Below excerpt taken from SSEP - Designing the Flight ExperimentIn terms of experimental design, the essential question is:
What physical, chemical, or biological system would I like to explore with gravity seemingly turned off for a period of time, as a means of assessing the role of gravity in that system?
And when you’re thinking about a possible experiment, you need to consider that there are constraints on your design, for instance:
- no more than 2 or 3 experiment samples (fluids and/or solids) can be brought together; you can also just fly a single sample that requires no mixing in orbit
- the experiment will be done in the shirtsleeve environment of the International Space Station
- sample volumes are small—this is a mini-lab with small ‘test tubes’
- the experiment can be ‘turned on’ by an astronaut, and proceeds on its own for a prescribed number of days in orbit; an astronaut might even ‘turn it off’
So … consider some basic examples for a possible experiment—
a. You might explore whether a seed germinates in space the way it germinates on Earth. Some of the critical questions here— Does a seedling have a sense of gravity? Does it know up from down? Is gravity important for proper germination and maturation? What will happen if you take gravity away and allow a seed to germinate? What about long duration space flights where astronauts would need to grow their own food, is it important to know if a seed germinates appropriately in space, and then goes on to grow to maturity? Are some seeds better adapted for germination in microgravity than others? Here’s a challenge: what other questions might come to mind if you brainstorm this as a class? THERE! You are doing experiment design.
b. What about food in space? Do food products in microgravity retain their nutritional value? How long will they remain consumable, i.e., is their shelf life the same as here on Earth? Do bacteria in space spoil food at the same rate as here on Earth? Might those bacteria be somehow affected by microgravity? Your turn to continue brainstorming this one too!
c. Cells are the basic functional unit of life. Their function is pretty important for long duration spaceflight both for the health of the astronauts, and the foods that would need to be grown on the spacecraft. What kinds of questions might you brainstorm regarding cell function in microgravity? Is there something you might put in a test tube bound for orbit that would help you explore answers to your questions?
d. What about the life cycles for different organisms? Is the life cycle dependent on gravity? How would the initial phases of an organism’s life and growth be impacted if we turn gravity “off”? Could that lead to an understanding of the role gravity might play in an organism’s development here on Earth?
To continue reading this article go to: SSEP - Designing the Flight Experiment
To read about SSEP experiments that have flown on previous missions follow the links on: SSEP - Experiments Selected for Flight
