phases

Ashiqur Rahman • Michael Everett • Ahsan R. Choudhuri • Bill Tseng

CENTER FOR SPACE EXPLORATION AND TECHNOLOGY RESEARCH (cSETR)

THE UNIVERSITY OF TEXAS AT EL PASO

Preface

Orbital Factory II (OFII) is a 1U CubeSat which will be launched into a geostationary transfer orbit (GTO)

onboard a United Launch Alliance (ULA) Atlas V rocket. OFII was awarded this launch opportunity for

winning first place in ULA’s CubeCorps CubeSat design competition. OFII will study additive

manufacturing in microgravity. This will be accomplished using a small printer which will simulate the

repair of a solar array by printing an electrically conductive trace between a simulated tear on a solar

panel. OFII’s secondary experiment is the Electron-Emitting Film (ELF) and Surface Charge Monitoring

(SCM). This experiment will study the feasibility of using ELFs to manage vehicle charge by emitting

electrons that are collected on the spacecraft as it passes through the highly radioactive Van Allen belt.

The SCM will measure changes in the charge of OFII’s structure. OFII’s last experiment is an

experimental S-band patch antenna provided by Lockheed Martin Space Systems. This antenna will go

through qualification testing at UTEP before being tested in GTO. Due to the extreme radiation

encountered in the Van Allen belts, OFII will test a method of radiation mitigation using a thick-walled

Titanium chassis. The nominal mission duration is five days, which will allow for OFII to complete its

experiments and downlink data before it succumbs to radiation damage. Data will be downlinked to a

network of ground stations via UHF and S-band, with UHF serving as the primary frequency.

Communication System Overview

Chassis Assembly

Orbital estimation

Launch not yet manifested

Prior Atlas V GEO launches analyzed

Averaged orbital data from spent Centaur stages:

Apogee: 35,065 km

Perigee: 3,978 km

Inclination: 21.4 degrees

Period: 11 hours, 31 minutes

Orbital parameters used in STK to perform analysis of

our mission

Motherboard

Electrical Power

System

Transceiver

Radiation

Dosimeter

UHF

Antenna

Printer

Patch Antenna

Solar Panel (x5)

On-board Payload

✓Single axis 3D printer

✓Experimental S-Band patch antenna

✓Surface charge monitor (SCM)

✓Electron emitting film (ELF)

✓3D printed chassis / radiation shield

✓Radiation dosimeter (tentative)

Mission Success Criteria

1.OFII shall survive launch and deployment

2.Electrical continuity shall be measured across printed trace

3.Ground stations shall receive at least (1) S-band transmission

4.Surface potential shall be measurable in a high radiation

environment

Orbital Factory II: The Challenge

1.GTO will take us through the Van Allen radiation belts

2.Trapped particles damaging to electronics

3.STK used to model Van Allen belts and estimated radiation

dosage over 5 days

Phase 1: Launch

Launch date: TBD (Late 2017, early 2018)

Vehicle: Atlas V (Version TBD)

OF-II powered off during all launch

Phase 2: Primary Satellite Separation

Approx. T+ 105 minutes after liftoff

Approx. 8,970 km altitude

OFII remains powered off

Phase 3: Deployment

Approx. T+ 210 minutes after liftoff

Approx. Altitude: 29,000 km

Deployment from ABC

EPS immediately power on

OBC boot up

Phase 4: First Communications Attempt

T+45 minutes from deployment

Approx. Altitude: 32,600 km

First S-Band communication attempt

VHF Antenna Deployment & Transmission

Repeated at Regular Intervals

Phase 5: Housekeeping

Approx. T+ 7 hours from deployment

Approx. Altitude: 14,000 km

Exit outer Van Allen belt

System Checkout

Mission TimelineOF-II Payload & Mission objective

Internal block diagram of Comm System

OF-II signal reception

Project/Thesis Title Here

OF-II will have access to a network of ground stations in order to provide global coverage. A Ground

station will be built and funded by UTEP. Also, we will be renting ground system from commercial

companies who provide ground station coverage in many places around the world. Our analysis and

calculations tell us the actual footprint of OF-II and allow us to select proper ground system locations.

Figure : Current ground system facility available for OF-IIFigure : OF-II footprint analysis

A CUBESAT COMMUNICATION SYSTEM DEVELOPMENT FOR GTO MISSION

Ashiqur Rahman • Michael Everett • Ahsan R. Choudhuri • Bill Tseng

Center for Space Exploration & Technology Research

The University of Texas at El Paso

Through Orbital Factory II we have:

• Learned about the systems engineering process

• Gained hands-on experience in hardware development and procurement

• Practiced satellite design and operation

• Obtained mentorship from career Lockheed Martin engineers

OF-II professional development Acknowledgement

Utep Cubesat Team

Mr. Michael Everett

Industry Partners:

Lockheed Martin Space Systems

United Launch Alliance

Tyvak

Presently no CubeSats launched beyond LEOAnalyzed 7 prior Atlas V GEO launches

GTO considered a viable graveyard orbit

Communications attempts will be made mostly from

perigee