Sowing in space: Seed film enables crew-planted crops on the International Space Station

Kurzfassung

As efforts continue toward long duration space missions, it is vital that crew members that are a part of these missions have access to whole food nutrition, dietary variety, and psychological stimulation. Space crop production research has shown that fresh vegetables could provide these properties, and, historically, this research has consisted of ground sewn seeds attached to flight hardware. The single use nature of this approach has made it apparent that crew-mediated seed sowing is necessary for sustainable food production. Scientists at NASA's Kennedy Space Center (KSC) developed a food-safe water-soluble polymer known as seed film into which seeds can be embedded for storage and planting. The reported properties of several polymers were evaluated, and a pullulan formulation was developed, tested, and selected, with the methodology refined to produce a functional approach. This technology was utilized within the Veggie hardware for the VEG-03 J technology demonstration. 'Outredgeous' red romaine lettuce seeds were embedded in the seed film on the ground before being planted by the crew aboard the International Space Station in tandem with ground-grown plants. The mature plants were harvested and returned for molecular and microbiological analyses at KSC via next generation sequencing and plate count data, respectively, for both bacteria and fungi. The data from this experiment did not indicate any negative effects from the introduction of the seed film material, while demonstrating the potential to benefit both germination time and percent viability when compared to data from previous Veggie experiments. The technology itself is flexible in application and merits further study of its capabilities for implementation in a space crop production system.