Earlier this year, planetary scientists got a pleasant surprise: a big boost in NASA’s budget, instituted at the direction of Representative John Culberson (R–TX), a leading member of the House of Representatives spending panel. But some of that money—$195 million, to be exact—came with a catch. It had to be spent on a robotic mission to land on Europa, Jupiter’s frozen moon, to search for signs of life.
Culberson’s lander has been somewhat controversial among scientists because it hasn’t gone through NASA’s traditional selection and vetting process. And today, researchers at an agency advisory meeting debated whether the congressional elections in November could bring a new lander-related headache: the defeat of Culberson, who is facing a tough re-election contest. If Culberson loses, NASA risks becoming “locked in” to an expensive and complicated project that lacks a key champion in Congress, one researcher worried.
By Culberson’s mandate, NASA had already begun to lay out plans for the Europa lander, which could launch by 2026. But at a panel session today at NASA’s Outer Planets Assessment Group, held in Pasadena, California, planetary scientists grappled with whether, and how aggressively, the agency should support the mission.
“The science goals of the Europa lander do not follow from our current knowledge of Europa,” said Chris McKay, a planetary scientist at NASA’s Ames Research Center in Mountain View, California. Although there is abundant ice for a lander to sample on Europa, he suggested, there is no concrete evidence of other ingredients necessary for life, such as carbon, nitrogen, biologically useful energy, or organic molecules. But given that the lander is already receiving money, he concluded in an about-face, scientists should support it. “A bad life detection mission is better than no life detection mission,” he said.
Others had a different view. It’s premature to design and build a lander before the Europa Clipper, which will orbit Jupiter while observing Europa, has had time to scout and map its surface and interior ocean in more detail, said Louise Prockter, director of the Lunar and Planetary Institute (LPI) in Houston, Texas. (She noted that her views did not represent LPI’s stance.) And the lander’s existence, based on the desires of a single congressman, make it fragile, she added. “The issue for the lander is that congressional support is coming from a single point. We don’t like single-point failures in our missions,” she said. “If that congressional support goes away, we are then locked in to a very large, very complex, very long mission.”
A Culberson loss wouldn’t pose a big risk to the project, countered Scott Bolton, principal investigator of NASA’s Juno mission around Jupiter and a planetary scientist at the Southwest Research Institute who works in Boulder, Colorado. “Even if Culberson loses, we know who’s going to come in, and he supports it,” Bolton said, apparently referring the lawmaker who could take Culberson’s place as the head of the spending panel that oversees NASA. (It could be a Democrat, if Republicans lose their House majority.)
At this point, Linda Spilker, project scientist of the NASA Jet Propulsion Laboratory’s (JPL’s) Cassini mission, tried to steer the conversation away from politics. But Bolton didn’t go along. “We’re trying to figure out what to do with the lander,” he said, “and the lander is in there because of the politics.”
At the meeting, scientists developing plans for the lander, who are largely based at JPL in Pasadena, relayed their newest design. Their efforts responded to a push, begun last year by NASA headquarters, to keep costs low. The plan, which would cost several billion dollars, calls for using three spacecraft to ferry the lander its destination. It would then land using a modified version of the sky crane that NASA has previously deployed on Mars. The battery-powered robot would dig a single trench into Europa’s surface with a robotic arm, exposing samples to a large suite of scientific instruments, while operating for more than 3 weeks. And it would focus on detecting biosignatures, rather than direct detection of life.
Scientists should not lose sight of how the Europa lander could excite the public, added Alfred McEwen, a planetary geologist at The University of Arizona in Tuscon. “This would be tremendously exciting mission for the general public,” he said, much more so than simply a series of flybys that will come from the Europa Clipper. And any mission that lands on Europa, even if it is not perfect or as complex as hoped, will produce fantastic science, added Cynthia Phillips, a planetary geologist at JPL. Though, she added, “maybe it’s not landing on Enceladus,” the water-spewing saturnian moon that, for many scientists, has supplanted Europa as a top target for detecting life.
Scientists at the meeting universally lauded the design work done by the lander team. As designed, the mission could yield great insights on the geology and chemistry of frozen ocean worlds. But what if, as one researcher said during a comment period, the most interesting thing about Europa seen by the Clipper is found on a cliff face? “We’re making a lot of assumptions in the design of the lander that we’ll live to regret once we get the Clipper data.”
There was no resolution to this debate, and the final outcome could depend on the results of the 2018 elections. Many scientists are looking for the next decadal assessment of NASA’s planetary science to consider the Europa mission, but by then NASA might have already invested a great deal of money. “And the fact is that Congress is excited about this,” said Kevin Hand, the astrobiologist at JPL who has helped develop the lander concept. “I think this is exactly the kind of mission, the kind of exploration, and potential big discovery, that NASA is chartered to undertake.”
*Correction, 18 September, 5:47 p.m.: A previous version of this story stated that the Europa Clipper would orbit Europa; to avoid harsh radiation, the spacecraft will instead orbit Jupiter and fly by Europa for many multiple views.