Abstract#

The Sentinel Bio+ project combines efforts from San Jose State University, San Diego State University, and the San Diego Space Institute. The goal is to create a constellation of satellites each equipped with a science payload. For now, the senior project team at San Jose State University is focused on creating a FlatSat, a bench testing configuration, that helps with testing of the design. The team is currently limited to one working FlatSat, which limits the amount of testing they are able to accomplish. With this project proposal the senior students at SJSU are hoping to receive funding that allows for multiple FlatSats to increase the productivity of the project.

Problem#

Satellites are complex pieces of technology that require rigorous testing before they are ready to be launched into orbit. This means that every subsystem within the satellite needs the proper tests, and appropriate integration needs to occur. Currently, the SJSU senior design team is limited to one FlatSat, which was student funded. This shared testbed creates a bottleneck within the project because it limits the amount of testing that can be done, thus leading to a limited amount of integration cycles that can be implemented and completed within the senior project timeline.

Solution#

The solution to this is to fund additional FlatSat testbeds, allowing for parallel testing. The additional testbeds can be dedicated to different subsystems within the team, allowing for more troubleshooting and faster turnaround times. A common function baseline can be created with the original FlatSat, and the additional ones can be dedicated to each of the engineering sub-teams. This allows for controlled integration reference while also allowing subsystems to progress without waiting on each other.

Novelty & Prior Art#

What already exists?#

FlatSat and hardware-in-the-loop testing are established approaches in spacecraft development. Relevant public prior art includes:

• NASA Lunar Reconnaissance Orbiter FlatSat, which used a FlatSat for subsystem, instrument, ground-support-equipment, and system-level integration testing.
• ESA CubeSat FlatSat, which demonstrates an open-access test configuration for CubeSat subsystem and payload testing.
• NASA Operational Simulator for Space Systems—NOS3, an open-source software environment for spacecraft software development, integration, testing, verification, validation, and mission operations.
• Hardware-in-the-loop and software-in-the-loop testing of the MOVE-II CubeSat, which demonstrates integrated testing of CubeSat subsystems including ADCS, EPS, and command-and-data-handling systems.
• NASA CubeSat Design Specification, which provides established guidance for CubeSat design, interfaces, testing, and mission success.
• MoonDAO's Satellite Payload and Secondary Education Project, which connects student-built spacecraft work with MoonDAO's educational and lunar-development mission.
• MoonDAO's Deployable Video Payload for Sounding Rocket, which emphasizes open hardware documentation and reusable space technology.
• MoonDAO's Lunar Open-source Rover Standard, which illustrates MoonDAO's interest in shared, open, reusable technical standards.

What is new about this project?#

This project does not claim that FlatSats or spacecraft integration testing are new. Its contribution is the creation of a low-cost, replicable, open two-unit FlatSat testbed for the Sentinel Bio+ student constellation.

The project will provide:

1. Two matching FlatSat configurations using commercially available components;
2. A complete bill of materials and assembly documentation;
3. A version-controlled common hardware and software baseline;
4. Parallel subsystem testing across multiple units;
5. Fault-injection and validation procedures;
6. A final validation report and reusable repository for MoonDAO and other student teams.

The specific new deliverable for MoonDAO is an accessible, documented, and repeatable integration-and-test package that can be reused by future community spacecraft projects.

Why not just use the existing work?#

Existing NASA, ESA, academic, and commercial testbeds demonstrate the value of FlatSat and hardware-in-the-loop testing, but many are mission-specific, institution-specific, proprietary, expensive, or not packaged for immediate reuse by MoonDAO contributors.

NOS3 provides a valuable software simulation environment, but it does not provide the physical COTS hardware needed for parallel electrical, communications, sensor, power, and subsystem integration testing. Existing FlatSat examples also do not provide the exact Sentinel Bio+ configuration, its student-oriented replication instructions, or its planned fault-injection and validation evidence.

Funding this project allows MoonDAO to receive a working physical testbed and reusable documentation during this quarter rather than only receiving a list of external references.

Honesty check#

The main contribution is a synthesis, integration, education, and open-documentation effort rather than a claim of completely new spacecraft-testing theory. The innovation is in combining low-cost COTS hardware, parallel testing, configuration control, student training, and an openly reusable deliverable tailored to MoonDAO's community.

This project does not claim to be the first FlatSat, the first CubeSat testbed, or the first hardware-in-the-loop spacecraft project.

Lunar Bridge#

The Sentinel Bio+ FlatSats will help develop the integration, telemetry, fault-management, and verification practices required for reliable spacecraft operations beyond Earth. By enabling multiple subsystems to be tested in parallel, the project increases the number of integration cycles that a student team can complete before advancing toward flight hardware. The open documentation and validation evidence can be reused by future MoonDAO satellite, rover, communications, and lunar infrastructure projects. This creates a practical training and testbed pathway from university-scale hardware development toward the reliable systems needed for sustained robotic and human activity on the Moon.

Community Standing#

I have attended several MoonDAO Town Hall meetings and reviewed MoonDAO's ideation materials to better understand its mission, community priorities, and project-selection process. I look forward to contributing the team's results and documentation to the MoonDAO community.

Reporting Schedule

The Project Lead will provide a brief progress update in MoonDAO's Discord progress channel every week. A detailed written report will be submitted every two weeks on project days 14, 28, 42, 56, 70, and 84. Each report will include completed milestones, expenditures, risks, blockers, test results, and the next planned activities. On day 90, the team will submit a final report containing the completed deliverables, repository link, validation evidence, final budget reconciliation, and any unused funds returned to the MoonDAO Treasury.

Benefits#

The benefit of funding this solution is that MoonDAO would receive completed documentation on how to replicate the FlatSat, along with test producers, validation efforts, and validation evidence. This means that MoonDAO, along with others in the scientific community, can utilize this design on future lunar technology-development projects. Additionally, by helping the students at SJSU fund their project, MoonDAO would be acknowledged during the final senior design review. This would strengthen the relationship between MoonDAO and the aerospace department at SJSU and would help open the doors to future collaborative efforts.

Risks#

The risks with this project proposal are component availability issues, software baseline divergence across units, and subsystem testbed configuration variances. In order to mitigate these risks, the team will be purchasing all FlatSat components at the same time to ensure the FlatSats are identical; this helps to eliminate the risk of variants. For the possibility of divergence across FlatSat units, a version-controlled repository will enforce the configuration-controlled baseline. All FlatSat units will be regularly configured to the same standards before subsystems start developing on their own testbed. These combined efforts will help to mitigate any risks of having the FlatSats being misconfigured or out of sync.

Component availability contingency: The team will verify supplier stock and pricing before purchase. If a listed component becomes unavailable, the team will first use an equivalent component with equal or better electrical and interface specifications. Any substitution will be documented in the bill of materials, approved by the Project Lead, and reflected in the wiring and test documentation. If a substitute exceeds the available budget, the team will reduce optional purchases and preserve the minimum two-unit functional demonstration. No budget increase will be requested during the quarter.

Objectives#

Objectives#

Objective #1: Make the FlatSat assembly completely replicable through controlled documentation.#

Key Results:

• By day 14, publish a complete bill of materials identifying every component, quantity, supplier, unit cost, and approved substitute.
• By day 30, publish wiring diagrams, interface maps, assembly procedures, safety notes, and configuration requirements.
• By day 90, release the complete documentation package in a public repository under CC BY 4.0.

Responsible: Entire team.

Objective #2: Complete and validate the power-distribution system on both FlatSat units.#

Key Results:

• By day 35, install and document the switches, fuses, converters, power-distribution boards, and electronic-load modules on both units.
• By day 45, verify the required voltage and current limits for each subsystem through recorded measurements.
• By day 60, correct and document any identified power-distribution faults.

Responsible: Sarah Boughton—EPS Lead

Objective #3: Establish reliable communications and telemetry between the FlatSat subsystems.#

Key Results:

• By day 50, install and configure the RockBLOCK modems, antennas, cables, and communication interfaces.
• By day 65, demonstrate at least three successful command-and-telemetry exchanges.
• By day 70, publish communication test logs documenting performance, failures, data-path issues, and corrective actions.

Responsible: Priam Moran—Communications Lead.

Objective #4: Integrate and validate the sensor and fault-detection system.#

Key Results:

• By day 60, install and test the current, voltage, temperature, light, magnetic-field, and GNSS sensors where applicable.
• By day 75, demonstrate that sensor data is collected, transmitted, and displayed correctly for both FlatSat units.
• By day 82, complete at least three documented fault-injection tests and record whether each abnormal condition was detected.

Responsible: Ian Catizone—ADCS/Software Lead; Mateo Zepeda—Thermal and Sensor Lead; Sarah Boughton—EPS Lead.

Objective #5: Maintain consistent hardware and software configurations across both FlatSat units.#

Key Results:

• By day 45, apply the same approved hardware and software baseline to both units.
• Track all configuration changes, substitutions, software versions, and test results in a version-controlled repository.
• By day 80, complete identical comparison tests and document whether both FlatSats produce consistent results.

Responsible:Entire team.

Objective #6: Complete system-level testing and demonstrate the working FlatSat units.#

Key Results:

• By day 45, demonstrate two assembled FlatSat units completing functional power-up, sensor readout, and communications or telemetry tests.
• By day 85, complete integrated power, communications, telemetry, sensor, and fault-management testing.
• By day 90, publish the final validation report, test logs, limitations, recommended improvements, and demonstration evidence.
• By day 90, provide itemized receipts for every funded purchase, reconcile all spending against the approved budget, release original software under the MIT License, and return all unused funds to the MoonDAO Treasury.

Responsible: Entire team

Non-goals This Quarter#

This project will not:

• Build or launch flight-qualified spacecraft.
• Claim that the FlatSats are ready for orbital or lunar deployment.
• Develop a complete satellite constellation or mission.
• Design a lunar habitat, lander, rover, or lunar surface infrastructure.
• Complete environmental qualification, radiation testing, vibration testing, or space certification.
• Develop commercial products or establish a company.
• Replace professional flight software, mission assurance, or regulatory review.
• Build more than the two proposed FlatSat test units.
• Develop new satellite components; the project will use commercially available hardware.
• Provide launch services, flight operations, or long-term spacecraft maintenance.

The quarter's scope is limited to assembling, testing, documenting, and demonstrating two ground-based FlatSat testbeds.

Team (Table A)#

Role 2: Mechanical implementation - Caleb Maslic

Role 3: Communications- Priam Moran

Role 4- ADCS - Ian Catizone

Role 5: Thermal - Mateo Zepeda |

Team Bios

Project Lead: Shanmuga Selven is an aerospace engineering senior with a minor in physics at San Jose State University, backed by an A.S. in Science & Mathematics. A veteran of multiple NASA L'SPACE academies and hands-on hardware testing, he spearheads orbital analysis and trajectory modeling for the Sentinel-Bio+ constellation. Armed with expertise in Python, MATLAB, spacecraft design, and cutting-edge AI/ML integration, Shan merges high-level analytical firepower with visionary leadership to push the absolute limits of space exploration.

www.linkedin.com/in/shan-selven-lab025162

Team Member #1: Sarah Boughton is a senior student at San Jose State University on track to graduate May 2027 with a bachelor's degree in aerospace engineering. Her previous academic background includes: AA in Quantitative Reasoning, AA in Communication Studies, and an AA in Humanities. She is now solely focused on applying her knowledge to aerospace engineering and how she can make an impact in the community. Her expertise includes: a strong understanding of structural analysis, advanced mathematics, and proficiency in C++, MatLab, Python and CAD.

www.linkedin.com/in/Sarah-Boughton-b17869407

Team Member #2: Caleb Maslic is a 4th year student at San Jose State University, studying Aerospace Engineering. With a mix of in class experiences and projects, such as L1 and L2 rocket design and builds, he has been able to apply engineering skills towards his current work of being the lead for the Mechanical subsystem for the Sentinel Bio+ project with SDSI. He is highly dedicated to using his skills and knowledge to further push the progress of space exploration. www.linkedin.com/in/caleb-maslic-105909295

Team Member #3: Priam Moran is an aerospace engineering student at San José State University with an interest in spacecraft systems and space communication technology. He completed engineering courses throughout all four years of high school, developing a strong foundation in computer-aided design (CAD) and computer-integrated manufacturing (CIM). He has continued expanding his technical knowledge at university and applies it through his senior design project, Sentinel Bio+. He is passionate about developing practical space technologies and gaining experience through collaborative, interdisciplinary engineering projects. https://www.linkedin.com/in/priam-moran

Team Member #4: Ian Catizone is studying aerospace engineering at San Jose State University with interest in GN&C and propulsion. He has developed his programming and prototyping skills along with strong analytical thinking which he is applying to the Sentinel Bio+ project on the ADC system, as well as the development of an NOS3 digital twin. He is eager to learn more about the process of developing space systems and to contribute to the advancement of space science.

https://www.linkedin.com/in/ian-catizone-66310a280

Team Member #5: Mateo Zepeda is a student at San Jose State University studying aerospace engineering, with a focus on space systems and physics. He has experience in using technical programs including CAD, general programming, and CFD. He is excited to apply these skills and expand his skillset as the thermal lead in the Sentinel Bio+ project. He hopes to continue to apply himself through impactful and challenging interdisciplinary space systems.

https://www.linkedin.com/in/mateo-zepeda-3b4a82441

Intellectual Property

Mixed

All project-created documentation, wiring diagrams, assembly instructions, test procedures, validation reports, and configuration records will be released publicly under CC BY 4.0. All original software code created under this proposal will be released under the MIT License. Vendor documentation, third-party libraries, pre-existing university materials, and restricted materials will not be copied into the repository; they will instead be identified with links and their applicable licenses. The final public repository will contain the complete MoonDAO-funded documentation and all original project code that the team has the legal right to release.

Timeline (Table B)#

Deadline for the project: End of Q3 - December 31

Budget (Table C)#

Arduino Portenta Core Hardware#

Breakout Board | $46.20 | 2 | $92.40 | Core FlatSat component- 1 per | | | | Subtotal: | $492.30 | |

Communications Hardware

9603 Iridium

SBD Modem | $140.00 | 2 | $280.00 | Core FlatSat component- 1 per | | Coaxial Cable U.FL to SMA | $5.84 | 2 | $11.68 | Core FlatSat component- 1 per | | 2J6033PGF

Iridium Certified Patch Antenna | $54.95 | 2 | $109.90 | Core FlatSat component- 1 per | | | | Subtotal | $ 401.58 | |

FDIR Sensor Suite

TSL2591 High Dynamic Range Light Sensor | $6.95 | 8 | $55.60 | Core FlatSat component- 4 per | | Adafruit

LIS3MDL

Triple-Axis

Magnetometer | $9.95 | 2 | $19.90 | Core FlatSat component- 1 per | | Adafruit SX1262 LoRa Radio

Module | $19.95 | 2 | $39.90 | Core FlatSat component- 1 per | | Adafruit

TCA9548A I2C Multiplexer | $14.95 | 2 | $29.90 | Core FlatSat component- 1 per | | u-blox

NEO-M8N

GNSS Receiver | $35.00 | 2 | $70.00 | Core FlatSat component- 1 per | | STEMMA QT / Qwiic Cable

Pack | $9.40

| 2 | $18.80 | Core FlatSat component- 1 per | | | | Subtotal: | 339.80 | |

EPS / Power Distribution

Toggle Switch

≥10A | $6.99 | 2 | $13.98 | Core FlatSat component- 1 per | | Inline Fuse

Holder | $7.99 | 2 | $15.98 | Core FlatSat component- 1 per | | Mini Blade Fuse Pack (low-amp) | $5.39 | 2 | $10.78 | Core FlatSat component- 1 per | | 12V DC-DC

Converter

Buck/Boost | $18.95 | 2 | $37.90 | Core FlatSat component- 1 per | | 5V DC-DC

Converter Buck | $21.95 | 2 | $43.90 | Core FlatSat component- 1 per | | 3.3V DC-DC

Converter Buck | $21.95 | 2 | $43.90 | Core FlatSat component- 1 per | | Electronic Load Module | $38.99 | 2 | $77.98 | Core FlatSat component- 1 per | | Breadboard /

Power

Distribution

Board | $8.49 | 2 | $16.98 | Core FlatSat component- 1 per | | | | Subtotal: | $261.40 | |

Integration & Test Hardware

Rev3 — EPS

telemetry MCU | $27.60 | 2 | $55.20 | Core FlatSat component- 1 per | | SparkFun Logic Level Converter Bi-Directional | $3.95 | 2 | $7.90 | Core FlatSat component- 1 per | | Solderless

Breadboard | $9.99 | 2 | $19.98 | Core FlatSat component- 1 per | | SanDisk 32GB microSD —

2-pack

| $17.87 | 2 | $35.74 |

Core FlatSat component- 1 per | | Hookup Wire

Set 16–22 AWG | $15.89 | 2 | $31.78 | Core FlatSat component- 1 per | | Heat-Shrink Butt Connector

Wiring Kit | $8.99 | 2 | $17.98 | Core FlatSat component- 1 per | | Acrylic / Wood Mounting Base | $20.00

| 2 | $40.00 | Core FlatSat component- 1 per | | | | Subtotal: | 208.58 | |

*All budgeting is to go toward FlatSat components.

| Arduino Portenta Core

Transactions (Table D)#