Baseline Environmental Testing of Candidate Salad Crops with Horticultural Approaches and Constraints Typical of Spaceflight

The first spaceflight opportunities for Advanced Life Support (ALS) Project testing with plants will likely occur with missions on vehicles in Low Earth Orbit, such as the International Space Station (ISS). In these settings, plant production systems would likely be small chambers with limited electrical power. Such systems are adequate for salad-type crops that provide moderate quantities of fresh, flavorful foods to supplement the crew diet. Successful operation of salad crop systems in the space environment requires extensive ground-based testing with horticultural methodologies that meet expected mission constraints. At Kennedy Space Center, cultivars of radish, onion, and lettuce are being compared for performance under these “flight-like” conditions. This paper describes experimental protocols which are currently being implemented to collect response parameters to environmental conditions (i.e, expected temperature, CO₂, and light levels) that might be encountered with plant chambers that are open to the ISS cabin environment. These experiments also include intercropping or “mixed cropping” tests with multiple species in a common root tray. The results of these tests will be used to assess future salad crop growing technology in a spaceflight setting.