(Source: arstechnica.com)

DEEP IN THE SOLAR SYSTEM—A darkness has spread over the grim, airless field of ice that threatens to swallow us. Night has come to the nightmare glacier. But then we see the shiny spacecraft, with its four gangly legs extending outward to find purchase on the jagged ice. Within, scientific instruments begin to blink on, one by one. Soon, they will start sniffing for any hint of life on this most alien and mysterious of worlds in the Solar System: the Jovian moon Europa.

Through the HoloLens each of us wears, we watch this simulation of what might happen about 15 years from now on the icy, forbidding moon. The otherworldly illusion is shattered when a voice booms out; it’s John Culberson, a conservative Republican politician from Texas. He wants to know what happens if one of the blinking instruments fail. Not to worry, he is told, all of the spacecraft systems are redundant. “Good,” Culberson replies. “The immensity of what you’re doing is too important in human history. You don’t want to miss this chance.”

Europa truly does represent a singular chance. Crossing 800 million kilometers with a sizable, robust payload will require vast sums of money—there won’t be a second chance. But Europa represents a gamble in another sense, too. No one knows whether NASA will discover a frozen, dead world far from the Sun or if the organization will make the most profound of discoveries just below the ice.

During the last decade, NASA has recast its human and robotic space exploration programs around the search for life both in our Solar System and beyond. Much of this effort has focused on Mars, which is relatively close to Earth and may have harbored life in the past. Culberson has pushed the agency further to seek extant life. He and a lot of scientists believe the best place to find extraterrestrial life in the Solar System lies in deep oceans below Europa’s inhospitable surface.

During the last five years, Culberson has bull-headedly shoved about half a billion dollars through Congress to give NASA’s elite planetary probe scientists and engineers a chance to land on Europa. Now, in late February, he has come to the Jet Propulsion Laboratory, in the hills just north of Los Angeles, to visit the wizards here who conceived the Voyager spacecraft, developed Cassini and Galileo, and landed Curiosity on Mars. What progress, he wondered, had they made toward teasing out the secrets of Europa?

  • NASA/JPL-Caltech

  • NASA/JPL-Caltech

  • NASA/JPL-Caltech

  • NASA/JPL-Caltech

  • NASA/JPL-Caltech

  • NASA/JPL-Caltech

Quite a lot, actually. During more than five hours of briefings in “Left Field,” a room named for its encouragement of ideas out of left field, scientists and engineers explained to Culberson how they plan to tackle the challenges of landing on Europa. A year ago they weren’t even certain it could be done, but now they’re increasingly confident.

“We’ve looked at most of the things that used to really bother us,” said Dara Sabahi, a lead engineer on the project. “There were a lot of gotchas, but today I can say that—and I don’t say this lightly—we are confident we can make this work. I believe the technologies are in reach, and the risks that bothered us are manageable.”

Notably, the JPL team thinks it has solved the vexing problem of planetary protection, the concern that any stray microbes from Earth could contaminate Europa’s ecosystem. The solution has come straight out of the pages of science fiction—the lander mission will be the first interplanetary spacecraft to carry a self-destruct mechanism.

Before launch, the spacecraft’s exterior will bake at high temperatures to remove all contaminants, while the delicate scientific instruments inside are shielded. Then after the spacecraft reaches Europa and finishes its work, an incinerator will burn the scientific innards at 500 degrees Celsius. “What a glorious way to go out after discovering life for the first time on another world,” Culberson says, approvingly.


Of all the myriad, multicolored balls of gas, dust, rock, and ice that spin around the Solar System, Europa offers the greatest extremes within just a few kilometers—from highly lethal on the surface to potentially lush below. Few worlds are as infernal on the surface as Europa, where the area sits utterly exposed to the vacuum of space and ever marinates in the deadly radiation of Jupiter. And yet, this same radiation may be critical for life in the oceans below.

As ionizing radiation from Jupiter’s magnetosphere strikes the water ice on the surface of the moon, it breaks down water molecules into hydrogen and an OH molecule. Over time, these OH molecules combine to form hydrogen peroxide. One of the scientists who spoke to Culberson, Kevin Hand, has a lab in which he has created an extremely cold, irradiated environment like that on the Jovian moon. With this “Europa in a can” experiment, he has found that hydrogen peroxide on the surface decays into hydrogen and oxygen.

Although the hydrogen molecules are light enough to escape into space—Europa has one-seventh the Earth’s gravity—the oxygen molecules remain on the surface. Europa’s surface age appears to vary between about 10 million and 100 million years old. This means some process resurfaces the top of Europa, periodically subducting the ice shell into the ocean. “We’ve done some calculations on how much oxygen is being delivered into the oceans below, and it’s not too hard to get Europa’s ocean oxygenated to a level where you could start supporting multicellular life, if not more,” Hand said.

The subglacial Lake Vostok, beneath the continent of Antarctica, may offer an analog of sorts for life in Europa's ocean.

Scientists must work with limited data, because the one NASA probe that studied Jupiter and its moon system extensively, Galileo, didn’t prioritize the ice-covered world. But from Galileo’s data, scientists estimate the ice shell may be a few kilometers to a few tens of kilometers thick. Below that, an ocean probably extends more than 100km down, and scientists anticipate that Europa harbors more water than all of the oceans, lakes, rivers, and glaciers on Earth combined.

The external pull of Jupiter’s gravity tugs on the core of Europa, and this tidal flexing provides a source of internal heat. It seems likely that structures similar to hydrothermal vents, which on Earth support thriving colonies of life, line the bottom of the ocean. So Europa has oxygen, energy, and lots of water. Certainly, no one expects to find whales, sharks, or other large sea creatures in Europa’s oceans. Chemosynthetic microbes seem far more likely, but really, we have no idea.

Culberson, of course, believes the chance of life existing on Europa is not only high, but he believes that there may well be more advanced life forms. During a discussion of the potential for plumes outgassing from the ocean below and lander sites, he offered the following suggestion to the mission’s science team. “I want you to land where it’s going to snow krill down on your head,” he enthused.

A prudent, but costly, pathway

Europa will not give up its secrets easily or cheaply. Two years ago, engineers at the lab proposed a complex mission that combined a small lander along with a mission that would make multiple flybys. Eventually, the engineers decided this was too much for a single mission—too heavy, too risky, and ultimately not enough of a scientific payload.

Moreover, planetary scientists wanted time to extensively study data collected by a flyby spacecraft, which is now known formally as the Europa Clipper. This would allow them to find an ideal place to land on the moon, whether near plumes (if they do, indeed, exist as some Hubble Telescope observations suggest), “fresh” ice, or other areas of interest to maximize the chance of finding life with a lander. This is the prudent pathway preferred by NASA, with a flyby mission before a lander so the agency won’t be flying blind. And Clipper will provide an amazing set of eyes, flying to within 25km of the surface in long, looping orbits and returning images with a resolution of up to one-half meter per pixel. By comparison, even the best images of Pluto captured by New Horizons were about 70 meters per pixel.

The Hubble Space Telescope has found evidence of plumes emanating from Europa, but nothing definitive.

Prudence has a cost, however. Clipper remains on target to launch five years from now, and it’s budgeted to cost $2.7 billion in real year dollars. That price tag does not include the launch vehicle and a few other expenses. Total costs, therefore, will reach as much as $3 billion to $4 billion for the flyby mission; the lander will come in a second mission. This has caused some consternation in the planetary science community. While exploring Europa rates atop their “wish list” for planetary exploration, does the icy moon deserve two flagship missions?

Moreover, some scientists wonder whether Clipper could itself find signs of life. It will certainly look, but generally the odds of finding life on Europa, if it exists, will be significantly higher if a spacecraft lands and makes in situ measurements. “The most important goal is searching for life,” Hand said. “That is admittedly extremely hard to do with remote sensing.” Even if Clipper got lucky and could sample plumes, it might collect nanoliters of material. As a baseline, the lander mission will collect and investigate five samples of seven milliliters each, a million times more material. Finding life, therefore, will almost certainly require testing the ice.

The Clipper will serve another purpose, too: testing technology needed for the lander. When the second Europa mission launches in 2024 or 2025, the lander spacecraft will carry a module similar to the Clipper called the “carrier,” which will serve as a communications relay between the lander and NASA’s deep space network.

Because the carrier will derive from Clipper hardware, the JPL engineers estimate the total cost of flying it will be about the same as the Clipper despite the lander spacecraft’s larger size. That means another $3 billion to $4 billion, so all told getting to Europa and examining its surface will cost NASA, and the US government, as much as $8 billion.

“This will be tremendously expensive,” Culberson acknowledged. “But worth every penny.”

Even for the powerful chairman of the Commerce, Justice, Science, and Related Agencies subcommittee of House Appropriations, this is a lot of money. Even now, during the planning and early hardware development phase of both the flyby and lander missions, the money is starting to add up. For fiscal year 2018, alone, Culberson will need to find $495 million to continue moving both missions along. Instead of cutting other missions from NASA’s planetary science budget, he wants to sell Europa to his colleagues on Capitol Hill as a worthy addition. For that, he has a plan.

A messianic zeal

Culberson’s passion for Europa can be traced to roots in both family and faith. As a child in the 1960s, he and his brother read popular science magazines, built telescopes, and shot off model rockets in Houston as nearby Johnson Space Center planned and flew the Gemini and Apollo programs. The gee-whiz in his attitude toward science is genuine, but it only partly explains his passion for Europa. To understand his messianic zeal for the cause is to know that the congressman believes God created the universe, filled it with life, and called John Abney Culberson to help reveal its majesty.

After the Europa briefings in late February continued through a working lunch, Culberson joined another politician, Adam Schiff, for a town hall at JPL to rally the scientists and engineers there. It was easy to understand Schiff’s presence. The democratic House member’s district includes La Cañada Flintridge, where JPL is based.

But Culberson? He represents a well-to-do west Houston district. By all rights, he should most concern himself with Johnson Space Center, where the astronauts train. And while Culberson professes an interest in human spaceflight, he clearly feels more at home at JPL and visits the California center often.


  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

  • NASA/JPL/University of Arizona

The Houston congressman drove this point home during one session devoted to the Clipper mission. The project’s manager, Barry Goldstein, flashed a standard slide that NASA always prepares for a politician—a map of the United States with dots on it to represent all the field centers, businesses, and academic centers involved in a project. About half of the states were represented so far in the flyby mission. “Our goal is to try and populate at least the contiguous 48 states,” Goldstein explained. “I doubt we’ll get that far, but we’re making pretty good progress.”

Culberson interrupted him. Texas only had two stars, one in Austin for the University of Texas and one for the Southwest Research Institute in San Antonio. Nothing in Houston; Johnson Space Center wasn’t involved. Was he mad? Not exactly. “That’s always good, but you’ve got to remember that I’m very different,” he said. “I don’t think of NASA as a jobs program. It’s a strategic national asset, essential for the human spirit.”

Perhaps this sounds like bluster. But if NASA really goes to Europa and lands there, it seems entirely possible that not a penny of the $8 billion will get spent in Culberson’s district, perhaps not even in the entire Houston area.

Selling Europa

Other politicians concern themselves a great deal more about such on-the-ground benefits. US representatives and senators from Alabama and Florida care a lot about NASA’s big Space Launch System rocket, which is being designed and developed at Marshall Space Flight Center in Alabama and will launch from Kennedy Space Center in Florida. Culberson’s counterpart in the Senate, the chairman of the Appropriations subcommittee over NASA’s budget, is Richard Shelby, an Alabama Republican.

A few years ago Culberson began insisting that the mission to Europa launch on an SLS rocket. It is defensible to say that such a launch brings value, in that the powerful SLS rocket will get a spacecraft to Jupiter far more quickly than any other booster. But there is a more pragmatic reason. Culberson needs Shelby’s agreement on NASA’s budget, and Shelby needs missions for the SLS rocket. As it turns out, more than just about any other conceivable mission, Europa justifies the costly SLS.

The Juno spacecraft, weighing about 3.5 tons, launched in 2011 on top of an Atlas V rocket. It reached Jupiter almost five years later. The Clipper spacecraft weighs 6 tons, and the Block 1b variant of the SLS will throw it to Jupiter in just 2.7 years, directly, with no gravity assists. The lander mission will weigh even more than the Clipper, and still it will reach Jupiter in less than five years.

Arguably, the lander can’t be done without the SLS. Sitting on the launch pad, a Block 1b version of the SLS rocket will weigh 3,000 tons. That is “wet mass,” as most of the weight is liquid hydrogen and oxygen propellants. The spacecraft represents just a tiny fraction of the overall mass, a few tons. Of this, the lander preliminarily weighs a mere 477kg, or 0.016 percent of the launch mass. The scientific payload is about a tenth of that. Put another way, the rocket will expend 99.999 percent of its mass to get a handful of scientific instruments onto Europa.

With SLS, the scientists get their data faster. The Congressional contingents from Alabama and Florida are happy, too, because their booster shines. And Culberson gets much needed Senate support for his expensive quest to find life on a frigid moon deep in the Solar System.

Git ‘r done

Culberson had hoped the lander mission might be ready to launch just a year after Clipper, in 2023, but during the February briefings the JPL engineers cautioned that they needed extra time to develop the incinerator for planetary protection, as well as other new technologies. With enough funding, 2024, or more likely 2025, was doable. Culberson can live with these kinds of delays.

“When it comes to the designing and building of the spacecraft, I will not push you guys—OK, maybe a gentle push—because I want you to get this right,” the native Texan said. “But I won’t tolerate delays from Washington. I’m going to continue beating on the bureaucrats. That’s what I do for a living. So don’t rush, but git ’r done.”

For several years this has been the reality of the relationship between Culberson, NASA headquarters, and JPL, which takes its direction from Washington. Several times during the February briefings, he asked the scientists and engineers whether NASA HQ had been responsive, helpful, and moved expeditiously. Of late, it had. Whereas Culberson had a Invalid%20post%20id%20for%20story%20sidebar

“>fractious relationship with former NASA Administrator Charles Bolden, who dragged his feet on a Europa mission, he says acting administrator Robert Lightfoot has been “extremely supportive.” Later, Culberson told me he has been meeting with Trump administration officials, including Vice President Mike Pence, to ensure their support.

The long-term future of the two missions seems at least moderately secure. True, Culberson’s deep red Republican district, which he’s represented since 2001, has trended a little bit blue during recent years. But the Tea Party Republican still managed to handily defeat two primary opponents who came at him from the right in 2016, and he won the general election by a margin of 56 to 44.

If he can continue winning elections, Culberson has four more years as chairman of the NASA budget subcommittee and then he might be in line to chair the full Appropriations committee. This is important, because while the flyby mission is now far enough down the line in development to be on fairly secure footing, the lander mission remains vulnerable without his full backing and proselytizing in Congress.

Living fast, dying young

The lander will undoubtedly find a sterile world, at least at first. A pristine microbe, even if it were accustomed to a vacuum and temperatures just 100 Celsius degrees above absolute zero, would die in days to weeks from Jupiter’s ionizing radiation. But scientists believe markers of life in the oceans below would show up on the surface, especially if the spacecraft lands in the right location.

By burrowing down just 10cm below the surface, the lander will reach an area where the effects of radiation are negligible, increasing the odds of finding fragments of life. To this end, the Europa lander’s sampling arm will come equipped with a “cutter,” essentially a small rotary saw. At Europa’s surface temperature, the ice is considerably harder than granite, so engineers have tested 35 different blade types on 25 different surfaces, including several variations of cryogenic ice, and powered them with three different drive trains.

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

  • Europa Lander Science Definition Team Report

The nominal surface mission will last 20 days, with the scientific instruments protected within a radiation-hardened case. Ultimately, the mission’s length will be determined by the batteries on board, which have a capacity of 45kWh. (A MacBook Pro operating at full capacity, 24 hours a day, would consume about that much energy in a month.)

This should provide plenty of time for the collection of five samples. A recently released report from the lander mission’s science definition team, led by Hand, goes into detail about the various instruments on board, from a microscope capable of seeing cells down to 0.2 microns to two kinds of spectrometers that will corroborate any evidence of life. An “announcement of opportunity” for scientists to submit proposals to build the instruments should come this August, with a final selection in May 2018.

In addition to searching for life, the lander will have two other secondary missions. It will attempt to characterize the habitability of the oceans below from factors such as the chemistry of the water to the thickness of the ice shell. The lander will also determine the physical characteristics of the world in order to inform future expeditions, including a penetrator that may attempt to reach the ocean. Culberson seemed pleased: “We’re living fast. We’re dying young. And getting a lot of great science done.”

A secret weapon

Thanks to the ominous warning in Arthur C. Clarke’s novel, 2010: Odyssey Two, much of the science and technical community shares Culberson’s fascination with Europa. But for the general public, the icy moon remains largely an unknown. Eight billion dollars to peck at the ice on some moon around Jupiter? What is the sense of that? As he works on his peers in Congress, Culberson will eventually have to convince Joe the Plumber, Ken Bone, and the rest of America about the relevance of Europa, too.

For this mission, he has a secret weapon. During the briefings at JPL, Culberson brought a friend with him, the famed Director James Cameron. The two men share an interest in exploring the depths of oceans, and periodically Cameron peppered the JPL presenters with questions about batteries, the chemistry of Europa’s ocean, and so forth. But mostly, he came as Europa’s storyteller-in-chief. “If you want to talk to the world, this man knows how to do it,” Culberson said of his friend. It’s true in some sense. Titanic and Avatar are the two highest-grossing movies of all time.

At one point during the presentation, Hand displayed the cover of the report written by the lander team, which depicts the spacecraft at rest on Europa with Jupiter rising lustrously above the horizon. It recalled the iconic Apollo 8 image of Earth rising above the Moon, which helped sell the lunar landing program to the American public. “You need to do that picture,” Cameron interjected. “It should be a given. You want that picture, about 30 degrees above the horizon. It’s mandatory.”

Hand noted that since Europa is tidally locked to Jupiter, only half of the moon ever sees the gas giant. You really wouldn’t want to constrain your landing site just for a photograph, he explained.

“It had better be a damn interesting landing site,” Cameron retorted. After this exchange, the group of scientists and engineers inside Left Field laughed. During that moment, Cameron turned to whisper to Culberson. “Nobody ever likes to hear that stuff,” the director said. “But it’s what sells this kind of program.”

From the congressman’s nod back to his friend, it seemed pretty clear that the most important person in the world when it comes to exploring Europa had heard Cameron’s message. Loud and clear.