The Veg-01 hardware validation test investigation utilizes the Veggie facility on ISS. This investigation will assess on-orbit function and performance of the Veggie, and focus on the growth and development of ‘Outredgeous’ Lettuce (Lactuca sativa ) seedlings in the spaceflight environment and the effects of the spaceflight environment on composition of microbial flora on the Veggie-grown plants and the Veggie facility. Lettuce plants are harvested on-orbit, frozen at <-80oC and returned to the ground for post-flight evaluation. Microbial sampling swabs will be taken of the Veggie facility and plant material, frozen and returned to the ground for environmental microbiological examination. Rooting pillows and water sample syringes will also be returned for microbial sampling and root analysis.
The primary goal of the Veg-01 testing will be to demonstrate plant growth in the Veggie hardware using lettuce as a test species. Plants will be grown in two different sizes of arcillite, a calcined clay media. This test will help us compare root zones of the two media sizes to determine water and root distribution in the different sized-particles to provide recommendations for future Veggie investigations. Shoot samples will also provide information on any growth anomalies when compared with ground controls and will provide information on microbial growth and food safety. Photographs will be used to assess plant growth rates and plant health. A data logger will record the environment within the Veggie hardware. Crew questionnaires will provide insight into the appropriateness and thoroughness of the crew procedures for Veggie hardware and plant growth operations.
Pillows are single use and thus reduce the chances of microbial contamination of the Veggie hardware and produce. A major aspect of the proof of concept flight, Veg-01, is to collect baseline microbial data from plants and pillows grown on ISS. Ground testing has demonstrated very low microbial levels on lettuce plants grown in Veggie-relevant conditions. Discussions with space microbiologists, flight surgeons, and space food technologists at JSC indicate that if microbial levels are sufficiently low the crew could consume the fresh produce without sanitizing. For crops that naturally have higher levels of microorganisms (e.g. radishes, which grow in contact with water and nutrients) a space-rated produce sanitation method must be developed and tested.
The baseline data collected from the Veg-01 flight will be a resource for future Veggie investigations. This information will provide data on necessary procedural changes, hardware upgrades or horticultural options as Veggie becomes an integral part of ISS expeditions in the future.
Veggie is considered one of the most advanced salad-machine precursors available, and has recently passed the Phase II NASA flight safety review as the hardware is developed for flight to the ISS.
Nutritional and horticultural evaluation results are being analyzed. Microbiome sequencing data will be made available through the GeneLab Data System.