Microbes, spacecraft, and cheerleaders: The ISS payload story of Project MERCCURIby Bart D. Leahy
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| Not everyone who develops an ISS science experiment was born with a burning desire to do work in space. |
Say you’re an aspiring postdoc, space-minded entrepreneur, or citizen scientist, and you want to get your hardware up to the microgravity environment of the United States’ orbiting National Laboratory. How do you go about it? How do you get funding? How do you get the public interested and involved in what you’re doing? This brief history of Project MERCCURI will attempt to answer some of those questions.
The beginning
Not everyone who develops an ISS science experiment was born with a burning desire to do work in space. Project MERCCURI’s investigators are primarily microbiologists, whose work concerns life on Earth since that’s where we all live. However, moving research into space can do several things for a project:
- Help researchers control for variables outside the typical Earth environment (e.g., gravity).
- Improve the chances for getting funding—especially from NASA or other space-related organizations that have an interest doing work beyond Earth.
- Add a public relations/outreach component to an experiment that otherwise would be of interest only to other scientists.
In the case of our project (I was responsible for coordinating sample collection for Project MERCCURI), a competition gave impetus to pursuing a research topic that incorporated citizen science. In 2012, Space Florida and NanoRacks, LLC, co-sponsored and established the Space Florida International Space Station (ISS) Research Competition, the winners of which would get to conduct scientific research on ISS, with Space Florida covering the costs of transporting the research payload to the station. The competition fast-tracked an idea being developed by a team comprising Jonathan Eisen, a microbiologist from University of California (UC) Davis; Mark Severance, a NASA communications manager; and Darlene Cavalier, founder of the citizen-science site SciStarter and the Science Cheerleaders, to propose an activity that would combine microbiology research with citizen science, space research, and a lot of public relations flair. The resulting proposal, which was one of the winners of the competition, is known as Project MERCCURI (Microbe Ecology Research Combining Citizen and University Researchers on ISS).
Project MERCCURI includes several components:
- Collecting microbes nationwide for the Earth Microbiome Project, which is mapping the presence and prevalence of microbes worldwide. Four thousand samples were collected from cell phones and sneakers, primarily by teams of Pop Warner cheerleaders and the Science Cheerleaders. (My job was organizing these sampling events and cheerleader appearances as well as making sure that each group received the correct number of microbe-swabbing kits).
- Comparing the growth of microbes from built environments on Earth with their growth on ISS. 48 microbe samples launched to ISS on SpaceX’s Commercial Resupply Services #3 (CRS-3) mission to be studied in the ISS lab. This activity will have a public outreach component, too, as microbes from NFL stadiums—including Levi’s Stadium, new home of the San Francisco 49ers, and Gillette Stadium, home of the New England Patriots—as well as public landmarks like the Liberty Bell and the Freedom 7 Mercury spacecraft flown by John Glenn, will be evaluated in “playoffs” to determine which ones grow the fastest and compared to the fastest-growing microbes on Earth.
- Comparing the types of microbes found on Earth with microbes found by astronauts swabbing high-traffic areas of the ISS. This part of the project has a space exploration-related benefit, as the presence of pathogenic and beneficial microbes will impact crew health on long-term space missions. The public outreach portion of this part of the project includes a website, which is posting pictures of and information about microbes found by the sampling teams on Earth as well as microbes found on the Station.
The whole experiment will be in space from launch until the scheduled May 18 unberthing and return of the Dragon spacecraft. Once the ISS astronauts have collected their samples and evaluated the samples from Earth, they will pack them back inside Dragon’s experiment storage section, which will be recovered from the Pacific after its return to Earth. During the samples’ time on the station, the Earth microbes will have their growth rate measured while others will be collected on site from high-traffic areas inside the station.
Surprises along the way
As part of its contribution to the competition, NanoRacks provided the winners with access to its existing products and services for supporting payloads on the Dragon capsule, in or on ISS, or in space, leaving the actual experimental work to the customer. Typical space payloads might require power, data, continuous air purge, deployment mechanisms, or other hardware.
Patricia Mayes, “Dream-Up Director” at NanoRacks, is responsible for drumming up educational payloads—anything students can dream up, from simple chemistry experiments to crystallography. Of course, the more payload owners know about what they want, the better. “If the customer knows what they want, or better yet, has it already in hand, it can take 9 to 12 months from project start to being ready to launch. If they don’t know what they want or it has to be developed, it could be anywhere from one to two years.”
In Project MERCCURI’s case, the original plan was to place the microbe samples into a standard growth medium akin to soup broth and then watch them over 30 days to see how they grow. Growth is recorded using a plate reader, which passes light through the microbe-infested broth and measures how the light is absorbed by the microbes (“growth kinetics”).
Russell Neches, a UC Davis doctoral candidate and one of the MERCCURI principal investigators (PIs), explained that microbiology samples have been done this way for 120 years. However, this particular method had not yet been used on ISS. “They’ve had a plate reader up there for a couple of years and have run some tests on it, but really haven’t done much science with it.” When it came time to set up this project, however, the team discovered that there was no way to measure growth kinetics for microbes immersed in liquid in space.
| The biggest trick to performing future work might be securing funding. |
On Earth, liquid stays at the bottom of a tube thanks to gravity. In space, any container holding liquid would have to be sealed, which prevents the liquid floating away but also prevents contact with air, potentially suffocating the microbes. The alternative was to place the microbes in a solid medium: agar, the jellylike substance you might see at the bottom of a high school biology class petri dish. The problem with this technique, however, is one of precedent. As Neches explained it, “We have 120 years of studies doing things in liquid.”
Neches eventually devised a solid-medium sample storage container with holes only one micron across—just large enough to let air in but not let the microbes out.
Perhaps the most difficult engineering challenge for Project MERCCURI had nothing to do with the experiment itself, but with the rocket. Darlene Cavalier explains: “We originally prepared the microbe collection activities so they’d be ready for launch in September 2013. The [CRS-3] mission experienced a few technical delays, shifting from December to March, and then finally April. While emotionally taxing, this turned out to be beneficial for our outreach efforts, as the national media coverage for our project swelled during the build up to each launch date.”
Launching and operations
Currently the Dragon is still berthed to the station, so it is uncertain what the final outcome of Project MERCCURI will be. However, to prevent the microbes from growing prematurely, the experiment was stored in the refrigerated, pressurized section of Dragon, wrapped in bubble wrap, and kept in a canvas cargo bag to protect it during spaceflight. As long as the refrigeration holds out, the microbes will be at rest until they’re released into their solid growth medium. Everything that can be done on the Earth side of the equation has been done. The rest is up to the astronauts on the Station and to SpaceX, when the ISS microbe samples return to Earth on May 18.
No bucks, no Buck Rogers
The biggest trick to performing future work might be securing funding. In addition to paying for some portion of the ride, payload owners usually must pay for engineering services to incorporate their work into Dragon and ISS as well as to handle the associated paperwork.
One unavoidable fact right now is that launching payloads into space is not cheap. Educational payloads can start at $30,000, which includes:
- Paperwork required for space transportation
- Handling of the safety review
- The space transportation to the space station
- Insertion of the payload into the NanoRacks Platform
- Power
- Data return
| Cavalier dismissed the notion that people don’t care about space or the ISS: “People still love space. When we invited several thousand people to participate in this research project, people jumped at the opportunity.” |
The good news is that NASA, the State of Florida, and other organizations have a vested interest in getting payloads up to ISS: NASA is keen to use ISS as a research site and to demonstrate its ongoing usefulness to the US taxpayer. Space Florida, the space business development arm of the Florida state government, wants space jobs in their jurisdiction. Besides the competition Space Florida and Nanoracks sponsored, NASA has multiple grants to fund experiments. They also work through the Center for the Advancement of Science in Space (CASIS), the entity charged with managing the ISS National Laboratory and bringing payloads and experiments to the ISS. CASIS-arranged payloads come from outside of the normal NASA research portfolio and are developed by commercial and educational entities not directly affiliated with NASA.
Additionally, payload servicing organizations like NanoRacks want business to enable access to space experimentation. To do that, they need paying customers like any good business. In addition to NanoRacks, other companies are providing payload development and integration services for future ISS payloads. CASIS provides a complete list of companies providing such services.
However, grants and goodwill aside, you still need money to launch your payload. According to Mayes, larger items, like Project MERCCURI—an internal experiment package that was 10 x 10 x 15 centimeters (about 4 x 4 x 6 inches)—might run $85,000 on NanoRacks. A full cubesat deployed from the ISS could run upwards of $100,000. Prices elsewhere can go even higher. Prices for suborbital launches aboard Virgin Galactic, XCOR Aerospace, Masten Space Systems, or other in-development services can be a bit less (XCOR, for example, is offering secondary payload space for about $20,000), but these platforms are not yet operational and the hardware obviously would be in microgravity for much less time. Before setting sights on having a payload on ISS, payload developers might want to consider carefully what they want to demonstrate and how much they are willing to pay.
Lessons learned
Now that Project MERCCURI has reached ISS, the team has time to pause and reflect on the experience. The UC Davis microbiology team had not done space-related research before, but given this experience, they might do so again. One of the PIs, Wendy—a Ph.D. candidate in biomedical engineering and a Science Cheerleader who cheers for the Oakland Raiders—wants to be an astronaut. David Coil, another of the PIs, believes that his team could do another space mission, “But it’d have to be something really cool.”
Darlene Cavalier, when asked what she learned about the space business, replied, “It’s predictably unpredictable.” More importantly, she dismissed the notion that people don’t care about space or the ISS: “People still love space. When we invited several thousand people to participate in this research project, people jumped at the opportunity. The opportunity to do research on the ISS and get microbes from the ISS is what inspired our own team to devote more than two tireless years of effort to this project.” Science Cheerleader and SciStarter are certainly interested in activating more citizen science research projects to go into space.
Lastly, Project MERCCURI’s unique combination of space, microbiology, publicity, and citizen science can provide a model for future collaborations between these various communities. Space projects incorporating work by private citizens provide the opportunity to do hands-on science that goes to ISS. This could provide a broader constituency of people willing to see the nation do grander things in space.