BLiSS Bloom Box: Algae-Based CO2 Scrubber for Lunar Habitats

As part of the Bioastronautics and Life Support Systems (BLiSS) student team at the University of Michigan, I spent the 2023 to 2024 academic year designing, building, and testing a prototype life support system for a potential future lunar habitat, in partnership with Collins Aerospace, RTX, and NASA.

The system, called the Bloom Box, uses algae photosynthesis to scrub carbon dioxide from a crew habitat and regenerate oxygen, mimicking Earth's natural carbon cycle in a controlled engineered environment. Long-duration space missions face a critical challenge in managing atmospheric CO2, and conventional physicochemical solutions such as lithium hydroxide canisters and Sabatier reactors consume expendables and struggle to scale. The Bloom Box explores a bioregenerative alternative: a closed-loop system where algae do the work.

The 14-member team followed a full aerospace systems engineering lifecycle, progressing through SRR, PDR, CDR, and FRR design reviews with direct technical oversight from Collins Aerospace, RTX, and NASA engineers. The prototype achieved 12 to 26 percent of theoretical CO2 scrubbing efficiency, a strong result for a first-generation biological system. The system had three major subsystems: MoMS, responsible for algae health, nutrients, pH regulation, and lighting; HIH, responsible for mechanical integration, fluid routing, and gas delivery; and PCI, responsible for sensors, microcontrollers, and data acquisition.

My Engineering Contributions

I served on the Habitat Interfaces and Housing (HIH) subteam, responsible for the structural frame, fluid routing, CO2 injection system, and hardware mounts. My core technical contribution was redesigning the CO2 inlet interface to improve gas distribution across the reactor volume.

The original design caused uneven CO2 delivery, resulting in localized saturation, backflow, and poor gas transfer efficiency with the algae culture. I redesigned the inlet to split flow evenly across four spargers using integrated conical diffusers, then iteratively optimized the geometry using ANSYS CFD simulations at a flow rate of 30 L/min. The final design reduced backflow by 40 percent and significantly improved flow distribution uniformity, directly improving the mass transfer efficiency between gas and culture that drives the system's scrubbing performance. This component, the CO2 inlet interface, was also one of the two parts selected for evaluation in the VR testing sessions, making it central to both workstreams.

VARISS: XR Research Workstream

In parallel with the hardware work, I led an independent research initiative called VARISS (Virtual and Augmented Reality in Space Systems), commissioned directly by Collins Aerospace to investigate whether extended reality tools could improve the MBSE design process.

I designed and ran four structured CAD sessions using Siemens NX in VR, with two participants working in VR and two using traditional CAD as a control group. Participants completed structured feedback questionnaires after each session, covering spatial understanding, editing capability, measurement tools, and collaborative effectiveness.

The findings showed genuine and specific benefits. VR significantly enhanced spatial understanding: participants reported a far more accurate intuitive sense of scale and component geometry compared to a 2D screen, which matters when evaluating assembly fit for complex hardware. The VR drawing tool proved effective for collaborative design reviews, allowing engineers to sketch connections and communicate design intent in real time. One participant resolved a design conflict in under five minutes using VR that would have taken substantially longer through traditional methods.

However, the investigation also identified clear limitations. There were no extrusion, surface fill, or hole-cutting tools available in the VR environment, forcing engineers to return to traditional CAD for any actual design work. Undo functionality for the drawing tool was also poor. The conclusion was that VR in its current state functions best as a review and visualization adjunct rather than a primary design environment, and that its full integration into MBSE workflows will require purpose-built software with robust editing capabilities.

I documented all findings in a formal technical memorandum delivered to Collins Aerospace, including the full methodology, structured test results, discussion of implications, and strategic recommendations for how Collins should approach VR adoption going forward. The memorandum is available below.