SpaceX sends major science payload to the ISS

SpaceX has now made five successful rocket landings. As part of the ninth Commercial Resupply Services flight, the SpaceX team recovered a booster from a successful launch Monday — the second stage touched down, in accordance with the mission plan, at 12:53 AM EDT. CRS-9 is due at the ISS on Wednesday morning, with a several-ton payload of supplies and experiments in tow. Dragon is also bringing an international docking adapter which will make it easier for future manned missions to dock with the ISS. This includes future crewed Dragon flights, as well as the Boeing Starliner. While CRS missions aren’t manned (yet!), that doesn’t mean today’s mission didn’t bring any life to the party. This time, in addition to the crew supplies and science hardware, the CRS-9 flight will bring microbes from Chernobyl to the International Space Station.

Much of the science payload is equipment to be tested, including a machine for testing whether we can sequence DNA in microgravity. It’s not that we think it’s impossible — DNA sequencing just requires electrical current, but the way we currently do sequencing also relies on Earth’s familiar gravity, so we need another method if we’re going to do sequencing in space. There’s also an experiment called OsteoOmics that looks at which genes are transcribed in bone that’s been kept in mag-lev weightlessness on Earth versus bone cells kept in freefall weightlessness, which is what occurs aboard Station.

NASA also sent up a phase-change heat exchanger that they’re alpha testing. It could make heating and cooling in space easier by providing thermal inertia. The test build will compare water and wax to see which works better.  Wax’s thermal properties and overclocking potential has actually been explored for use in smartphones and other technology platforms, though we’ve yet to see shipping systems that used the technique.

The fungus comes from locations within and around the Exclusion Zone at Chernobyl. Originally gathered by Lawrence Berkeley National Lab as part of a different experiment, these eight species have been living in culture, so they aren’t themselves radioactive. But two of the species, Cladosporium sphaerospermum and C. cladosporioides, actually seem to have a taste for radiation. They grow toward it with a decisive preference.

Cladosporium cladosporioides, one of the fungi 

from Chernobyl that’s heading into space. Image: Medmyco via Wikimedia Commons

Clay Wang and colleagues hope the radiophilic microbes will provide some clue that will help humans survive in space. These special-snowflake fungi have many tactics that they employ to soak up and mitigate the dose of radiation they receive, including producing a lot of melanin, which can scavenge free radicals from the ambient fluid bath.

While the radiation environment aboard the ISS station is nothing like the radiocontamination surrounding the ruined nuclear plant, astronauts still experience elevated levels of radiation exposure while they’re in space. Wang hopes that the elevated dose will convince these fungi to start showing off their repertoire of radiation compensation tricks, explaining to Popular Science, “Microorganisms only make certain things when they need to. We want to see if they actually make new compounds in space.”

“From an overall perspective, this is just part of the rich stream of research going on on the space station, from human research, biology, physical sciences investigations and things for exploration technology,” said Julie Robinson, chief ISS program scientist, during a briefing Saturday. Falcon 9 is due back from the ISS in about a month, and we’ll keep you updated on its next endeavors.