Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.

The ISS crew has grown mixed greens and is now running two Veggie facilities simultaneously. (NASA)

The goal of NASA's Veggie team is a fresh and tasty salad on Mars. While other NASA programs are working on getting to the Red Planet, the Veggie team is figuring out how to grow salad ingredients in space, with an interim goal of a salad on the International Space Station (ISS). The Veggie program is named for modular growing units designed by Orbital Technologies, and is a type of astronaut garden. To grow red romaine lettuce on the ISS, NASA scientists teamed up with Sarasota, FL-based Florikan, a company that had already been working with NASA to develop polymer-coated, controlled-release fertilizer systems.

For NASA's hydroponic growing system in space, the injectable liquid fertilizer that's typically used in hydroponic systems could not be used because water floats in microgravity, and those systems typically require multiple applications, which isn't practical for astronauts. Single-application nutrients had to be provided without mixing them in water.

The team developed a way to incorporate Florikan controlled-release fertilizer into the baked ceramic that holds the roots of NASA's Veggie plants instead of normal soil. The fertilizer released itself over the life of the plants so the astronauts didn't have to tinker with it. By August 2015, astronauts were eating red romaine lettuce grown in the ISS, but a real salad needs more than just lettuce. Flowering vegetables like tomatoes and peppers are the true keys to excellent salads. Although NASA has been testing a Chinese cabbage in the interim, the next plan is to grow dwarf tomatoes.

The fertilizer adapted for NASA's lettuce crop was Nutricote 18-6-8 formula, named for its ratio of nitrogen, phosphate, and potassium. Florikan has been selling Nutricote for decades, but when contacted about growing tomatoes and peppers, Florikan determined that the 18-6-8 ratio was not the right formulation for flowering plants. On Earth, farmers might just grow tomatoes and peppers with the 18-6-8 formula and manually add extra potassium, but NASA aimed to make the process as hands-off as possible.

Red Robin tomatoes, growing in vertical hydroponics at Sweetgrass Farms, use the fertilizer formula developed by Florikan for use in space.

Florikan came up with a new formula specifically designed for hydroponically grown flowering plants. The product was similar to the fertilizer that successfully grew red romaine on the ISS, so it was mostly space-tested. It used the same polymer coating, the same release characteristics, and the same nutrients, with the nitrogen reduced and the potassium increased. The result was a 14-4-14 NPK formulation — 14 parts nitrogen, 4 parts phosphate, and 14 parts potassium.

With the guidance of Kennedy Space Center researchers, Florikan began developing fertilizer with the “NASAgrade” polymer coating the company still uses today. An early version of this fertilizer didn't hold up in heavy rain, which wasn't a consideration for space. For earthbound farmers, the company came up with a polyurethane wax undercoat that successfully resolved the issue. The 14-4-14 formula that was already being used in NASA experiments and commercial hydroponics on Earth is the first controlled-release fertilizer to work successfully in vertical hydroponic farming, replacing liquid feed and the need for multiple applications.

Among the earliest commercial adaptors of the 14-4-14 formula was Sarasota, FL-based Sweetgrass Farm, a fully hydroponic operation that in 2016 began the process of converting to exclusive use of Florikan's fertilizer system. The plants grown with the fertilizer were healthy, vibrant, productive, and of exceptional quality.

Florikan worked with Sweetgrass Farm to test seed-to-seedling yields using a nano-sized version of the 14-4-14 formula, which involves much smaller granules. NASA also started testing the nano-formula, which makes it possible to achieve nearly perfectly even fertilizer distribution.

Such applications have environmental benefits as well. Farmers don't have to buy as much fertilizer because less of it gets lost in runoff that contaminates rivers, streams, and entire watersheds. Florikan has been recognized by the U.S. Environmental Protection Agency (EPA) for its success in reducing excess fertilizing nutrients.

Visit here 


Tech Briefs Magazine

This article first appeared in the August, 2018 issue of Tech Briefs Magazine.

Read more articles from this issue here.

Read more articles from the archives here.