OUR DESIGN

ENGR 490 (ME450 / MSE 480 / EECS 498) TEAM 6

B. Della Mora, P. Johnson, Z. Ni, A. Okorom, B. Richer, D. Samuel

Tethered “Pico” SatelliteSECTION INSTRUCTOR

Brian Gilchrist

SPONSOR

MiTEE

Student

Team

VALIDATIONPROJECT DESCRIPTIONThe MiTEE student team is researching

electrodynamic tethers for maintaining the orbit of

small satellites. The goal of our project is to design

both a picosatellite to conduct electrons for the

MiTEE 1 mission and a one-meter long boom

deployment mechanism. The satellite will be used to

gather data about the earth’s magnetic field for future

missions. Our picosatellite and deployment system

will be used in conjunction with the MiTEE team’s 3U

CubeSat and is constrained to a volume of 0.75U.

Our project illustrates a design for the picosatellite

itself and a boom deployment mechanism that will be

used in the MiTEE 1 mission in 2017.

Requirements Engineering Specifications

Meet NASA

standards

• Qualify to NASA GEVS

• CubeSat Design Spec[2].

Complete circuit for

thrust

• Minimize surface resistance

• Potential drop <2%

• Withstand 400V bias

• Boom insulated from

ionosphere

Minimize volume • Picosatellite, boom, and

deployment mechanism fit

within 0.75 U in CubeSat

Minimize mass • Picosatellite mass under

270 grams

• Center of mass within 1 cm

of attachment point

Function in orbit for

6 months

• Power source independent

of CubeSat

• Provide energy for entire

orbit

Data measurement • Tri-axis magnetic field

measurements

Communication • Wireless communication

• Omnidirectional 20-meter

range

Boom Deflection • Boom deflection <5 degrees

from CubeSat axis

Propulsion

provided by

electrodynamic

tether

Goal of MiTEE

project – two

tethered

picosatellites[1]

CubeSat with

deployed

picosatellite

(not to scale)

The stress-strain data allowed us to calculate the minimum storage

radius of the boom and use real material properties in our simulation.

We would like to express our gratitude to the following groups and individuals for their assistance and support with our project:

Prof. Mihaela Banu, Charlie Bradley, Tim Chambers, Wesley Chapkin, Dejiu Fan, Forrest Research Group, Prof. Brian Gilchrist, Prof. Rachel Goldman, Prof. Anthony Grbic, Prof. John Heron,

Aaron Lamoureux, Seungku Lee, Michigan Hybrid Racing, Miniature Tethered Electrodynamic Experiment Team, Zhiyuan “Hugh” Ni, Brendan Patterson, Daniel Shriver, Shtein Research

Group, Sodano Research Group, Student Space Systems Fabrication Laboratory, Prof. Alan Taub, Van Vlack Undergraduate Laboratory, Prof. Pete Washabaugh, and Ziwei Zeng.

Radiation pattern of the antenna

showing directional dependence

of the strength of the radio wave.

Low reflection coefficient around

2.4GHz represents high antenna

efficiency.

Our picosatellite (left) will deploy one meter from the MiTEE CubeSat on our fiberglass boom (right).

Boom

alignment

piece

Mechanism wall

Spool for boom Mechanism container

Boom

attachment

piece

AntennaPads for

electron

collection

Glass-

covered

solar cell

Using Abaqus to run a dynamic model of CubeSat attitude

adjustment, the boom deflection was calculated. We

determined that the deflection of a one-layer fiberglass

boom would be within engineering specifications.

Parameters Value UnitReceiving antenna gain 3.3 dBFSPL -66.25 dBPolarization Loss -3 dBPointing Error -3 dBEmitting Antenna Gain 3.3 dBTransmission Line Losses -2.5 dB3dB Margin -3 dBLink Budget -71 dBSensitivity -101 dBmMaximum RFout 0 dBmSurplus 30 dB

Link Budget for inter-satellite communication.

Communication/Electronics

We developed two designs based on tape

springs. The booms flatten and can be

rolled up in the deployment mechanism for

storage. They will be made of fiberglass

fabric and a thermoplastic polymer.

REFERENCES

[1] “MiTEE.” – Miniature Tether Electrodynamics Experiment. The University of Michigan, n.d. Web. 21

Jan. 2016

[2] Lee, Simon. CubeSat Design Specifications. Tech. San Luis Obispo: California Polytechnic State

University, 2014.

Circuit diagram for the electrical

components - Arduino microcontroller,

HMC5883L magnetometer, and

XBee RF module.

Boom Structure

Solar Cell Configuration

Communication

Power Generation

Energy generation with and without glass covering on solar cells.

Conductive indium-doped tin oxide (ITO) and fluorine-doped tin oxide

(FTO) glass coatings were also examined.

Deployment Mechanism Layout of Picosatellite

Using a MATLAB model to calculate the power and energy generated over the

course of one orbit, we were able to determine the required solar cell area.

Face-to-FaceBack-to-Back

Boom