ARMADILLO: Subsystem Booklet Mission Overview The ARMADILLO mission is the Air Force Research Laboratory s University Nanosatellite Program s 7 th winner. ARMADILLO is a 3U cube satellite (cubesat) constructed at the University of Texas by the TSL (then the Satellite Design Laboratory, or the SDL) with three payloads to preform different science experiments: the FOTON, a 2 way GPS receiver used to preform radio occultations with GPS satellites through the ionosphere; the PDD (piezo-electric dust detector), a device used to characterize submillimeter debris by impact in Low-Earth Orbit; and the retroreflector, a device to be used in combination with NASA Ames in laser-ranging experiments. As the launch date approaches, the ARMADILLO team is focused on creating and maintaining an extensive operations architecture to support the satellite s launch, finishing development of a satellite telemetry GUI, extensive hardware and software verification testing, and verification of the satellite and ground systems through link and power budgets, and other tasks. Subsystems Work within the TSL on the ARMADILLO mission has been divided into six subsystems: 1. Communications (COM) 2. Attitude, Determination and Control (ADC) 3. Guidance, Navigation and Control (GNC) 4. Electrical Power Systems (EPS) 5. Thermal Protection Systems (TPS) 6. Structures (STR) A description of the role of each subsystem within the overall mission as well as some of the skills deemed useful for each subsystem can be found below.
2 Communications (COM) The Communications subsystem is focused on the interaction between the spacecraft and UT satellite ground station. We focus on ground station operations, such as setting pass schedules for spacecraft that we deem interesting including Falcon-Sat and FO-29, training for the eventual operation of the ARMADILLO spacecraft, as well as the maintenance and improvement of the ground station hardware itself. In the past, the Communication subsystem has been responsible for the ARMADILLO link budget, as well as training TSL personnel in the operation of the ground station. In the future, COM will oversee the creation/improvement a new ground station when the aerospace department moves out of WRW. COM will also be responsible for establishing the communication requirements for future spacecraft and based on those constraints design a system including but not limited to: spacecraft radio, spacecraft antennas, ground station, and ground station antennas. COM will be responsible for the testing of the individual components and the system as it is integrated. Linux Python Radio-frequency proficiency Soldering Wiring Machining Amateur Radio Technical writing Research Ability
3 Attitude Determination & Control (ADC) The ARMADILLO ADC team focusses on controlling the attitude (pointing mode) of the ARMADILLO spacecraft. Currently, the goal of the ADC subsystem is to ensure that all components of ARMADILLO s attitude control system function correctly and can operate manually or automatically as needed. ARMADILLO primarily uses a set of reaction wheels to rotate the spacecraft with three-axis control, complimented by a set of magnetic torque rods to unload momentum from the reaction wheels as needed. The code for the flight software has already been written, and requires testing and verification before flight. In order to do this, the team works with an attitude simulation program named StarBox, designed to run different simulations of the satellite given inputs of starting orientation and spin. Looking forward, this semester will involve working with a copy of the ARMADILLO flight computer to analyze the attitude control software. Further work on the StarBox simulator will be done to ensure that it accurately represents what is on the flight software. Once the simulator is determined to match the flight code, the team will shift focus to the simulation of attitude during in-flight science. This includes analyzing the limits on allowable maneuvers while moving into and out of eclipse, as well as determining power generation at different spin rates. C++ Linux Python MATLAB Aerospace upper division classes (space track) Experience with microcontrollers Computer hardware experience Quick learning skills
4 Guidance, Navigation, and Control (GNC) GNC answers the question: Where is the satellite? by developing software to support a satellite s ability to be guided, navigated, and controlled from the ground station. GNC was created last semester in effort to complete a program that provides the position calculations for the satellite s data. This includes calculating values in different reference frames and comparing the downlinked data to what is predicted by the U.S. Air Force s Joint Space Operations Center (JSPOC). Moving forward, the team will provide research utilizing a GPS receivers along with small computer hardware to aide in the team s understanding of GPS for future missions. We are looking for students of any background committed to learning and with an interest in space. If you do not have knowledge on everything on this list of desired skills but you are willing to learn, let us know! Python C++ Scientific Toolkit (STK) Amateur Radio Circuitry Computer hardware/controls Orbital Mechanics background knowledge Strong problem-solving skills
5 Electrical Power System (EPS) This team s primary concern is ARMADILLO s Electrical Power System (EPS). Our goal is to monitor ARMADILLO to ensure all components receive sufficient power to conduct basic operations, such as attitude control and radio communication, as well as conduct scientific experiments. Our responsibilities also involve mapping the power distribution within ARMADILLO and testing various components of the satellite to ensure quality performance. Ongoing work is centered around ARMADILLO s EPS and ascertaining power generation under certain operating conditions. Note: These skills are desired, but not required. A significant portion of participating in TSL involves learning new skills and we are more than glad to train new members in these areas. C++, Python Soldering Wiring Amateur Radio Technical writing Ability to work independently
6 Thermal Protection Subsystem (TPS) The Thermal Protection Subsystem is responsible for identifying thermal constraints for ARMADILLO and modelling the thermal conditions that the satellite will experience once in orbit. TPS was established as a stand-alone subsystem in the Fall of 2017, and over the past semester we have researched how the materials used on the satellite affect the absorption and emission of heat in space. We have also started modelling single-node and multi-node heat transfer cases in MATLAB. This semester we plan on refining our MATLAB models, using professional software packages to model more complex thermal systems, and working through design problems presented to us by NASA s JPL to be better prepared for future missions. MATLAB ANSYS Thermal Modelling Other CFD or Thermal Modelling Experience Experience using Thermocouples Experience using IR Cameras Coursework: Thermodynamics Heat Transfer
7 Structures (STR) The ARMADILLO Structures team is responsible for creating a full structural model of the ARMADILLO cubesat, as well as conducting both static and dynamic analyses on the generated model. So far, work on the Structures team has consisted of using ANSYS software to generate load cases and mesh models, while analyzing previous work conducted by former members of the lab, including old Solidworks models and ABAQUS analyses. In addition, we have trained other members of the lab in conducted structural analysis through ANSYS. Moving forward into new projects, the Structures team will likely be responsible for assisting with the design of the main spacecraft bus, including analyzing payloads to ensure they will survive the anticipated vibrational loads associated with launching into space. In addition, Structures members will likely gain significant experience in Solidworks modeling, structural design, and applying classroom techniques and knowledge to real-world stress analysis scenarios. ANSYS Medium Proficiency SOLIDWORKS Medium Proficiency CES EduPack Medium Profeciency (ASE 324L) Rapid prototyping experience Soldering Machining Proficient in Solid Mechanics Basic understanding of Structural Analysis Technical writing Teamwork skills Patience