a cubesat communication system development for … · orbital factory ii (ofii) is a 1u cubesat...
TRANSCRIPT
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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