Idea Implementation

A number of brainstorming sessions were organized between the Lab team and Hardware team to discuss innovative and creative designs. The Biofrag went through 2 theoretical versions and 2 physical versions. The physical characteristics were inspired by the Bioball design used within fishtanks for cleaning. That being spherical and porous. The physical designs were made via Openscad, a 3D software. Each idea that was put forth was contested with possible downfalls, ensuring that the team had answers for any problems that the mechanism may encounter. The final version saw all previously held ideas, improved upon, and thus the final version was able to facilitate the actions which we needed it to, in an optimal fashion. Furthermore, once the idea had been realised through the use of 3D printing, the team was then able to apply it to soil and determine whether the Biofrag could facilitate plant growth whilst also determining optimum growth conditions/ limits of the Biofrag.

After considering storage issues on the way to Mars and how we would make soil sampling and subsequent soil sample testing easier for the operators/scientists, the team developed what came to be known as a Biofrag Isolation Unit or BIU for short. This Isolation Unit was developed to act as a housing unit for the Biofrags(on the way to Mars) non-bioremediated soil(when stationed on Mars). This Isolation Unit will also simplify the analysis of soil samples by inserting two sensors (oxygen and chloride). These sensors were chosen as oxygen and chloride are the by-products of the bioremediation process when using chlorite dismutase and perchlorate reductase.

Practical Implementation

Due to the convenience and long storage ability, the engineered bacteria will be grown, passaged, and frozen within vials in liquid nitrogen vapour phases. These bacteria will be thawed on Mars and grown within liquid media (Davis minimal media broth) within bioreactors for use with the Biofrag for bioremediation.

Biofrags will be assembled in space (after 3D printing on Earth). Assembly involves the insertion of sponge layers (for biofilm formation and bacterial proliferation) and martian soil within the hollow core existing between both portals. The sponge will be saturated with fresh media (housing the engineered bacteria) before the Biofrag is planted into the ground. Bioremediation is allowed to commence and a seed is planted, through the portal, into the now remediated soil.

For large-scale remediation, it was planned that large holes could be excavated from the surface and then lined with coarse plastic sheeting. These formed holes could have multiple layers of biofrags inserted into them thus providing a vast area of remediation potential. Ensuring the excavations were completely lined would guarantee complete remediation. This sheeting would not only make available the chance to essentially ‘bag up’ large volumes of remediated soil, but it would also provide a biosafe barrier preventing bacterial loss and potentially uncontrolled release into the environment.

Due to the Biofrags small nature, it provides the perfect environment for initial seed growth of larger plants, and the location, once planted, allows for easy extraction and opening of the Biofrag to access the seedling within. These seedlings in turn can be transferred to deeper areas of remediated soil where they can be allowed to reach maturity. The high-quality modeling of each Biofrag means they can be used multiple times with only the bacteria needing to be reapplied to them between plantings. The light-weight and durability of the Biofrags ensures they will not only stay intact during delivery to Mars, but they can also be assembled and manipulated by one person meaning remediation projects require fewer people, something essential on the initial habitation of the planet.

It was envisaged that multiple Biofrags may be constructed incorporating varying materials. The idea was that biodegradable materials would remove the need for continuous planting and excavating used Biofrags, whilst simultaneously allowing unimpeded growth of the seed within.

Whilst large volumes of remediated earth could be transported and utilized within controlled environment ‘greenhouses’ to grow food, trees, etc, without the ability to test the effectiveness of bioremediation properties the burying of multiple Biofrags may be redundant, and as such, the need to understand perchlorate break down/bacterial efficiency was essential. Team MTU-Cork designed a novel housing system to replicate large scale horticultural areas on Mars in order to complete all testing of both the Biofrag and the engineered bacteria with them. This was named the Biofrag Isolation Unit (BIU).

The Biofrag Isolation Unit (BIU) was developed for testing and analysis of pre and post bioremediated soil samples. The simplistic yet effective design which incorporates two sensors (oxygen and chloride) will allow for ease of testing to ensure that the operators/scientists will know when bioremediation had taken place. The BIU also acts as a storage unit for the un-assembled Biofrags on their trip to Mars.