NOTE: This is a sub-page of the About SSEP main page which you should read first.
Experiment Opportunity
Student teams at the middle school, high school, or community college level can propose experiments designed to assess the impact of 10-14 days of microgravity (weightlessness) on a physical, chemical, or biological system. Experiments in a variety of disciplines are possible, including: seed germination, crystal growth, physiology of microorganisms and life cycles (e.g. bacteria), cell biology and growth, food studies, and studies of micro-aquatic life (e.g., Planaria Worms).
Each experiment must be designed to work within an existing, flight-ready, easy-to-use, professional research mini-laboratory, which is specifically designed to combine separate sample materials once in orbit. Each experiment loaded into the mini-lab consists of one to three samples (fluids and/or solids, e.g., seeds and a 2% sugar solution) that are located in what are effectively small test tubes. The experiment is begun in orbit when an astronaut operating the mini-lab brings the test tubes together, mixing the samples.
The samples (fluids and/or solids) used in the student experiments must be safe, and pass a real NASA Flight Safety Review.
General Framing of the Experiment—A Simple Concept
The way to think about this REAL flight experiment opportunity is pretty simple, and definitely appropriate for even middle school students—if teachers help them put on their thinking caps. It is worth noting that 9 of the 16 experiments chosen to fly on STS-134, the final flight of Shuttle Endeavour, were from middle school student teams. See the descriptions of the Selected Experiments on STS-134 at the SSEP Community Network Hubsite.
We normally observe the characteristics and processes of physical, chemical, and biological systems under the action of gravity on or near the surface of Earth. These systems all experience the “force of gravity” which dictates a number of fundamental phenomena, e.g., that objects and materials weigh something, a sense of up versus down, and that lower density materials will float on higher density materials. These phenomena are intricately connected with how systems behave, and in biological systems, are fundamental to their function (e.g., bone strength requires bone compression under the force of gravity—without it, as in orbit, bone mass is excreted, because it is no longer needed.)
But objects placed in orbit experience “microgravity” often incorrectly referred to as weightlessness, where the action of gravity magically appears to be turned off. The reason gravity seem to be absent is not immediately obvious, but it’s because an object in orbit is in a state of continuous free fall—it is a falling object. (Hmmm … what would the bathroom scale you are standing on show if you were in an elevator whose cable had been cut and is free-falling in a very very tall shaft?) NCESSE’s Center Director, Jeff Goldstein wrote an enjoyable essay on this titled, You Want Me to Do What with a Bathroom Scale? at Blog on the Universe, which teachers and students can read together.
In terms of experimental design, the essential question is:
What phenomenon associated with a physical, chemical, or biological system would I like to explore with gravity turned off for 10-14 days?
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 sample materials 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 Shuttle crew cabin or the International Space Station
• sample volumes are small—this is a mini-lab with very small test tubes
• the experiment is ‘turned on’ by an astronaut, and proceeds on its own for many days in orbit
• fluids and/or solid materials used must be safe (non-toxic)—the mini-lab is placed in the crew’s living space
So … let’s consider some basic examples of a possible experiment—
a. You might explore whether a seed germinates in space the way it germinates on Earth. The critical question here—does a seedling know up from down, in other words, have a sense of gravity? Think about how seeds germinate here on Earth. And on a long duration space flight, 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 as needed? Are some seeds better adapted for germination in microgravity than others? Hey, 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 foods that would need to be grown on the spacecraft—and for the health of the astronauts. 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?
Ok, you’re likely getting the hang of this. This is science. It’s challenging. It’s emotionally rewarding to come up with a brave new idea—a new hypothesis—to test. It’s a journey of exploration … owned by you.
At the most fundamental level, Science is really just organized curiosity. To do it, you need to reconnect with that spirit of curiosity that lives within you. And we’re giving you the chance to put forward a hypothesis and propose an experimental test of that hypothesis … aboard the Space Shuttle and International Space Station!
The examples above are just a handful of what grow naturally from a careful classroom exploration of the SSEP Microgravity Science Background and Microgravity Experiment Case Studies documents, which are meant to provide a primer on the categories of science that might be undertaken in microgravity and why, and to provide inspiration and guidance for what kinds of experiments might be proposed. It’s a great starting point for teachers to get kids thinking about experiment possibilities.
The documents address 9 basic categories of microgravity science: Bacteria, Cell Biology, Fish and Other Aquatic Life, Fluid Diffusion, Food Products, Inorganic Crystal Growth, Microencapsulation, Protein Crystal Growth, and Seed & Plant Studies. For each category these documents provide the science background, why research in this category is important, why gravity is thought to play a role, why experiments with gravity ‘turned-off’ have been done, and the kinds of experiments that might be performed in the mini-lab. It’s also important to point out that the fluids and/or solids that students use for their experiments must be selected from the Master List of Experiment Samples, which is an extensive list of non-toxic samples by category above, and which have a very high probability of passing a NASA Flight Safety Review (the majority of samples on the list have passed prior safety reviews.) After all, the goal is to fly the winning experiments is space. These documents are downloadable as PDFs from the Document Library.
Rocket Science, Scientists, Engineers, and … You
It’s not rocket science, well … it actually is:) Which means that rocket science, when boiled down to the basics, is not that hard to wrap your head around and can be a great deal of fun. (It’s what scientists and engineers get paid to do.)
You might want to read something cool about scientists and engineers as heroes. And here is a story about a team of scientists and engineers getting ready to put a spacecraft in orbit around the planet Mercury for the first time in history.
Next Steps
Now that you’ve gotten a sense of the flight experiment opportunity and the basic philosophy of SSEP experiment design, here are some next steps—
If you arrived on this page from the About SSEP main page, and you’re exploring whether your community would be interested in participating in SSEP, you may want to go back to the About SSEP main page, and continue reading.
If your community is already participating in SSEP, and you’re here to gain basic insight into SSEP experiment design philosophy, then other pages of interest include:
The Current Flight Opportunities main page, where you will find an overview of the flight opportunity in which your community is engaged, and whose sub-pages include your flight’s Critical Timeline with important milestone events and deadlines, and your flight’s Mini-Laboratory Operation. You need to understand how your assigned mini-lab works, its specifications, and the constraints it imposes on your experimental design so you can start noodling around an experiment that your team can propose to fly. Here’s your chance to be a scientist right now. (REALLY)
The Teacher and Student Proposer Resources main page, which provides an overview of all the resources we’ve made available to you, including the Documents Library and FAQ, and—for teachers—the extremely helpful resource titled: To Teachers—How to Move Forward, which provides a straightforward, easy-to-follow recipe for getting your class moving on SSEP and Experiment Design.