Maleth I, II & III: Malta’s journey from the clinic to orbit

Some journeys into space begin with a problem on Earth. For Project Maleth, that problem was the diabetic foot ulcer: a wound in which human tissue, microbial communities and a patient's health meet. The ambition was to take a clinically important question from Malta into orbit, then bring the samples and the evidence home.

Across Maleth I, II and III, that ambition became a research programme. Each mission added something: the first established the route, the second pursued replication, and the third widened the collaboration. Together, they tell a story about what a small country can contribute when scientific purpose meets international partnership.

Sunrise from the International Space Station, 29 September 2023. Credit: NASA / ISS Expedition 70, ISS070-E-1178; image courtesy of NASA Earth Observatory. This contextual image shows the orbital environment, rather than a Maleth payload.

Maleth I · 2021: taking the question into orbit

Malta's first space bioscience mission carried human tissue samples from diabetic foot ulcers, together with their associated microorganisms, to the International Space Station. The University of Malta's launch coverage records the SpaceX CRS-23 launch campaign in August 2021.

The experimental logic mattered as much as the destination. Portions of the tissue were allocated to different analyses, with samples travelling to the ISS and comparison samples remaining on Earth. This made a spaceflight–ground comparison possible, while retaining a connection to the clinical material that motivated the work.

The first peer-reviewed account, Gatt and colleagues in Heliyon, used 16S rRNA gene sequencing to examine bacterial communities. It reported differences among sample types and a heterogeneous microbiome in the returned ISS samples, including distinctive abundance patterns for particular bacteria. The paper also documented limitations: six flight biological replicates, and a delay before the returned tissue was processed in Malta.

Those details define what the study can support. It describes microbial communities under the conditions of this experiment; it does not establish a new wound treatment or isolate microgravity from every other feature of spaceflight and sample handling. Its sequencing data are available through NASA's Open Science Data Repository, OSD-487, allowing others to examine the evidence.

Maleth II · 2022: making repetition part of the journey

A first mission creates possibilities. A second asks whether the scientific approach can travel again and produce evidence that can be compared.

Maleth II launched on SpaceX CRS-25 in July 2022, again using the ICE Cubes service on the ISS. The programme explicitly aimed to replicate and validate aspects of Maleth I.

The mission preparation account also describes a yeast experiment alongside the tissue and microbiome work. Behind the flight were practical steps that rarely appear in a launch photograph: assembling the payload in Belgium, coordinating transport and integration, and establishing remote monitoring from Malta.

Replication is part of the excitement. When another mission is designed around an earlier question, a memorable demonstration starts becoming a programme that can accumulate evidence.

Maleth III · 2023: a wider scientific partnership

For the third mission, the collaboration became more international. ESA's Maleth III account described the experiment prepared for SpaceX CRS-27 in March 2023: diabetic foot ulcer samples from three patients at King Faisal Specialist Hospital and Research Centre in Jeddah, alongside three normal control samples from Malta.

The announced analysis plan extended towards human and microbial genome sequencing, with collaborators including Weill Cornell Medicine. These were stated research objectives; the mission announcement itself is not a report of completed genomic findings.

The same account highlights Christine Gatt's doctoral work and the network connecting the University of Malta, RIDT, Space Applications Services, Spaceomix and international partners. A later University of Malta report records the three missions as completed journeys to the ISS and back between 2021 and 2023.

What the trilogy makes possible

The RIDT overview of the Maleth trilogy places these missions within a longer effort to connect space biology with medicine on Earth. For our group, that connection also reaches into blood research: how cells respond to an unusual environment, how we measure their responses, and which changes remain convincing when the data are examined closely.

The most lasting result of a mission may be the capability it leaves behind: trained researchers, samples with a documented history, reusable data and collaborators ready to ask the next question. Maleth's story belongs to the patients, students, clinicians, engineers, supporters and scientists who made that chain possible.

From a wound in a clinic to a laboratory in orbit, the distance is extraordinary. The scientific responsibility remains familiar: preserve the comparison, understand the limitations, and make the evidence available.

Explore the group's continuing work in blood regulation and space biology in the Globin Switch Atlas.