All your secrets belong to us*

We are finally heading to the most intriguing and unknown frontier of the solar system.

If you've been waiting for a real exploration mission into the unknown, here it is.

10/09/2024, Eric Berger, arstechnica.com

I hate to break this bad news to you, but you and I will not live forever, dear reader.

Perhaps we can hope to catch our breath for a few more decades. But this is not enough to meaningfully see any worlds orbiting other stars. These mysterious balls are too far away, both in space and time; the immensity of this galaxy is too great, and the rhythm of human life is too short compared with the slow rhythm of cosmic time. So we space lovers must make do with what's in our backyard.

If you're of a certain age, say half a century or less, you may feel like you missed out on the golden age of space exploration when humanity first set foot in this backyard. Baby Boomersborn in time to not only see what the lunar surface looked like, but also watch people walk on it in real time, were lucky indeed.

What an era it was! Before this, everything except the Sun and Moon were dots in the night sky. In 1962, Mariner 2 studied Venus for the first time. Mariner 4 flew past Mars a couple of years later. Then there were Voyagers, which passed by Jupiter in 1979, Saturn in 1980 and 1981, Uranus in 1986 and Neptune in 1989. And don't forget about the Viking landers in the mid-1970s, which proved there were no little green men on Mars. Boomers saw it all during their lifetimes, revealing the solar system as one of their greatest hits.

But if you haven't been there, don't despair. Over the last decade or so we have begun to discover some previously unexplored new horizons. Ten years ago, Europe's Rosetta spacecraft provided unprecedented images of the comet, and then its tiny Philae lander descended to the surface to reveal a winter wonderland. The following year, NASA's New Horizons spacecraft flew past Pluto and its moon Charon and revealed all sorts of wonders, including actual ice volcanoes.

And these recent treats are just appetizers to the greatest unknown world in our solar system yet to be explored, a place that holds dark secrets that we can currently only poke blindly with dull knives. I'm talking, of course, about Jupiter's ice-covered moon Europa. Beneath a thick layer of ice lies a huge, warm ocean. Scientists believe that conditions at the bottom of this vast global sea are not much different from conditions near hydrothermal vents on the bottom of Earth's oceans, where life on our planet may have originated. We can only guess at the answers to basic questions, such as how thick is the ice? How deep is the ocean? What secrets can be explored in its dark depths? Could marine life really exist there?

The magic of this moment is that we are finally on our way. If you wanted to live up to the real mission to discover an unknown but alluring world, then this is what you need.

This weekend, the Falcon Heavy rocket will launch with the Europa Clipper spacecraft worth 4.25 billion dollars. This mission is unlikely to provide a definitive answer to the question of whether life exists in Europa's oceans. But Europa Clipper will tell us whether it could exist and answer many other questions about the icy moon. The most interesting thing is the unknown wonders that she will discover. We can't even guess at them, but we can be sure that if all goes well, Clipper will be an exhilarating mission that will take your breath away.

But this mission might not have taken place.
This is the story I want to tell here.

It all started decades ago

After two Voyager flybys in 1979, NASA sent a special probe called Galileo to Jupiter in the 1990s. The spacecraft made several flybys of Europa during its nearly eight years in orbit around Jupiter, and data from the mission indicated the likely presence of a water ocean beneath the moon's icy surface. In the nearly three decades since then, planetary scientists have had little information beyond these tantalizing clues. They were desperate to know more.

Almost immediately after Galileo's first data on Europa was sent back to Earth in 1996, then-NASA administrator Dan Goldin asked scientists at the Jet Propulsion Laboratory in California if a small mission dedicated to studying Europa was possible. Fitting into Goldin's “faster, better, cheaper” ethic, he wanted to design a spacecraft that would carry just 27 kg of scientific instruments to Europe, about the same weight as a suitcase that could be checked as luggage on a plane.

“This was the beginning of the Europa orbiter concept,” said science writer David Brown, author of “Mission“, which details the history of the Europa Clipper mission.

The original science goals outlined during the development of the orbiter's mission—to study the composition of Europa's ice shell and ocean, the geology of the world, and to search for and study any plumes emanating from the ocean below—remain more or less the same with Clipper. However, as often happens with deep space missions, the budget doubled. NASA's turn-of-the-century science director, astrophysicist Ed Weiler, shut down the fledgling Europa program.

But scientists were still interested. In 2003, the National Research Council published my first “decadal review”, a document through which the scientific community determines research priorities for NASA. Over the years, these decadal reviews have become influential tools for guiding NASA policy. In this first review, scientists recommended that NASA create a “large-scale” mission to study Europa.

NASA Administrator at the time, Sean O'Keefe, sought to develop a new generation of spacecraft powered by nuclear reactors in what he called project “Prometheus”. He believed that a mission with Europa as the main target would be an ideal test for this technology, and thus the Jupiter Icy Moons Orbiter was born. It was a very ambitious mission. A typical spacecraft consumes on the order of several hundred watts of power. This probe, powered by a nuclear reactor, would have about 100,000 watts of energy.

The Jupiter Icy Moons Orbiter was bold in other ways, such as using a landing component to directly sample Europa's ice. Unfortunately, the mission also became insanely expensive, with a budget exceeding $20 billion. When O'Keefe was replaced by a new administrator, Mike Griffin, in 2005, the Jupiter Icy Moons Orbiter was frozen.

Galileo has generated incredible interest in Europe. At first, NASA tried to do a quick and cheap mission. The agency then worked on the most ambitious spacecraft concept ever put forward. Both failed. A decade was lost.

A new champion emerges

In 2000, conservative Texas lawyer John Culberson won his first election to the US House of Representatives. For a time, he focused on local issues such as freeway construction in the Greater Houston area. However, after the Jupiter Icy Moons Orbiter mission was cancelled, he was furious.

Most people in Congress, to the extent that they care about NASA, do so for narrow interests and jobs in their districts. For Culberson, it was the Johnson Space Center, which was located in a nearby area. But Culberson was also deeply interested in planetary exploration and wanted to be involved with NASA's first mission to search for life on another world. So he became a proponent of funding NASA's center on the opposite side of the country, the Jet Propulsion Laboratory, which led the agency's robotic research efforts.

As a member of the House Appropriations Committee, Culberson began writing NASA's budget for funding for the ongoing Europa Orbiter study.

During this period, as a science reporter for the Houston Chronicle, I began running into Culberson at various events around the city. He was both a conservative Christian politician and a lifelong science buff. The skeptic that I am, wondered if his interest in science was driven by a need to ingratiate himself with voters, given that the Houston area has a large biomedical community. However, eventually I began to realize that he was completely sincere. He was fascinated by the solar system and wanted to know more about its origins and whether it contained life on worlds other than Earth. We bonded over this common interest.

Meanwhile, the mission to Europa was just beginning. In 2007, NASA began exploring mission concepts for Europa and Ganymede in the Jupiter system, as well as Saturn's moons Titan and Enceladus. Working with international partners two years later, NASA eventually selected a combined mission in which the US space agency built the Europa orbiter and the European Space Agency built the Ganymede orbiter (this European mission was eventually launched under the name JUICE in 2023). The part that NASA was responsible for was known as the Jupiter Europa Orbiter.

However, a year later, new NASA administrator Charles Bolden was looking for ways to cut the agency's budget. By now you probably already know what happened. Of course, Jupiter Europa Orbiter's budget ballooned to over $3 billion. And there was one more problem – Mars began to occupy a leading position in the agency’s sphere of interests.

“For the first time in 20 years, Mars was put into competition with the outer planets,” Brown said. – In a painful budgetary environment, the Mars Sample Return mission was approved. As a result, the Jupiter Europa Orbiter died.”

Culberson was unhappy again. But this time he was soon able to do something about it.

Let's look behind the curtain

In 2012, NASA initiated a new series of studies to once again decide on a mission to Europa. The main contender that emerged from this process was a spacecraft capable of making multiple flybys of Jupiter's moon, and it became known as the Europa Clipper. Scientists realized that it was not practical to build an orbiter because the spacecraft would have a short lifespan due to constant exposure to intense radiation coming from Jupiter. After making dozens of flybys, Clipper could break into Jupiter's inner system, collect data from Europa, and then transmit it back to Earth when the spacecraft is further away from the harsh radiation environment around Jupiter.

Beginning in fiscal year 2013, Culberson began adding funds to NASA's budget specifically for the development of the Clipper mission, although NASA had not committed to launching the program.

“We'll only have one chance in our lives,” he told me that year, explaining his efforts to get NASA to greenlight a mission to Europa after nearly two decades of hesitation. – We have one chance. I want to make sure that you and I are still here to see the first tube worms and lobsters on Europa.”

NASA could not afford to ignore Culberson, who was no longer a junior congressman. In December 2013, U.S. Rep. Frank Wolf, a Republican from Virginia, announced he would not seek re-election in 2014, leaving Culberson the favorite to replace him as chairman of the appropriations subcommittee that oversees NASA. This essentially gave Culberson control of the agency's cash flow.

This happened in January 2015. Now chairman of the all-important budget subcommittee, Culberson began making periodic trips to the Jet Propulsion Laboratory in California. To the chagrin of NASA's senior management and public affairs officials, Culberson decided to invite me to the sessions, which lasted a day or two. There were no restrictions. I was able to attend all the meetings, listen to the discussions and even sometimes participate. Moreover, at Culberson's insistence, all this was recorded.

Let me explain how rare this opportunity is. Journalists typically learn about space exploration by interviewing sources, attending press conferences, and reading scientific articles. But to be in the room where this is happening? This simply doesn't happen. But Culberson invited me backstage for detailed discussions where mission planners and management at NASA's California facility explained what they were doing, why they were doing it and where they needed political help. It was a revelation to see how such missions were carried out and to see the power of government in action.

During these meetings, Culberson, universally referred to as “Mr. Chairman” during these visits, made suggestions and pushed scientists to make bold decisions in design and instrumentation. He always asked how much funding they needed and then provided it during the next budget cycle. All of this happened, more or less, because Culberson believed the Clipper was important to the country.

Eventually, NASA management accepted the inevitable and officially committed to the Clipper mission. Culberson no longer needed to include language like “NASA should fund” the Clipper in budget requests because the agency was in business. By the time Culberson lost reelection in 2018—a midterm election in which Democrats gained seats in response to then-President Donald Trump's unpopular first term—Clipper was advanced enough to be safe.

Brown said many people at JPL and NASA headquarters in Washington, D.C., are responsible for creating the Clipper concepts and maintaining the idea. Among them are scholars and leaders such as Charles Elachi, Carla Clark, Bob Pappalardo, Louise Proctor and Kurt Niebuhr. But Culberson stands apart for what he did for the mission.

“Without John Culberson, none of this would have happened,” Brown said. “When you boil it down to dollars and cents, he's the guy who paid for this thing and pushed it far enough for it to take off.”

What will Clipper do?

The launch of Clipper on a completely expendable Falcon Heavy rocket unfortunately marks only the beginning of the mission. The spacecraft will take 5.5 years to reach the Jupiter system. During this time, it will cover a mind-boggling 1.8 billion miles (2.9 billion kilometers).

Once at Jupiter, the spacecraft will complete 80 orbits of Jupiter, including 49 flybys of Europa. Some of these passes will place the spacecraft within 15 miles (25 km) of the moon's surface, giving us incredible views of the ice and any plumes.

Of course, plumes would be incredibly exciting because they would provide direct evidence of what the subsurface ocean is like. There is some fragmentary evidence from Galileo, as well as observations from the Hubble Space Telescope, that such plumes can break through ice through cracks. But we just don't know for sure.

Clipper is the largest spacecraft that humans have ever launched into deep space. It never got a nuclear power source, so it has massive solar panels that are 45 feet (14 meters) long and 15 feet (4.5 meters) high. On a court of this size one could safely play basketball.

The spacecraft is equipped with a sophisticated array of instruments, including a powerful ice-penetrating radar that will study the boundary between the ice crust and the ocean and possibly identify pond- or lake-like formations there.

Although this is not a life-detection mission, scientists could be very lucky and find signs of life in the plume or on the surface. However, in all likelihood, they will simply characterize the world and its ocean, intending to return in the (distant) future with a lander to take in situ measurements and perhaps discover life.

However, the most exciting thing of all is that the Clipper is truly flying into the unknown. This is a mission of pure discovery of one of the most exciting worlds near Earth. Whenever we explore a new place in space, nature always surprises us. “We've always discovered things we couldn't imagine,” Bonnie Buratti, deputy project scientist for the Clipper project, said during a recent briefing. Indeed it is.

Europe has many secrets, and we are finally going after them.

*- reference to Arthur C. Clarke’s novel “2010: Odyssey Two”.

Quote from the novel:
“All these worlds are yours, except Europe.
Attempt no landing there.
Use them together.
Use them in peace.”

Translation: Alexander Tarlakovsky (blog tay-ceti)
Original: We're finally going to the Solar System's most intriguing but unexplored frontier

NASA and SpaceX plan to launch Europa Clipper on October 14

11.10.2024, Laura AguiarNASA

NASA and SpaceX now plan to launch Europa Clipper no earlier than Monday, October 14th. In the wake of Hurricane Milton, teams continue to conduct inspections to ensure flight readiness.

Original: NASA, SpaceX Targeting NET Oct. 14 for Europa Clipper Launch