Flight Experiments
It would be possible to fly a piece of hardware and find out afterwards that it didn’t work, but that approach is empirical and extremely expensive, and it is not the MELiSSA way. The project favours intensive characterisation of its processes on the ground first, then competes for a flight slot through international calls such as ILSRA. That discipline means the programme is evaluated at every stage, and it has produced a strong track record: MELiSSA’s most recent flight, ARTEMISS, kept working through several weeks of launch-pad delay, started all four of its bioreactors on schedule once in orbit, adapted its protocols in flight, and returned convincing engineering results demonstrating the conversion of carbon dioxide into oxygen.
Nine experiments have now flown aboard the ISS and the Foton capsule, almost all of them selected through international competition, and their results have been published. The next flights in preparation are for plants (WAPS) and for urine (URINIS).
MESSAGE 1
ISS · 2002
MESSAGE 2
ISS · 2003
MOBILIZATION
ISS · 2004
BASE A
ISS · 2006
BASE B & C
ISS · 2008
NITRIMEL
Foton · 2014
MELONDEAU / BISTRO
ISS · 2015
ARTHROSPIRA-B
ISS · 2017–2018
ARTHROSPIRA-C / ARTEMISS
ISS · 2024 — demonstrated CO2-to-O2 conversion kinetics
WAPS (plants) and URINIS (urine) are the next experiments in preparation.
From precursor to technology demonstrator
Each precursor experiment answers a narrow scientific question in orbit; the technology demonstrators that follow turn that answer into hardware the crew can actually rely on. Four lines are currently in progress, each targeting 2030:
Batch and continuous photobioreactor cultures (2017–2023) are informing a photobioreactor for crew cabin air revitalisation, developed with Beyond Gravity.
A feasibility study on urine nitrification in space underpins a nitrifying bioreactor for crew urine treatment.
Work on microgravity effects on plant physiology feeds into a precursor Food Production Unit for controlled cultivation of edible tuberous plants.
Biorat 1 and Biorat 2 are developing the closed-loop validation model for the crew compartment itself, using a small-mammal habitat to test the loop end to end.
Bench scale to flight hardware
Getting a biological process to survive launch, vacuum and years of unattended operation is an engineering discipline in its own right. MELiSSA hardware is developed from lab breadboard models, through cleanroom qualification, to flight units integrated into ISS racks such as EDR2 — the same rigorous path every subsystem in the loop has to complete before it is trusted with a crew’s air, water or food.