Design & Implementation of Cube Satellite

Presented ByMd. Saifur Rahman

What is CubeSat ??• Dimension 10 cm x10 cm x10 cm• Weight < 1.33Kg• Power < 10W• Building cost < 8000$

In a word, small, miniature, fully functional satellite for remote sensing application and research purposes.

Problem StatementStructure & payload design of a CubeSat.Ground Station and receiving antenna design for CubeSat.Optimize cost of the Design in a CubeSat.Engineering aspects designed, tested and programmed in conjunction with CubeSat.Provide a stable and safe structure to support the payloads of a CubeSat for affordable research in the future.

Satellite Specification• Uplink Frequency: 437 MHz• Downlink Frequency: 440.5 MHz• Frequency deviation: 3.5 kHz• Modulation: FSK• Output power: 0.5 W• Bit rate: 9600 bps• Call sign: K-SAT• Packet format: AX.25 UI frames• Data payload per packet: up to 239 bytes• Active: during commissioning period - mainly over the

Europe, later also periodically sending housekeeping data in bursts after every 3-4 minutes

Satellite Architecture

Structural Design

Vibration, stress, effective shelving and access panel design analysis and optimization.

Specification ValueLength x Height x Width 10 x 10 x 10 (cm)

Weight 1 (kg)Structural Materials 7075 or 6061-T6 (Al)

Center of Mass Within 1” of Geometric Center

Rails Length 13.5 (cm)Operating Speed ~7.5 (km/s)

Operating Altitude 700 (km)Average Magnetic Field 30,000 (nT)

Structural Design Concepts

Different design concepts analyzed.Commercially available parts, manufacturing and assembly.Cost is the main design constrain.

Thermal AnalysisExtreme changes in temperature occur as the satellite revolves around the earth. Critical components in the system are sensitive temperature changes and require an independent heating or cooling solution.

Solar Flare

Copper Heat Sink

Attitude Control & Determination

ACDS controls the pitch, yaw and roll of the satellite based on the instant parameters the satellite is experiencing.Stabilizing the satellite is important for the communications and integrity of the circuits.

ACDS Design Concepts

Determination:Magnetometer.GPS.Accelerometers.Sun Sensor.

Control:Coils.Gyroscopes.Passive magnets.Spin Stabilization.

Ground Station Requirements

• Yagi antenna with gain more than 16 dBi, preferably a crossyagi

• Low noise preamplifier for 70cm band• Antenna rotator for both azimuth and elevation• Transceiver capable to receive 9600 bps packet• G3RUH-type TNC (e.g. Kantronics KPC-9216+) or

SDR with appropriate software (e.g. based on https://www.cgran.org/wiki/ESTCube-1Receiver)

• Packet data could be received also using a soundmodem program - AGWPE, MixW, Linux Soundmodem, MultimonNG etc

Telemetry Software Design

Telemetry Example• The number of satellite in NORAD database is

2013-021C and it has now following TLE-s.

• 2013-021C • 1 39161U 13021C 13127.51954931 -.00000050 00000-0 00000+0 0

17• 2 39161 98.1290 205.9903 0008586 231.4152 242.5727

14.68885660 27

• This SateTLE-s will be available via NORAD: http://www.celestrak.com/NORAD/elements/

Design Process• Attitude vectorial analysis and design• Space conditions analysis (thermal

phases, radiation, collisions)

• Structural prototyping and assembly of parts Develop and debug attitude control and determination program (written in C) for main CPU (BeagleBoard)

• Run physical tests on components Collisions testing environment Operating temperatures of circuits tests Magnetic and accelerations testing

The End