How to Send Your Experiment into Space: Anatomy of a Space Experiment
Scientists studying the effects of gravity face the difficulty of designing experiments that isolate the effects of gravity. Ideally, this means conducting an experiment in the absence of gravity – no easy task while on Earth. Certainly, the best place to run a long-term gravity experiment is space or while orbiting the Earth in microgravity conditions; however, getting your experiment into space might be as hard as neutralizing gravity on Earth. This is the dilemma Dr. Sarah Wyatt faced in the search for the genes controlling the signaling pathways of plants responding to changes in gravity.
When NASA Research sent out a call for research proposals for the International Space Station (ISS), Wyatt recognized an opportunity for the Wyatt Lab to take their gravitropism research to the next level. Perhaps you have an experiment you want to run aboard the ISS? Or maybe you just want to know what it takes to get on the ISS research roster. The following briefly describes some of the major milestones in designing and deploying an experiment in space.
Figure 1: NASA BRIC-20 Major Project Milestones
Step 1: Land a NASA Research Grant. The window of opportunity opens when NASA Research announces a request for proposals (RFP) soliciting research that will help them progress toward their long-term space mission goals. If your research aligns with NASA’s needs then you put on your grant-writing cap and start typing. A few months later the RFP deadline passes and the proposals are peer reviewed by a committee of scientists appointed by NASA who select which projects will fly. The top proposals are then sent to a technical review board to assess the feasibility of transporting and then performing the experiment aboard the ISS. After clearing these hurdles, the scientists whose projects are selected receive notification of funding and the project is scheduled. At this point, the principle investigators (PIs), in this case Dr. Sarah Wyatt and Dr. Darren Luesse, are assigned a NASA project support engineer and the long, hard work of figuring out how the research team and NASA will coordinate their activities to operationalize the experiment begins.
Step 2: Definition. During this phase researchers define the protocols, parameters, and tolerances surrounding the space experiment. There are a lot of things out of a scientist’s control when staging a test in space – especially when working with time-sensitive events like seed germination. Foremost, a scientists must be certain that their experiment can travel to space before being activated. This means that from the minute the experiment is packaged and loaded into the cargo hold of the SpaceX Dragon capsule until the minute it is activated by the researchers aboard the ISS, the experiment must be suspended. Planning requires the research team account for contingencies such as launch delays or events in orbit that might delay docking to the ISS. Defining the amount of time (and other key variables) that the experiment can withstand before impacting results is the primary goal of the definition stage.
Other important considerations that must be addressed at this stage are any remaining technical concerns in the preparation or analysis of the experiment. In the Wyatt Lab, graduate student researchers Proma Basu and Marilyn Hayden both defined and tested protocols surrounding protein and mRNA extraction and storage of the Arabidopsis seedlings. Since there has been little research focused on plant proteins in microgravity environments thus far, the researchers had to define and verify protocols for proteome extraction and analysis in space-flown experiments without the benefit of a solid precedent.
Step 3: Science Verification Testing (SVT). Once the principle investigators and their NASA counterparts are convinced that the research team has sufficiently tested the experimental protocols in relation to the variables introduced by space flight, it’s time to test the science. At this point the principle investigators travel to the Space Life Sciences Laboratory (SLSL) at the Kennedy Space Center (KSC) in Cape Canaveral, Florida to run through their experimental protocols using actual NASA hardware. For our experiment this requires plating specimens in plates (petri dishes) and then mounting the plates in a petri dish fixation unit (PDFU), and then loading the PDFUs into biological research in canisters (BRIC) containers that will house the experiment for the duration of the flight. The team may run through certain aspects of the experiment to ensure it is well integrated with the NASA hardware. Then the research team return to their labs to fine-tune their protocols for the BRIC environment.
Step 4: Payload Verification Testing (PVT). At this point, the principle investigators again return to the Space Life Sciences Laboratory (SLSL) at the Kennedy Space Center (KSC) for a complete dress rehearsal of the experiment. From KSC the researchers will run the experiment exactly as they expect it to be run on the ISS. At the end of the PVT, the experiment is de-coupled from the BRIC containers and the researchers fly back with their treatment and controls samples to their research facilities to analyze the results. The next time they fly to KSC, it will be the real thing.
Step 5: Launch your experiment into space, activate it aboard the ISS, and return it safely to Earth for analysis. Before launch day, the experiment is again plated, loaded into PDFUs, and loaded to BRICs, but this time it is then loaded into the cargo hold of the SpaceX Falcon 9 spacecraft and secured for lift off. After achieving orbit, the SpaceX Dragon capsule detaches from the Falcon 9 booster stage and continues on to rendezvous with the ISS. Once the Dragon is docked and unloaded, the researchers aboard the ISS unpack the experiment and according to a well-scripted NASA protocol, activate the experiment. The seedlings are warmed to room temperature and within 24 hours the seedlings begin germinating. On the ground, an exact copy of the experiment is run in parallel to serve as a control. The control lags the space experiment by ~24 hours to allow information sent by the data loggers recording the micro climates inside the ISS BRICs to be downloaded to KSC and used to reproduce the exact same temperature and humidity conditions in the control BRICs. Then after 72 hours, an ISS researcher will stop the experiment using a fixative – instantly halting and effectively freezing the experiment. The BRICs are then prepared to return to Earth with the Dragon capsule.
Step 6: De-integrate the experiment from the BRIC and fly it back to the lab for analysis. Once the Dragon is recovered in the Pacific Ocean, the contents will be unpacked and the experiment de-integrated from the BRICs and the fixed seedlings flown back to the Wyatt Lab at Ohio University where Basu and Hayden will extract proteins and mRNA and then submit the samples to detailed analysis. By comparing results between space-flown and ground-grown seedling tissue, Dr. Wyatt and Dr. Luesse hope to complete a model of the signaling pathways plants use when responding to changes in gravity. This completed map (a detailed computer model) will help scientists and NASA engineers determine how to optimize plant life on space craft to accompany astronauts on long-term space deployments.