When Rep. John Culberson (R-TX) lost his seat on Tuesday, NASA lost one of its biggest fans in Congress. And many in the science community are now wondering about the fate of one of the congressman’s pet projects — a lander to travel to Jupiter’s icy moon Europa. Culberson has long had a fascination with searching for life on Europa, and as the chair of the House Appropriations Subcommittee that funds NASA, he has been in the unique position to appropriate money specifically for a lander.
Now that Culberson is about to leave public office, the Europa lander will no longer have its champion, making its future at NASA uncertain. NASA never formally requested a lander for Europa, and the president’s latest budget request noted that the administration had no intention of funding such a program. No other lawmaker seems to be as passionate about the project, nor in the same position to keep the program alive.
Plus, there are some in the science community who wouldn’t be upset to see the mission go. In fact, a few experts are concerned that sending a lander to Europa right now is premature, as we don’t know enough about the moon’s surface to successfully touch down on it. And there’s frustration over the fact that the lander was born from a politician rather than scientific consensus. “The Europa lander was always Culberson’s,” Emily Lakdawalla, the senior editor at The Planetary Society, tells The Verge. “It’s a mission that came out of Congress as opposed to a mission that came out of the [science community].”
However, some think now is the time to begin planning a lander to Europa, as these missions take such a long time to pull off. And such a mission would keep the world engaged in the exploration of the Solar System. “The thing that finally convinced me that it was really a good idea was the public outreach of this,” Alfred McEwen, a planetary geologist at the University of Arizona who studied concepts for a Europa lander, tells The Verge. “Landing is really exciting to the public.”
Despite the divide over a Europa lander, many planetary scientists agree that Jupiter’s moon is an enticing place to visit in our Solar System. There’s evidence that Europa might harbor a giant liquid-water ocean underneath its icy crust. And it seems likely that this water periodically erupts from the moon in the form of plumes, spewing the contents of the ocean out into space. Given that liquid water is so crucial for the existence of life here on Earth, many wonder if it’s possible that life might lurk in the watery depths of Europa’s ocean, too.
This intriguing possibility captured Culberson’s attention more than a decade ago, and he has advocated searching for life on Europa for most of his time in office. We reached out to Culberson’s office for comment, but did not receive an interview. In the early 2000s, he pushed for a Europa mission that was ultimately canceled by former NASA administrator Mike Griffin. Then in 2014, Culberson became chair of the House Commerce, Justice, Science, and Related Agencies (CJS) Appropriations Subcommittee, which provides funding for NASA. And thanks to his efforts, he’s helped NASA get funding for not one, but two missions to the moon — despite pushback from multiple administrations.
That second mission is called Europa Clipper. The project calls for a spacecraft that will fly by Europa repeatedly for more than three years, coming within 16 miles of the moon. That way we can get an up-close view of the moon’s surface and possibly fly through the particles spewing from underneath the crust. If we’re lucky, scientists could get a better understanding of whether Europa has the right chemicals to support life.
However, Europa Clipper will never actually touch Europa, and simply flying by was never enough for Culberson. He wants to search for life, and he’s convinced landing is the key. “It’s obvious that the only way to confirm there’s life in the oceans of Europa is to land on the surface and sample the ice,” Culberson told Science Magazine. In 2015, Culberson visited NASA’s Jet Propulsion Laboratory, according to Ars Technica, where a group of engineers presented him with a way to land on Europa, based on how NASA landed the Curiosity rover on Mars. Energized by the idea, he included language in the final Congressional spending bill that year, stating NASA had to include a lander and a Europa orbiter. “When it’s written into law, it becomes illegal not to fund it that way,” Casey Dreier, director of space policy for the Planetary Society, tells The Verge.
In response to these Congressional directives, NASA has studied concepts for a Europa lander, one designed specifically to look for life. And the space agency has called on ideas for instruments that could be included on such a spacecraft. But, NASA has never actually requested funding for the project. Still, Culberson keeps giving the space agency money for it, forcing NASA to work on the lander. For fiscal year 2019, Culberson appropriated $195 million for the lander. NASA didn’t ask for any money.
To be fair, the Europa Clipper mission also had a hard time getting NASA’s endorsement, too. Culberson kept giving NASA money for it until the space agency finally gave in and officially made it a long-term commitment. For fiscal year 2015, NASA requested $15 million to studies for a Europa mission for the first time. Thanks to Culberson, NASA got $100 million instead.
But a fundamental difference between the two missions is that Europa Clipper has strong support within the scientific community. Sending a spacecraft to fly by Europa was considered a top priority in the 2011 planetary decadal survey — a report from the National Academies of Sciences that details all the Solar System missions that planetary scientists think deserve top funding. “The decadal survey is a crucial piece of information because it represents a lot of really intelligent, really knowledgeable people coming to consensus on best next steps,” Aileen Yingst, a geologist at the Planetary Science Institute, tells The Verge. “It doesn’t mean it’s always correct, but it does represent the best consensus our community can come to.”
The Europa lander, on the other hand, was not included as a top priority in the decadal survey. “That’s why the lander is in a much more uncertain position when Culberson leaves Congress,” says Dreier. “Because you don’t have any sort of institutionalized support for the concept.” And while most scientists agree that sending a lander to touch down on Europa’s surface is crucially important, some think that it’s too soon to start designing such a vehicle now. Even though we’ve sent a few spacecraft near the vicinity of Europa, we still don’t have detailed high-resolution imagery of the surface nor do we have much data from the space environment around the Moon. And it’s hard to design a lander for a terrain and environment you don’t know that well. “I actually put in a proposal for a potential instrument to be on the lander, and I struggled with writing a proposal because we have so many unknowns,” says Yingst.
That’s why conventional exploration methods usually call for an orbiter or vehicle to fly by a world first before landing on it. That way scientists can get detailed maps of a place to better aid lander designs, as well as help choose where the lander should touch down. A good historical example lies in NASA’s Viking landers, which were sent to Mars in the mid-1970s to look for signs of life. Prior to their landing, NASA had successfully put a spacecraft called Mariner 9 in Martian orbit, which provided the first detailed images of the Martian surface. That helped pick a spot for the Viking spacecraft to land.
And Europa Clipper will provide all of that critical mapping info, too. But the way things are planned now, Clipper is meant to launch as early as 2022, with the lander launching in 2024 (if rocket schedules permit). And with a travel time of about six years to Europa, Clipper won’t reach the moon before the lander is supposed to be ready to go. The concern is that Clipper might find something that the finished lander isn’t equipped to handle. “If you don’t understand the situation well enough, that’s a recipe for failure, and so what’s the urgency to do this before we’re ready?” says Lakdawalla. “We have a mission on the books that’s going to give us the information we need in order to be able to do a Europa lander. Let’s do Europa Clipper first, and I think Europa will be a very high priority for a lander mission in the future.”
The counter argument is that waiting for Clipper to get data from Europa will take a longtime. Clipper is slated to reach the moon in the late 2020s, and if we wait until then to start the design, that means that we won’t reach the moon’s surface until maybe the 2040s. “The people who want Europa lander would like it to happen in their professional lifetime,” says McEwen. He argues that it’s possible to work on the lander now, and simply design it to handle numerous different terrains. “It’s always possible that what you really want to sample is out of reach,” he says. “But you have to be able to take risks in this business, so it’s a trade off.”
And of course, there’s always money to consider. The Europa lander is likely going to cost billions of dollars, and it’s unclear what that final number will be. With any expensive space mission, there’s always a concern that one giant project could eat up all the funding in a single NASA directorate, making it hard for other missions to get off the ground. A similar scenario is happening right now with NASA’s James Webb Space Telescope, which is billions of dollars over budget and many years behind schedule, making it harder for other astrophysics projects to get funding. No one wants a repeat of that, especially with a lander that not everyone is on board with.
Plus when it comes to studying ocean worlds in our Solar System, there are many to choose from. Saturn’s moon Enceladus is also thought to harbor a subsurface ocean, and some think that the world may be a better place than Europa to search for life off of Earth. “Maybe we don’t want to necessarily put all our eggs in the Europa basket because there are more ocean worlds out there,” Amanda Hendrix, a senior scientist at the Planetary Science Institute, tells The Verge. “In terms of studying ocean worlds, it’s interesting we have a lot of them to choose from in the Solar System.”
But what was unique about Culberson is that he was finding money for the Europa projects, without taking it from other NASA missions. The money does come from somewhere within the federal budget, of course, but the Europa projects didn’t seem to come at the expense of other space science initiatives. And at this moment, there are no obvious replacements for Culberson who will take up the call for Europa. “It’s rare to find a champion for space science in general, and it’s rare to find a champion so well positioned and powerful for space science,” says Dreier.
Still, 2018 isn’t over yet. Culberson is still in office and it’s possible he could negotiate some last-ditch funding for the Europa projects before the end of the year. NASA is being funded through a continuing resolution that lasts until December 7th. It all depends if lawmakers can come to an agreement in the next few months on how funds should be appropriated for fiscal year 2019. But once Culberson leaves, it seems likely the funding for the Europa lander will dry up — and that could mean more waiting before we ever touch down on the mysterious moon’s icy exterior. “This is part of the deal of doing science in a democracy,” says Yingst.
Quelle: THE VERGE