Hi Carly,
If I went on a space mission, I think I would try growing orchids in space. There would be a lot of unique challenges involved, since some orchids have very specific light and temperature requirements. I would also need special equipment to grow the plants, since growing them in regular flower pots with the usual soil/pine bark mixture or sphagnum moss probably would not work very well in a microgravity environment.
However, many orchids are epiphytes, which means they do not normally grow in soil. Instead, they use their roots to anchor themselves to the trunk of a tree. Even though they naturally attach to trees, these plants are not parasites - they get their nutrients from rainwater. They way most orchids are grown in greenhouses (stuffed into flower pots filled with a pine bark potting mix) is therefore NOT the way they would grow in the wild. People have been experimenting ways of growing orchids that don't need soil, such as growning them in hydroponic or semi-hydroponic media. A lot of orchids do quite well when grown this way. I pasted a photo below from the Eastern Iowa Orchid Society's most recent newsletter showing me with some of my dendrobium orchids. These plants are being grown in a semi-hydroponic medium - basically porous ceramic pellets that hold water. The pellets look like dog food on the outside, but when you break them open, they look a bit like black pumice on the inside. The drainage holes in the plastic pots in the photo are on the side instead of the bottom like on a normal flower pot. This creates a reservoir of water in the bottom of the pot so that the water can wick up through the ceramic pellets to keep the plants moist.
It just so happens that astronauts on the International Space Station have been experimenting with growing plants hydroponically in a microgravity environment. You can read more about these experiments here:
http://spaceflight.nasa.g...acechronicles13.html
http://science.nasa.gov/h...y2001/ast09apr_1.htm
Growing plants in space can help provide food on long space missions and help keep the air breathable and water drinkable on board the spacecraft. Growing orchids wouldn't help with food, but maybe they could help with air and water purification. Plus, the pretty flowers would help brighten up the space capsule!
Kris