Chatfield High School senior, Dominika Mroz inoculates algae in the school’s greenhouse under the supervision of her science teacher, Joel Bertelsen. Ms. Mroz and fellow students are preparing an experiment scheduled to go to the International Space Station in May. Their experiment will grow algae in a bioreactor to determine if they can produce hydrogen and lipids in space. NREL researcher Nick Sweeney is mentoring the students and assisting with the experiment. Photo by Dennis Schroeder / NREL

Almost two years ago, on June 28, 2015, the rocket carrying experiments from Chatfield High School to the International Space Station disintegrated 139 seconds into its flight. That could have put an end to the collaboration between the students and researchers from the Energy Department’s National Renewable Energy Laboratory (NREL), but a second-chance flight is scheduled to take off from Florida on May 31.

“I had an inkling we might get to go again,” said Joel Bertelsen, a science teacher at Chatfield who bore witness to the failed 2015 launch. “There was hope even then.”

Mr. Bertelsen will return to Florida with four liters of algae and the scientific acumen developed by both current and former students to make a four-chamber bioreactor. If all goes well, the two experiments it will house will yield results in space similar to what NREL scientists have encountered here on Earth. One strain of algae, Chlamydomonas reinhardtii, will produce hydrogen that can be used to power fuel cells while the other, Chlorella vulgaris, will make lipids.

NREL research dating back to the late 1970s opened the doors to the potential of algae being used as an alternative energy source. That could prove immensely helpful in space, particularly on long voyages when the ability to generate fuel would be critically important. When deprived of sulfur, C. reinhardtii will switch from producing oxygen to making hydrogen. Research has proven that nitrate starvation triggers C. vulgaris to go into lipid production mode, and those lipids can then be converted into biofuels.

A science teacher at the Jefferson County school for 23 years, Mr. Bertelsen was involved in NREL’s Energy Institute for Teachers. He also worked as part of a research team on the Energy Department’s Academies for Creating Teacher Scientists, a program for teachers to learn about renewable energy and energy efficiency so that they can incorporate what they’ve learned into their science, technology, engineering, and math (STEM) lesson plans. When Mr. Bertelsen heard about a competition that would send student experiments into space, he reached out to Alexandra Dubini after reading about her work with C. reinhardtii at NREL.

“This lab has been working on hydrogen production for a long, long time, and specifically one condition, which is sulfur deprivation. He wanted to try that,” said Dr. Dubini, who spent seven years as a research scientist at NREL before leaving the laboratory last year. She’s now at the University of Cordoba in Spain. “I said, ‘Sure, why not?’ So we tried to replicate an experiment we did at NREL to see if that works in space.”

Dr. Dubini helped Mr. Bertelsen write the grant proposal that ended up securing funds from the Center for the Advancement of Science in Space (CASIS). CASIS manages the U.S. national laboratory aboard the International Space Station, and chose Chatfield as the school that would send experiments there.

Mr. Bertelsen turned to NREL’s staff for a solution to an immediate problem: “How will I grow algae? My background is in aerospace engineering,” he said. “I’m fine with biology, but it was not my forte.”

That’s where Nick Sweeney’s help proved invaluable. A research technician in NREL’s National Bioenergy Center Algal Biomass Research laboratory, Mr. Sweeney was able to pull strains from about 500 different types of algae. He’s the one that suggested the students also experiment with C. vulgaris. He supplied Mr. Bertelsen with samples, visited Chatfield, helped design experiments for the students, and assisted in setting up the bioreactor. “The main thing was to get these engineering students excited about this STEM-type work – get them excited for their college careers,” Mr. Sweeney said.

Leading up to the original launch, students in Mr. Bertelsen’s Intro to Engineering class embarked on parallel experiments with the algal strains. When he met with CASIS executives in November 2014, he presented their work on the two experiments and said no decision had been made about which one should go to the International Space Station. The reaction? Send both.

Crucial to the school’s experiment was developing the bioreactor. Close enough wasn’t good enough. Mr. Bertelsen said a typical classroom engineering project requires students to design something, build and test it, and then redesign it to fix any flaws. If the redesign doesn’t work, it’s time to move on to something else. That couldn’t be the case when designing something heading into space.

What will go into space is a small box, 10 cm wide by 15 cm tall. Inside is a four-chamber bioreactor designed to keep the algae spinning, with C. reinhardtii in two chambers and C. vulgaris in the other two. Squares of a special tape that changes color from tan to gray to signal the presence of hydrogen will be affixed to the chambers housing the C. reinhardtii. The C. vulgaris will lose its greenish hue and turn yellowish as the algae begins to produce lipids.

The experiment will last about 24 days, after which the algae will be frozen and returned to earth for comparison to the samples that remained here.

“I won’t get my biomass sample for a couple of months,” said Mr. Sweeney, who has been working with NREL scientist Sharon Smolinski on the hydrogen-producing algae. “It will be interesting to see how much their biomass changes from their baseline. Will there be much of a change? We don’t know.”

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