The ability of biomolecules—and entire organisms—to survive space has implications for a number of scientific questions: whether molecules from space could have seeded life on Earth, or whether life could spread among the inner planets following impacts. It also has practical implications, in that it dictates how careful we need to be in sterilizing hardware we send to other planets.
Chance gave some biologists access to a rocket, and they figured out a way to answer one of the questions. While prepping a sounding rocket for an experiment that briefly lofted some of their samples to space, they decided to put some DNA on the rocket’s exterior. And when it returned to Earth 780 seconds later, they were able to recover the DNA and put it to use.
Sounding rockets are typically used for payloads that only have to be put into space briefly. In this case, the researchers were putting cells into the payload of a VSB-30, a two-stage, solid-fueled rocket manufactured in Brazil. While doing so, they decided it would be interesting to see what happened to samples outside of the protection of the payload. So they obtained some DNA called a plasmid that carried two genes: one that provides antibiotic resistance to bacteria, and a second that encodes a green fluorescent protein.
They placed some of the DNA on the underside of the payload container, in the grooves of some screws on the rocket’s surface, and at specific locations on the nose of the vehicle. After all that was done, the VSB-30 was sent on a 13 minute trip from far-northern Sweden to space and back, after which the payload was recovered.
The researchers then simply washed the sites off with a sterile solution and check for the presence of DNA. Despite temperatures that were likely to have briefly reached 1,000 degrees Celsius on the exterior of the rocket, there was still DNA present. And, without any further cleaning up, that DNA could be inserted into bacteria and provide them with antibiotic resistance. When placed into cultured human cells, they glowed green. Sequencing the DNA revealed that it didn’t contain more than a handful of mutations, which may or may not be a result of its time in space.
All of which suggests that DNA might be a tougher molecule than it’s generally given credit for—tough enough to survive re-entry on any hardware that we don’t properly sterilize.
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