Tupperware helps astronauts get fresh veggies, even in space

Tupperware Brands Corp. has received a U.S. patent for its injection molded Passive Orbital Nutrition Delivery System device designed to grow vegetables in zero gravity on the International Space Station.

The PONDS device, designed in partnership with NASA, has had three versions tested on board the ISS, David Kusuma, Tupperware's vice president of research and development, told Plastics News.

"NASA approached us a number of years ago when we were working with their technology transfer group," Kusuma said. "[PONDS] was one of several designs NASA was evaluating in order to replace what they had already on ISS.

"With space crews being in orbit longer and longer, even eclipsing a year, having access to fresh vegetables becomes really important," he said.

Astronauts usually eat freeze-dried meals that are prepared at the Johnson Space Center in Houston, Kusuma said.

Starting with the NASA-made prototype, Tupperware worked with Techshot Inc., an official spaceflight implementation partner of the ISS, to test its hardware designs.

The device needed to be "passive," he said, "meaning that it did not require any additional energy in order to make it work."

"It just uses natural forces," Kusuma added. "One of the things we had to solve was the fluid dynamics in zero gravity."

Tupperware also "leveraged" the expertise of contacts at NASA "to solve the problem," Kusuma said.

"The big challenge from an engineering point of view is how do you get water where you need it to be," he said.

Unlike on Earth, Kusuma said, "where if you pour water into a potted plant, you know everything will follow a natural order."

In space, he said, water "just wants to go everywhere."

Tupperware used "generous curved surfaces" in PONDS instead of sharp inner corners, where water "tends to want to cling," Kusuma said.

It also used its materials "to wick the water from the reservoir to the root cylinder where the plant is grown," he said.

So far, Tupperware has launched PONDS three times to the ISS for testing.

On Tupperware's first attempt, which was launched in April 2018, the PONDS units were "overwatered."

"The next point of focus was to allow less water to flow," Kusuma said. During the second mission, he said, "everything germinated but the seeds were too dry."

NASA launched Tupperware's third mission to the ISS in March 2020.

During this test, Kusuma said, the plants grown in PONDS grew stunted, or smaller than they should have been. NASA said the seeds were "overirradiated," he said, a process NASA applies to organic material to ensure no bacteria or pathogens enter the ISS.

Tupperware's third PONDS test is currently still on the ISS and expected to return to Earth at the end of November, he said.

Astronauts can now grow three types of lettuce with PONDS: Chinese cabbage, mizuna mustard and red Russian kale, Kusuma said. They have also successfully grown zinnia flowers and hope to begin growing cherry tomatoes.

"Those have always been difficult to grow in space … and that's because tomatoes use a lot of water," he added.

"Normally when NASA is working with a company to develop something for space, they don't need too many units," he said. "They're only sending one or two to the ISS … In our case, they said they already needed 100 straight away for ground tests even before they launched."

NASA's original PONDS prototype was "made out of many pieces you would find in a hardware store, like PVC pipe connected together using screw threads," Kusuma said.

Tupperware designed injection molds to meet NASA's testing need for the product and consolidated more than 30 pieces in the prototype down to just five "main" molded pieces.

"Usually, things for space are almost handmade, crafted one at a time," Kusuma said. "Now NASA can have as many of them as they need for future missions."

Tupperware was also able to use its experience with food-safe polymers in the PONDS device, making it suitable for direct food contact.

The device has a compression-molded silicone gasket, which makes PONDS watertight. It was also made compatible with existing ISS equipment like hoses to refill the water reservoir.

The fourth, and hopefully final, PONDS test will be launched some time in early 2021, Kusuma said.

"Hopefully the treatment of the seeds will be proper and they'll get good results," he said.

NASA will launch the same units as the third launch, Kusuma said. "There's no further engineering work we're asked to do in the meantime.

"If everything goes well, this PONDS [version] will be classified as approved equipment by NASA," he said. "It will have some real use onboard the ISS and hopefully also into deep space."