QIKCOM

RE-CONFIGURABLE TRANSPONDER MODULE

Michael Segalla and Cole Skinker Advisor: Bob Bruninga AIAA YPSE Conference November 7, 2014



Problem Background

Automatic Packet Reporting System Protocol (APRS) is the primary communications protocol used by USNA satellites  With long development time, the response time for short fuse launch opportunities is limited  USNA only has one APRS satellite in operation currently 2

Slow Development Time

 PCSAT: communications satellite, 4 years to design and deliver for launch  Still operational  PSAT: communications CubeSat,  Time to deliver: ~6 years  Currently in work – manifest 2015  PCSAT2: communication payload, 2 years, attached to ISS  Returned to Earth 3

Automatic Packet Reporting System (APRS)

4

Host Satellite Opportunity

 A company has offered to house a USNA payload on a host satellite  Host satellite provides:  Power  Thermal control  Attitude determination system  Location for mounting interface

Requirements: Host

Voltage

Host Requirements

28V Temperature Range -20 °C - 60°C Housing Structure Size No larger than 4” x 6” Communications Reliable dual-antenna deployment system 6

Requirements: USNA

USNA Requirements

Users ~per minute 6 Packets ~per pass 51 Operational Availability Dependent on host specs Thermal Control : From Host S/C Host provides Temp Control within Min / Max Range Delivery Lifetime Reliability confidence

Schedule

Threshold 29-Dec 5 months 90 Objective 15-Dec 4.5 months 90

QIKcom Objectives

 Produce a transponder for Amateur Satellite Service within 5 month period  Provide an on-board beacon to actively notify wilderness terrestrial amateur radio users in North America when satellite is available APRS Integrated Network 8



Solution

USNA shall combine following COTS and self-designed components to produce module   

COTS:

MT-TT4 transponder: Micro-Amp 3 power amplifier: necessary to boost antenna power Mictro-Trak 8000 FA communications beacon: operates on terrestrial frequency, notifies users of satellite overhead  

Designed components:

Antenna deployment board EPS regulating board EPS Board 9

Concept of Operations

Beacon notifies users when QIKcom is overhead on terrestrial frequency.

Users tune to space frequency QIKcom Transponder module 10

Transponder module placed inside interface structure Module placed on NovaWurks Satellite Satellite positioned in launch vehicle Launch vehicle proposed take-off: March 2015 11

NuvaWorks Satellite deployed from ISS into 4-month mission orbit Launch March 2015 Rocket Payload rendezvous with ISS 12

System Overview

   Electrical Power System: 28 Volts supplied by host spacecraft Attitude Control: Host satellite orients satellite Thermal Control: -20 °C ↔ 60 °C Components assembled together on working board 13

Electrical Power System

Power Budget Power Budget Load Beacon (Standby) Beacon (TX) MTT4 (TX-users) MTT4 (TX-Telemetry) MTT4 (RX) Power Amp (TX) Total Operating Voltage 12 12 5 5 5 12 I pk (mA) 15 1000 280 280 45 1000 Duty Cycle 98.3% 1.70% 1.7% 4% 100% 10% I avg (mA) 28V I pk (mA) 28V I ave (mA) 14.75

17 4.8

11.2

45 100 7.14

476.2

55.6

55.6

8.93

476.2

1079.6

7.02

8.1

0.95

2.2

8.93

47.62

74.8

PCB Board Design 28 V - Peak Power (W) 28 V – Average Power (W) 30 2.1

Power provided by host bus. P avg of 2W consistent with 1U CubeSats, however all is dedicated to telemetry rather than other subsystems 14

Telemetry and Link Budget

Frequencies ITU Emission Designator Antenna

145.825 MHz - 4 Watt - AX.25 Telemetry downlink 16K0F1D, FM, 1200-9600 baud AX.25 data rate Cross polarized 1/4 wave whips

Power transmitted

6 dBW

Transmitter Gain Receiver Gain Space Loss at max range of 3000 km Computed Receiver Power RX threshold Margin at horizon for Oscar class sation Margin for hand-held omni-antenna

0 dB 15 dB -145.5 dB -127.5 dBW -146 dBW 18.5 dB 3.5 dB

TT&C and Downlink Operations

United States Naval Academy Mission Downlinks Amateur Radio Operators 3.5 dB sufficient margin for any amateur operator to communicate with QIKcom if within view 15

Antenna Deployment System

  Orthogonal dual antennas Lone resistor connected with fishing wire   Requires consistency: 50 successful tests for confidence Stacked housing Antenna deployment system 16

Thermal and EPS Sensors 5 Sensors: • • • • 2 Thermistors located on MTT4 and power amplifier, monitor safe operating temperatures 1 Voltage and 1 current sensors to monitor input from host bus 12V sensor to monitor proper regulation of power to power amplifier and beacon Tests completed to date: • Thermistor Calibration 80 60 40 20 0 -20 -40 -60 0  200 Recent test: Thermistor Calibration 600 800 17

CONCLUSIONS

18

Summary

Host Requirements

Voltage Temperature Range 28V -20 °C - 60°C Housing Structure Size Communications No larger than 4” x 6” Reliable dual-antenna deployment system  COTS and USNA components combined in rapid manner  Turnaround of 5 months achieved  Reduced lead time by 1/4 of previous comparable USNA satellite (PCSAT2)  Satellite enthusiasts notified when satellite overhead  Link budget indicates beacon sufficient

Parameter met?

Yes Requires Testing Yes Requires Testing 19

Future Schedule

Integrate PCB chip Test (Vibration / Thermal) Delivery (Dec. 29 th ) Launch (March) 20

Acknowledgements CDR Robert Bruninga, USN (ret.) Assistant Professor Jin Kang

Thank you for your time Questions?