Publication Date

Spring 5-5-2023

Document Type

Student Project

First Advisor

Fonseca, Benedito

Degree Name

B.S. (Bachelor of Science)


Department of Mechanical Engineering


The Jet Propulsion Laboratory (JPL) of the National Aeronautics and Space Administration (NASA) aims to develop a sensor network for the International Space Station (ISS) to ensure a comprehensive understanding of air quality within the station. The accumulation of carbon dioxide (CO­­­­­2) can lead to cognitive impairment, headaches, and potentially dangerous situations at high concentrations. Monitoring air content at the ISS is critical to maintaining a healthy environment for crew onboard. Exposure to harmful gases causes negative side effects that make crew sick, which may interfere with their responsibilities. CO2 is a gas that should be monitored because of the side effects caused by prolonged exposure, such as nausea, vomiting, and headaches. Monitoring CO2 content would help avoid negative side effects of CO2 exposure and improve ISS crewmembers’ quality of life.

This project builds on previous senior design projects by enhancing the firmware and hardware of the sensor modules to support the collection and transmission of real-world data. The graphical user interface (GUI) functionality was improved to support new sensors and a network of more than one sensor module.. The design of housing and mounts enables the replication of the ISS’s layout in NIU's facilities, and the creation of an automated breathing simulator supports test automation.

No hard budget cap was specified by JPL, but the previous year's senior design project had a budget of $17,721.99. The expended budget for this year's project, excluding JPL's in-house CO2 sensors, was $612.39, with most expenses allocated to the automated breathing simulator’s high-pressure valve.

Future work on the breathing simulator could further enhance the simulation of multiple human breathing patterns and enable the network to operate with a wider range of sensors.

If air content and flow data is collected at different locations in the ISS, crew can use this information to better understand trends in the air content which would help them maintain healthy air quality. Air CO2 content can be monitored by collecting data with a wireless CO2 sensor network and displaying this data in a digestible form at a dedicated base station computer. This is the fourth iteration of a proof-of-concept wireless CO2 sensor network system proposed by NASA JPL, now with added support for airflow measurements. The current system features a protocol for framing data for wireless transmissions, fully programmed microcontrollers to get data from sensors to the base station, and a GUI to display CO2 data and airflow data from multiple sensor modules.