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Europa Clipper
NASA plans to fly nine instruments on its proposed mission to Europa, but the mission’s Congressional patron would like to add a lander as well. (credit: NASA/JPL)

What price Europa?

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It’s a good time to be involved with, or simply a fan of, a mission to Jupiter’s moon Europa. Last week, NASA announced the selection of a suite of nine instruments that will fly on a mission there the agency plans to launch in the 2020s. Later this week, the House of Representatives is expected to approve a spending bill for fiscal year 2016 that will provide $140 million for that mission, far above what NASA asked for in its budget request.

So, what’s not to like? In the zero-sum game of NASA budget politics, a gain for Europa is a loss for other programs, particularly Earth science. The Europa mission has a powerful champion in a key House member, but his desire to search for life on Europa and other icy worlds of the outer solar system might well end up alienating other scientists.

Instruments to probe the big question

On May 26, NASA announced its selection of instruments that would fly on its as-yet-unnamed mission to Europa. Out of 33 proposals it received last year, NASA selected nine instruments. NASA also selected a tenth instrument that will receive funding for technology development and possible selection on a future mission, but isn’t currently slated for the Europa mission.

“All of these instruments are designed to increase our rather limited knowledge of Europa, and they’re doing that by helping us probe the big question: ‘is Europa habitable?’” said Niebur.

The nine instruments are diverse. There are wide- and narrow-angle cameras, magnetometers to infer the depth the salinity of Europa’s subsurface ocean, spectrometers to measure the composition of the moon’s surface, and a radar to probe Europa’s icy crust above its subterranean ocean. The spacecraft also carries an ultraviolet spectrograph to search for plumes of water erupting from the surface scientists previously detected in Hubble observations.

That set of instruments, though, has the same mission. “All of these instruments are designed to increase our rather limited knowledge of Europa, and they’re doing that by helping us probe the big question: ‘is Europa habitable?’” said Curt Niebur, Europa program scientist at NASA Headquarters, in a May 26 press briefing announcing the instrument selections.

Those instruments will take on that question from different directions. For example, the infrared spectrometer will help scientists measure the composition of “brown gunk” seen on the moon’s surface. (“And that is our state-of-the-art term for it,” Niebur added.) That material, he said, appears to be associated with the freshest surface features on the surface, and is likely material from that subsurface ocean brought up with water. “If we can determine what the brown gunk is, we can then understand what is in the water, what is in the oceans of Europa,” he said.

He emphasized, though, that the purpose of the instruments is to determine if Europa is habitable, but not if it is, in fact, currently inhabited. “We don’t have a life defector,” he said. “We currently don’t even have consensus among the scientific community as to what we would measure that would tell everybody with confidence that this thing you’re looking at is alive.”

Slow start versus fast start

The selected instruments, Niebur said, will get about $10 million in the next year and $110 million over the next three years to mature their design. “That will get us to a point where we reach a key decision point where we decide if we’re going to continue on with the instruments, or if some of them are no longer ready,” he said. At that point, he said, NASA will have a cost estimate for the full development of the instruments.

The overall mission is still in its “pre-formulation” phase, but will likely be based on a concept called “Europa Clipper” where the spacecraft goes into orbit around Jupiter and makes dozens of close flybys of Europa rather than go directly into orbit around the moon (see “The gift of a Europa mission may have a cost”, The Space Review, February 9, 2015). Jim Green, director of NASA’s planetary sciences division, said the mission would enter its formulation phase and become an official program by the end of the current fiscal year in September.

“We expect it to be launched in the 2020s,” Green said. “Whether it’s mid, or a little early or a little later, needs to be worked out.”

A formal cost estimate for the mission is still some time in the future, as the mission concept is refined and goes through an initial series of reviews. Green said concepts NASA is currently looking at for the mission have costs “on the order of $2 billion without the launch vehicle,” he said, in line with previous estimates for Europa Clipper.

However, NASA’s current budget foresees a slow start for the mission: the agency requested $30 million for Europa in 2016, and $285 million through 2020. NASA says that supports a launch of the mission some time in the 2020s, but Green was vague about exactly when it would launch.

“We expect it to be launched in the 2020s,” Green said when asked at the briefing about the mission’s schedule. “Whether it’s mid, or a little early or a little later, needs to be worked out based on a much firmer cost estimate and a profile that would support it.”

An appropriations bill to be debated by the full House this week would accelerate that schedule. The Commerce, Justice, and Science (CJS) spending bill, which funds NASA among other agencies, sets aside $140 million of NASA’s $18.5 billion budget for a Europa mission.

Moreover, the bill would require a launch of the mission no later than 2022, and require the use of the Space Launch System (SLS) heavy-lift launch vehicle for the mission. NASA has looked at using SLS for the Europa mission—its performance would cut the mission’s travel time roughly in half over an Atlas V—but had not planned a decision on the vehicle for some time.

That provision in the bill is the handiwork of Rep. John Culberson (R-TX), chairman of the CJS appropriations subcommittee and far and away the biggest Congressional advocate for a Europa mission. He has, in essence, become the mission’s patron, earmarking funding for the mission in the bill when NASA has not requested it, or requested less.

Agency officials hedged when asked if, even with a surplus of funding, a Europa mission could be ready by 2022. “They could be ready in the early 2020s,” Niebur said of the selected instruments, “but that’s also dependent upon how much money is in the budget for us to give them for that work.”

A crusade for life

The report accompanying the CJS funding bill goes further. It would require NASA to establish a new initiative called the “Ocean World Exploration Program” that would include not just the Europa mission but future spacecraft concepts to go to Saturn’s largest moon, Titan, which has liquid hydrocarbon seas, and Enceladus, an icy moon of Saturn that also has a subsurface ocean of liquid water. The program’s goal, according to the report, would be “to discover extant life on another world” using a mix of small, mid-sized, and flagship missions.

While steeped in the science of Europa, Culberson approaches its exploration with a religious zeal. “I believe the good Lord seeded the entire universe,” he said.

That quest for life, spearheaded in Congress by Culberson, becomes clearer after reading a recent Houston Chronicle article about work on the mission. The article is based on a visit by Culberson (and Chronicle reporter Eric Berger) to JPL earlier this month, where they sat down with JPL engineers and NASA officials to discuss planning for a mission.

In that story, Culberson appears more enthusiastic about a Europa mission than even those at JPL working on it. “Where’s the magnetometer?” he asked at one point in the discussion, according to the article. “You’ve got to have a magnetometer.” It’s hard to imagine any other member of Congress getting that involved in the details of a spacecraft mission design—or, for that matter, even knowing what a magnetometer is and why it would be useful at Europa.

At the JPL meeting, Culberson is seen pushing to include a lander of some kind on the Europa Clipper mission. The JPL team there, including Adam Steltzner, who led the development of the Curiosity Mars rover’s landing system, said a small lander could be done for an additional billion dollars.

While some scientists supported an impactor probe that would be simpler and less expensive to build, Culberson instead advocated for a soft lander, one equipped with tools to scoop up samples and analyze them, including a microscope. “Why go all that way if you’re not going to answer the most important question?” Culberson asks in the Chronicle article.

That question, of course, is whether Europa in inhabited—the same question that NASA officials say they can’t answer now since there’s no “life detector” instrument or technique that would unambiguously answer that question.

Culberson doesn’t appear to be deterred by such technical or scientific challenges. While steeped in the science of Europa, he approaches its exploration with a religious zeal. “I believe the good Lord seeded the entire universe,” he tells the Chronicle.

That zeal has its cost. The $110-million increase in funding for Europa accounts for a little more than half of the $195-million increase in planetary science funding in the House bill over the administration’s request. The bill includes extra funding for NASA’s 2020 Mars rover mission, and also funds the Lunar Reconnaissance Orbiter and Opportunity Mars rover, which were not funded in the request and faced cancellation.

The bill, though, slashes Earth science funding: a cut of nearly $265 million from the administration’s request of $1.95 billion. The cuts include a mission proposed by NASA to fly a thermal infrared Earth science instrument as a gapfiller, given the lifetime of a similar instrument on an existing Landsat satellite; the bill provides no funding for it.

The planetary science community has had to tread carefully on this issue. On the one hand, they want to support any increase in the budget for planetary science, which has suffered significant cuts in recent years by the administration. On the other, they don’t want to be seen as celebrating an increase at the expense of Earth science, setting the stage for conflicts between the two communities, and turning a Europa mission’s rising profile, and budget, into a target.

And it’s already becoming a target. “While directing an impractical level of funding toward the Jupiter Europa mission, the bill cuts important NASA Science programs by more than $200 million compared to the President’s Budget,” wrote Shaun Donovan, director of the Office of Management and Budget (OMB), in a letter to Rep. Hal Rogers (R-KY), chairman of the House Appropriations Committee, May 19.

Donovan, in the letter, specifically mentioned the cuts in Earth science, saying that they are “jeopardizing Earth Science missions that are helping us understand how our climate is changing and respond to earthquakes, droughts, and severe weather events.”

It’s unlikely that the full House will make significant changes to that or other portions of the NASA bill this week. However, the Senate, which lacks a Europa evangelist anywhere near as enthusiastic as Culberson, may be a different story. Sen. Barbra Mikulski (D-MD), the top Democrat on the Senate Appropriations Committee, stated in late April she would seek to increase NASA’s overall budget, and mentioned Earth science, but not planetary science, as one of her top priorities.

But if the Europa mission does fly, thanks to the funding offered by Culberson and with the lander he desires, and does detect life on Europa, NASA’s Jim Green knows what he would do. “I would immediately retire,” he said, laughing. “If there is life in the solar system, and in Europa in particular, it must be everywhere in our galaxy and perhaps in the universe.” For some scientists, and others like Culberson, answering that question might be worth almost any price.


ISPCS 2015