Source: AgAnswers, an Ohio State Extension and Purdue Extension Partnership

The National Aeronautics and Space Administration (NASA) considers farming a matter of survival for future long-term space missions. Plants provide food when deliveries from Earth aren't feasible and make air breathable and water drinkable. But who will care for and harvest crops when astronauts are so busy carrying out key mission tasks?

"Labor requirements to grow and harvest the crops must be reduced through automation," said Peter Ling, an Ohio State University Extension specialist and a researcher with the Department of Food, Agricultural, and Biological Engineering (FABE) on the Ohio Agricultural Research and Development Center's (OARDC) Wooster, Ohio, campus.

Through a NASA grant, Ling has led the effort to develop a robotic tomato harvester for the J.F. Kennedy Space Center. The robot is able to locate and pick ripe tomatoes -- one of the most delicate fruits to harvest.

"Growing a salad crop, having something live in a space station, is very important for both nutritional and psychological reasons," Ling said. "At the same time, automation is needed to save production and harvesting time."

The harvester includes a sensing unit and a robotic hand integrated with a commercial robotic manipulator provided by Motoman Inc., West Carrollton, Ohio.

The sensing unit, or robotic eye, scans the tomato plant and determines the number and position of red fruits. With this information, the four-finger prosthetic hand moves in the direction of the fruit. The fingers then open around the tomato and get a hold of it before a pulling, bending or torsion movement is applied to detach it.

Ling and his team -- FABE scientists Reza Ehsani and K.C. Ting, design engineer Mike Klingman, graduate students Nagarajan Ramalingam and Yu-Tseh Chi, and Mettler-Toledo International designer Craig Draper -- developed image-processing algorithms to determine sizes and locations of mature tomatoes, including ones that are partially obstructed by leaves or branches. They also improved a previously designed robotic hand, which resulted in a 50 percent weight reduction.

The harvester has been tested in the laboratory and in commercial greenhouses in Ohio. Ling said success rates of fruit sensing and picking were more than 95 percent and 85 percent, respectively. The robot was demonstrated last March at the Kennedy Space Center.

But the services of this space farmer are not restricted to future human presence on Mars or the Moon. Ling said there's interest to further develop this technology for use here on Earth.

"We are looking into developing some kind of automation to harvest not only tomatoes, but also apples and oranges," Ling explained. "This technology can be advantageous, especially for the fresh market, where you need to pick fruit one by one to get a mature, high-quality product."

Arizona greenhouse tomato growers have expressed interest in the robotic harvester, Ling said. This technology also has caught the attention of the citrus industry in Florida.

OARDC and OSU Extension are part of Ohio State's College of Food, Agricultural, and Environmental Sciences.