Modular Nanosatellites as Amateur Radio Communication Platforms
Funded by the
New Hampshire Space Grant Consortium
Gus Moore; Todd Kerner, KB2BCT; Amish Parashar, KE6EZM
Project Concept
• Modularity by Design
• A functional bus module providing Power, Control, Communications
• Platform for Single-Purpose Research
• Compatibility with other University Programs
• Incremental Development
Evolution of DARTSAT
“Student Initiated, Student Designed, Faculty Mentored”
• Conceived Fall ‘99 as Amateur Radio Communications Satellite
• Desired Experimental Capabilities
“A Modular Approach
to Space Access”
CubeSat Program
• Stanford / CalPoly SLO providing opportunity for Thayer School’s Satellite Design Program
Establishes standards for design
DARTSAT Specifications
• 10 cm cube pre-release, < 1 kg
• 1 year functional life
• Amateur radio communication
• < $10,000 System Bus
• Capability to support a wide variety of experiments at any time
DARTSAT Functions
• CPU– FM repeater (J-mode)– DTMF control– Analog Measurements– Morse Code ID
• Data Acquisition– Temperature– Solar Cell Power– Battery Status– Magnetic Fields (Orientation)
Radio Specifications
• Receiver: 144 MHz uplink– Motorola MC13136– FM, 1 uV sensitivity, 5 kHz bandwidth– 3.8 VDC, 50 mA Operation
• Transmitter: 440 MHz download– Motorola MC13176, RF2117 Amplifier– FM, 125 to 500 mW RF Output, 5 kHz BW– 3.8 VDC, 500 mA max operation
Antennas •Perpendicular Dipoles for Transmitter & Receiver
•0 dB Gain
•Omni directional since satellite is not stabilized
•Using circularly polarized, high gain antennas on ground
•Antenna deployment once space borne
Unique Challenges• Wide Temperature Oscillation
-40 to +50 C
• Limited Power • Physically small package
– SMT all parts if necessary
• Extreme Vibrations high spin rates not stabilized
• Radiation Issues little mass protecting the circuitry
Testing DARTSAT
• Conducted at Lockheed / Sanders– Temperature– Vacuum– Vibration– Electrical Interference– Charging Case– Radiation Hardness
DARTSAT Status• Satellite Design Complete
– Radios– Mechanical– Power– Control
• Prototype complete – January 2001• Testing – February 2001• Flight unit – March 2001
Conclusions
• New student program, inaugural to Dartmouth Space Programs
• Provides a link between Amateur Radio and Academic Communities
• Future– Standardized Bus Plug and Play Science
Experiments– Constellations Low cost, large area
communications