During the SporeSat experiment the gravitational responses of the fern spores to varying levels of gravity will be monitored by measuring the activity of their calcium ion channels. On Earth, this calcium ion current flows in the direction opposite Earth’s gravity-in through the bottom and out through the top of each spore-biochemically distinguishing up from down. One of the earliest measurable gravity-directed events is a movement of calcium ions through the germinating spores. richardii spores sense and respond to gravity within hours after germination starts. Researchers are studying spores in space to gain a more detailed understanding of molecular and biophysical mechanisms for gravity sensing.Ĭ. The plants used in the experiment are single-celled spores of the aquatic fern Ceratopteris richardii. SporeSat is an autonomous, free-flying spacecraft that will be used to conduct a scientific experiment to investigate how germinating plant cells sense and respond to gravity.
