Status Report #1

MAE 435: Project Design and Management II

CubeSat Project

Old Dominion University

Virginia CubeSat Constellation

January 29th, 2018

Advisor: Dr. Robert Ash

Team: Robert Bossinger, Jordan Byrd, Zachary Campbell, Mariano Chacon, Charles Chiou, Avery Corbett, Thomas Crouse, Justin Hernandez, Westin Messer, Susannah Miller, Cody Steele, Joseph Vogel, Kimberly Wright, Wade Yeary

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Mechanical (completion 60%)

• Design (completion 75%)

• Objectives

• Deliver a completely fabricated and assembled CubeSat chassis that will house the stacks, containing electrical hardware and boards. Determine a hinge design for the drag brake payload, that will withstand the forces experienced during deployment of brake petals.

• Completed

• The chassis skeleton has been machined without screw or switch holes, which are currently being finalized. The drag brake hinges have undergone new design iterations and a design has been chosen and analyzed with Patran, a Finite Element Analysis (FEA) tool. The FEA analysis is currently being reviewed by Dr. Hou to determine validity/ accuracy.

• Issues

• The lead time for the hinge fabrication has been estimated with a reasonable timeframe of two weeks. The design team needs to ensure the hine FEA is completed in a timely manner, to ensure fabrication stays on schedule and allows a buffer time region, in the case something goes wrong.

• The electrical team needs to determine an appropriate size for the rail switches, before the chassis fabrication can be completed. The process of identifying sufficient switches could be time consuming, since permission from NanoRacks must be obtained in order to use a smaller switch, that will fit in ODU’s chassis rail.

• ADCS (completion 50%)

• Objectives

• Determine and control orientation of the CubeSat. ADCS is necessary to accurately measure density of the Earth’s atmosphere in Low Earth Orbit (LEO), optimal power generation, and drag brake deployment.

• Completed

• Specific tasks, that contribute to overall ADCS objectives, assigned last semester are in algorithm development. The projected completion of all algorithms align with the Midterm Status Report, at that point testing for all three tasks will be fully underway. These three tasks are Earth Orientation Vector, Albedo Sun Sensor Filtering, and Attitude Determination from Sun Vector.

• Issues

• The ADCS subject matter expert, who developed entire ADCS component structure, is no longer an available resource. There was no information turnover, so the baseline for which ADCS was to be build upon is virtually nonexistent. Some completed software was found on the shared constellation drive, but it is not enough to move towards delivering a completed, tested, and fully functional system. In response, contact has been made with a graduate student at ODU to aid in the completion of the team objectives. Also, industry support has been presented to the team and a technical summary detailing what has been completed has been sent to the company. Rescoping of the ADCS systems remaining tasks will need to be re-evaluated once the new subject matter expert has had time to review the pertinent information regarding the system.

• Thermal (completion 70%)

• Objectives

• Determine the various CubeSat heat sources and determine the effects it will have on the functionality of the satellite, during the orbital lifetime. The thermal analyses performed will identify the temperature tolerance range, the satellite can withstand and still function properly, within the parameters of the mission.

• Completed

• The temperature range the CubeSat can withstand, while still functioning properly has been identified, 150 C to -80 C. This range of values was determined through Systems ToolKit (STK) software. The temperature range data will assist in the determination of the optimal deployment time.

• Issues

• There are no current issue in this subteam.

• Orbital (completion 70%)

• Objectives

• Determine and model the expected orbital path of the CubeSat, for the duration of the mission. This model will allow for the determination of the best-case-scenario deployment window, ensuring the satellite will be preferable positions/ locations to receive maximum sunlight and solar radiation.

• Completed

• An orbital model has been created, simulating and tracking the expected flight path of the CubeSat. The reference frame of this analysis was the International Space Station (ISS). This information will become crucial when calculations and simulations are run to determine the ideal deployment window, from NanaoRacks. This time window will ensure maximum solar energy/ sunlight exposure for the solar panels on the satellite. This information will then be presented to NASA to provide justification for requesting a deployment time/ window.

• Issues

• There is a lack of knowledge on power distribution simulations in STK, so the team will meet with the project advisor to discuss solutions and determine a plan to move forward and produce desired orbital data.

Electrical (Completion: hardware design – 80%, software development – 40%)

• Objectives

• Create a custom port of the µC/OS-III RTOS for our chosen MCU. Develop an adaptive data management and housekeeping system. Develop an adaptive, multi-staged, total system failsafe diagnostic and digital triage system. Integrate the OS with ADCS algorithms. Design and fabricate a PC104 stack comprising of processing, GPS, radio, UHF antenna, and GPS antenna boards. Auxiliary systems in the PC104 stack include: burn wire mechanisms, deployment confirmation systems, EMI and radiation shielding, power production and storage, and hardware fail-safe systems.

• Completed

• The port of µC/OS-III has been completed in addition to the task block framework. The operational order and frequency of tasks has been decided, and will need to be optimized once initial full system testing begins. PCB designs and schematics are finalized and will be sent off for production after the boards are optimized for COM.

• Issues

• Complications involving the other universities and unmotivated individuals on the ODU E-team.

Virginia CubeSat Constellation (VCC)

• Licensing (completion 20%, generous estimation)

• A major factor determining the constellation’s ability to fly is obtaining the appropriate licenses, through the Federal Communications Commission (FCC). After initial communication with FCC representatives, it has been determined that the VCC will pursue an experimental license to perform the constellation’s mission. Generally, the process of applying for and obtaining an experimental license ranges from one to five years. Given the current timeline of the project, there are some major concerns about the ability to obtain a license in time for delivery.