EAGLE” (Built by AMSAT) P3E (Built by AMSAT DL) High Earth Orbiting (Elliptical Orbit) Software Defined Transponder (Software Defined Radio) Linear Transponders, Digital P3E (Built by AMSAT DL) High Earth Orbit Test Bench for P5A Mars Mission Linear Transponders (Many Bands) Intelsat Geo-Stationary Available full time Full Time Access Emergency / Disaster Communications SuitSat II

WEB Links www.satscape.co.uk www.heavens-above.com www.amsat.org www.amsatnet.com www.rac.ca/ariss/oindex.htm

SUMMARY Look at Project OSCAR History Operating Modes Prediction Software Getting Started Other User of Amateur Satellites Future Projects

Questions?