Our Project

The Problem

Governments and private enterprises alike are gearing up for travel across the Solar System. Plans to colonize nearby planets are underway, with Elon Musk spearheading the initiative to put a human colony on Mars by 2030. In a parallel vein, NASA is planning a manned exploratory mission to Mars as soon as the 2030s. Several other space agencies have similar plans and timelines for their own respective Mars explorations. This exciting time in our history nonetheless comes with the challenges of long-term space travel.

Two ecological and economical challenges arise: the sustainable management of waste produced in space and the high cost of shipping materials to space.

Waste management on a Mars mission will be paramount for the following reasons:

1. the need to recover as much water and oxygen as possible to sustain life in outer space,
2. the need to treat human waste to minimize health risks for the crew of a Mars mission, and
3. the need to preserve the Martian environment as much as possible.

Currently, the cost of shipping materials up to space is …. This cost will limit early Mars mission crews in the supplies that they can bring from Earth to Mars. One way to mitigate this challenge is to develop a system to produce necessary items in space as needs arise.

Our Solution

(Atika's animation goes here)

Our team is working on developing a process for bioplastic production on Mars from human waste feedstock using genetically engineered bacteria. With this project, we aim to address both of the above major challenges for future manned Mars missions.

Poly(3-hydroxybutyrate) (PHB), a bioplastic, is produced in nature by many bacterial species. Literature has shown that PHB can be produced using a variety of feedstocks, including glucose and volatile fatty acids (VFAs). Since human waste contains VFAs, it is a potential feedstock for PHB production.

Our team engineered E. coli to express some PHB-producing genes, which we optimized to make the PHB production process more efficient. We also modified the system that E. coli use to secrete unwanted molecules so that our recombinant E. coli would secrete the PHB they produce. This allows for a continuous process (as opposed to a batch process, which is less user-friendly and would require more maintenance from early Mars mission crews). Thus, when employed together, these genetic modifications create a relatively safe means of bioplastic production.

Our team also developed a start-to-finish process for our waste management and simultaneous PHB production. In the first step of this process, solid human waste is collected and fermented with naturally occurring bacteria to increase the concentration of VFAs. As a part of this process, the solids from the waste settle and the liquid rises to the surface of the fermentation tank. Next, the liquid in the fermentation tank, which contains VFAs, is separated from the solid particles, sterilized, and passed to a bioreactor inoculated with our engineered E. coli. Once the E. coli secrete PHB particles, the PHB can be continuously collected and extracted from the liquid stream. The resulting liquid can be recycled into drinking water, while PHB particles can be used in a Selective Laser Sintering (SLS) 3-D printer to generate items useful to astronauts.