ISRO has successfully germinated black-eyed pea (lobia) seeds in space using its Compact Research Module for Orbital Plant Studies (CROPS).
On lengthy space missions to colonize celestial bodies like Mars and the Moon, space-grown plants can provide a sustainable food source. Since plants release oxygen during photosynthesis, growing them in space can help maintain breathable air aboard spacecraft.
Is it hard to grow plants in space?
The lack of gravity prevents plants' roots from growing downward, making nutrient delivery a challenging task.
Plants grown in space also need to be protected from the high levels of radiation that can damage their DNA and hinder growth. They must also be insulated from extreme temperature fluctuations — often spanning hundreds of degrees — that are common in space.
Light conditions, especially in the outer Solar System where sunlight is scarce, pose another challenge. Without light, photosynthesis stops, and plants begin to consume more oxygen than they produce.
The most common way to grow plants in space is hydroponics. Water and nutrients in hydroponically grown plants are delivered via liquid solutions rather than through soil.
Plants can also be grown aeroponically, which eliminates the need for soil or any other medium. This method reduces water usage by 98%, fertilizer usage by 60%, and eliminates the need for pesticides altogether.
Plants grown in aeroponic systems have been shown to absorb more minerals and vitamins, making them healthier and potentially more nutritious.
The ISRO CROPS box is like a mini greenhouse. It contains a soil-like medium, lobia seeds, water, sunlight-mimicking lights, and Earth-like air. “The only thing different is gravity, at around 1% of the gravitational strength on the Earth’s surface.” For photosynthesis, ISRO used four warm LEDs and four cool LEDs.
Leafy green vegetables like lettuce, spinach, and kale, which grow quickly, require little space, and are rich in nutrients, are ideal space plants.