ISS Astronauts Cultivated Chilli Peppers in Space Station's Microgravity

A field cultivar of a Hatch Chile pepper from New Mexico was sent to the International Space Station, by NASA’s Kennedy Space Center (Florida). The peppers were dwarfed inside the plant habitat. Now, after 137 days, which is the longest plant experiment in the history of the space station, astronauts are growing chili peppers in space, which is a big step for space endeavors. 

Recently, NASA’s website posted a picture of its astronaut and Expedition 66 Flight Engineer Raja Chari holding a taco made with freshly harvested peppers grown at the International Space Station as a part of the Plant Habitat-04 (PH-04) experiment. According to NASA’s reports, “PH-04 concluded as the longest – and perhaps the spiciest – plant experiment in the history of the International Space Station.” 

On 1^st December 2021, NASA’s Kennedy Space Center Twitter account tweeted “Hot Pepper these peppers are breaking records! The longest plant experiment in the history of the @Space_Station ended recently, 137days after it began. Learn more about the peppers harvested from Plant Habitat-04 & how they added some spice to the orbiting lab.” 

“The longest – and perhaps the spiciest – plant experiment in the history of the International Space Station, Plant Habitat-04 (PH-04), concluded recently, 137 days after it began. On Nov. 26, Expedition 66 Flight Engineer Mark Vande Hei harvested and with other members of the crew sampled some of the 26 Chile peppers grown from four plants in the orbiting laboratory’s Advanced Plant Habitat (APH), with PH-04 also breaking the record for feeding the most astronauts from a crop grown in space” – said NASA.

Astronaut Mark T Vande Hei posted: @Astro_Sabot – “Last week we harvested these Hatch Chile peppers and mmm mm they are good. (Next time I’m definitely going to be better about keeping my hands from my face after cutting them up though!).” 

In June, 48 sanitized pepper seeds were launched to the space station in a science carrier. On July 12^th, the carriers were inserted into the facility and added water by NASA astronaut Shane Kimbrough, initiating the PH-04 experiment. During the experiment, the astronauts performed hands-on work, which included the removal of all but four of the germinated plants, which gave each plant enough room to grow, in a total area which is of the size of a large microwave oven. 

Not all peppers, which are harvested from the experiment, were eaten by the astronauts on taco night, as twelve peppers out of them will return to Earth for analysis. 

How they cultivated peppers in microgravity onboard ISS:  

The conditions inside the APH were monitored and controlled by the team at Kennedy Space Center. Within weeks, the plants were flowering. The habitat’s fans were run at different speeds, by the team, to disperse pollen, and some hand pollination was performed by the astronauts.  These efforts soon led to fruit, as on 29^th October, the first crop of seven peppers was picked by Vande Hei.

The first harvest was eaten by the crew, with NASA astronaut and Expedition 65 flight engineer Megan McArthur who added the peppers to a taco made using fajita beef, rehydrated tomatoes, and artichokes. “The level of excitement around the first harvest and the space tacos was unprecedented for us” – said Romeyn, and added, “All indications are some of the fruit on the spicier side, which is not expected, given the unknown effect microgravity could have been on the capsaicin levels of peppers.”