This week, NASA announced it was looking for a new ‘planetary protection officer’. Duties include safeguarding the Earth against alien contamination, and stopping us from contaminating the rest of the galaxy as well. We interviewed the now outgoing PPO back in Smith Journal volume 22. You can read the full profile below.
Cassie Conley describes herself as a typical American bureaucrat. She spends most of her days in a federal office “attending meetings, doing email, and writing or reviewing documents”.
But Conley is not some mid-level pencil pusher. She’s the NASA Planetary Protection Officer (PPO) – the person tasked to, as she puts it, “protect the Earth from life we might bring here from elsewhere, and protect other solar system objects from being contaminated by Earth life”. Planetary protection has been a concern for space wonks since 1956, when Sputnik 1 launched the space race. In 1967 the United Nations’ Outer Space Treaty stipulated that signatories incorporate planetary protection into their space programs. Fifty years later, there’s a PPO at every space agency.
Early planetary protection focused on fears that astronauts would encounter nasty alien microbes and infect the Earth, à la The Andromeda Strain; in fact, NASA originally dubbed it “planetary quarantine”. But by the 1970s the solar system seemed lifeless. NASA created a new Planetary Protection Office in 1976, which thereafter tasked a PPO with making sure our spacecraft don’t ruin other planets.
“Surprisingly, microbes from Earth seem to be able to tolerate conditions more extreme than any they were exposed to during evolution,” Conley says. Some could survive in space and alien atmospheres – then drop onto Mars, for example, contaminating or destroying landscapes or undiscovered alien life. So PPOs run calculations based on spacecraft materials and the likelihood of their missions encountering life, then contractors sterilise equipment until there’s negligible bacteria left.
This is not a sexy job. And it’s one Conley stumbled into by accident. In 2003, she was researching space biology for NASA and one of her experiments with nematodes wound up on the space shuttle Columbia during its explosion. Some of the nematodes survived, inadvertently offering data on life’s ability to naturally spread between planets via meteor strikes. That put her on the radar of John Rummel, the previous PPO. In 2006 he got her on an introductory one-year rotation – then left his post with only Conley to replace him.
Conley sees herself as a rote executor of international protocols. But since the discovery of water on Mars in 2015, her job has taken on new significance. As agencies worldwide prepare more ambitious explorations, some of which may seek life, global PPOs are about to get busy. “Access to locations on Mars, Europa or Enceladus – where Earth life might grow – requires that spacecraft be fully sterilised, which has not been done since the 1970s,” Conley explains. “The increasing interest in human missions poses a complex set of problems,” like how to ensure astronauts’ health and deal with them if they encounter alien microbes – a situation for which there are few modern guidelines. (Conley isn’t even sure when she’d be alerted to an encounter with alien life – that protocol isn’t clear.)
To a public and NASA eager to explore, Conley might seem like a one-woman buzzkill, making ambitious projects more expensive and difficult. Many believe contamination is inevitable, or may already have happened on Mars. But Conley’s confident in her ability to bring even these people around. She tells them to think about “that annoying guy in college who would drink out of the communal milk carton, making the milk go sour so nobody could have cereal for breakfast”. Nobody wants Earth to be that guy.
Still, Conley acknowledges that she’s in for an uphill battle, especially as private firms head for Mars. She believes PPOs have kept space relatively clean up till now. “But the more people who get involved,” she says, “the higher the chances of someone carelessly, or deliberately, breaching that protection.”