Europa Clipper has has a key Review

A NASA mission to a potentially habitable moon of Jupiter has cleared a major review despite uncertainty about when, or how, it will launch.

NASA announced Aug. 19 that it had formally confirmed the Europa Clipper mission to proceed into its next phase of development, known as Phase C. That will cover final design of the spacecraft, followed by assembly and testing.

“We are all excited about the decision that moves the Europa Clipper mission one key step closer to unlocking the mysteries of this ocean world,” Thomas Zurbuchen, NASA associate administrator for science, said in a statement announcing the milestone.

Europa Clipper will enter orbit around Jupiter and make dozens of close approaches to Europa, one of the planet’s largest moons. Europa has an icy surface, below which most scientists believe is a deep ocean of liquid water. Combined with the interior heat source that keeps the ocean from freezing, and the presence of organic compounds, Europa has the basic requirements to support life.

While the programmatic milestone Europa Clipper achieved, known in NASA parlance as Key Decision Point C, is the point where NASA sets the schedule and budget for the mission, exactly when Europa Clipper will launch is not yet clear. In the statement announcing the mission’s confirmation, NASA noted that current plans have the spacecraft ready for launch as soon as 2023. However, the mission has a formal launch readiness date of 2025.

That uncertainty is linked to how the mission will be launched. The mission’s preferred launch option is the Space Launch System, which will allow the spacecraft to travel directly to Jupiter without the need of gravity assists, arriving within three years of launch. Language in appropriations bills for fiscal year 2019 and prior years also directed NASA to use the SLS.

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The IG office of NASA is asking for flexibility for the launch of the Europa Clipper.  This includes which launch vehicle will be used and when.  If NASA selects any other launch vehicle, the arrival at Europa will be delayed by over 5 years, if not more.  For that reason, I'd have to say I hope Congress declines the request.

NASA IG has Concerns About the Europa Missions

Despite early-stage robust funding, NASA is facing serious management and schedule challenges in its ambitious Europa Clipper program that will send an orbiter and lander to Jupiter’s ice covered moon beginning in 2023.

“Specifically, NASA’s aggressive development schedule, a stringent conflict of interest process during instrument selection, and an insufficient evaluation of cost and schedule estimates has increased project integration challenges and led the Agency to accept instrument cost proposals subsequently found to be far too optimistic,” the audit found.

“Moreover, Clipper has had to compete with at least four other major JPL-managed projects for critical personnel resources, causing concern that the project may not have a sufficient workforce with the required skills at critical periods in its development cycle,” the report said.

The audit also noted that the Europa program’s biggest backer, John Culberson, no longer chairs the House appropriations subcommittee. The Republican Congressman from Texas was defeated in his reelection bid last year.

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Sputtering and detection of large organic molecules from Europa

Sputtering and detection of large organic molecules from Europa 

Authors: 

Johnson et al 

Abstract:
Mass spectroscopy of bio-molecules by heavy ion induced sputtering, which became a practical laboratory procedure, was also suggested as a potential tool for spacecraft studies of targets of interest in astrobiology. With the planning of new missions to Europa, there is renewed interest in the possibility of detecting organic molecules that might have originated in its subsurface ocean and can be sputtered from its surface often intact by impacting energetic heavy ions trapped in Jupiter's magnetosphere. Here we review the laboratory data and modeling bearing on this issue. We then give estimates of the ejection into the gas-phase of trace organic species embedded in an ice matrix on Europa's surface and their possible detection during a flyby mission.

Europa Almost Assuredly has Watery Plumes

NASA has confirmed “statistically significant evidence” from the Hubble Space Telescope indicating the presence of salty watery ejecta plumes from the Jovian moon Europa. The announcement lends further proof for the existence of a deep, saline ocean under Europa’s icy surface and creates new urgency and objectives for NASA’s upcoming Europa Clipper mission in the mid-2020s.

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Europa Mission may Have Budget Squeeze in FY 2017

While NASA says its support for a mission to Jupiter’s moon Europa is now aligned with Congress, project officials are preparing for a possible “squeeze” on mission funding in the next fiscal year.

In presentations at an Aug. 11 meeting of NASA’s Outer Planets Assessment Group (OPAG) in Flagstaff, Arizona, officials involved with what’s widely known as the Europa Clipper mission said they are looking for ways to cut costs in 2017 while keeping the mission on track for a 2022 launch.

“There is this squeeze in FY17 that we have,” said Bob Pappalardo, the mission’s project scientist at the Jet Propulsion Laboratory, said. “We’re asking the instrument teams and various other aspects of the project, given that squeeze, what will it take in the out years to maintain that ’22 launch. We’re actively pursuing that question as we speak.”

Pappalardo didn’t elaborate on the budget details, but the administration’s request for the mission in its 2017 budget proposal, $49.6 million, is far less than the $175 million it received from Congress in 2016. There is uncertainty in Congress as well: a House appropriations bill for fiscal year 2017 offers $260 million for the Europa mission, yet a Senate bill, while “supportive” of the mission, does not explicitly allocate any funds for it. Neither bill has been passed by either chamber.

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The Europa Missions and the SLS

Europa, the icy Jovian moon with a subsurface liquid water ocean heated by tidal forces, presents a tremendous opportunity for scientific exploration and offers tantalizing possibilities for the search for extraterrestrial life. Despite the stark warning issued in Arthur C. Clarke’s 2010: Odyssey Two to “attempt no landing there,” NASA has been working on a dedicated mission to Europa, which now involves a lander, for more than three years.

This mission’s profile has undergone considerable evolution since Congress first allocated money in 2013 to finance it, including a policy mandate to utilize the heavy-lift Space Launch System for launch.

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Europa Mission Getting Enthusiastic Support From Congress

Congress has been a lot more excited than NASA about a mission to explore Jupiter’s frozen moon Europa, giving the agency more funds than it has requested for a mission that will be much more ambitious than originally planned.

For Fiscal Year 2016, Congress appropriated $175 million for the Europa mission, far above the $30 million the space agency had requested. It also mandated that a lander be added to a spacecraft originally intended to orbit the planet.

And under Congressional mandate, the Europa mission must be launched by NASA’s heavy-lift and very expensive Space Launch System, whose main purpose is to send human missions beyond low Earth orbit.

All of this has NASA revising its plans as it strives to meet a July 2022 launch readiness date. The Government Accountability Office says meeting that date could be difficult $3 to $4 billion project despite its recent funding boost.

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Will the Europa Mission Take the Place of the EM-2 SLS Launch?

As NASA and its contracted partner agencies press forward toward the debut launch of the Space Launch System (SLS) rocket in 2018, the U.S. space agency is beginning to look toward preliminary planning and test objectives for the EM-2 mission of the SLS Program, which is expected to take place sometime in the opening half of the 2020 decade.

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With SLS now legally mandated as the launch vehicle for Europa Clipper, the issue of testing the EUS in-flight prior to EM-2 could be rectified if SLS launches the Europa Clipper mission in 2022 ahead of EM-2.

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How to Detect Europa's Subsurface Ocean Through Radio Waves Using a Lander

Prospects of Passive Radio Detection of a Subsurface Ocean on Europa with a Lander

Authors:

Romero-Wolf et al

Abstract:

We estimate the sensitivity of a lander-based instrument for the passive radio detection of a subsurface ocean beneath the ice shell of Europa, expected to be between 3 km - 30 km thick, using Jupiter's decametric radiation. A passive technique was previously studied for an orbiter. Using passive detection in a lander platform provides significant improvements due to largely reduced losses from surface roughness effects, longer integration times, and diminished dispersion due to ionospheric effects allowing operation at lower frequencies and a wider band. A passive sounder on-board a lander provides a low resource instrument sensitive to subsurface ocean at Europa up to depths of 6.9 km for high loss ice (16 dB/km two-way attenuation rate) and 69 km for pure ice (1.6 dB/km).

NASA Seeking Ways to Avoid Using SLS for Europa Mission(s)

Faced with a congressional mandate to add a lander to a planned mission to Jupiter’s icy moon Europa, NASA is considering launching the lander separately from the main mission.

In discussions Feb. 1 at a meeting of NASA’s Outer Planets Assessment Group in San Antonio, Texas, agency officials said they are considering how to add a lander to a mission under development to make multiple flybys of Europa, even though the lander will weigh significantly more than the main “clipper” spacecraft.

Curt Niebur, outer planets program scientist at NASA Headquarters, said at the meeting that the biggest challenge of adding the lander to the Europa mission is its mass: about 8,000 kilograms, to accommodate the propellant needed to land the spacecraft softly on the surface. He added that estimate was “very rough” based on the limited studies of lander concepts to date. By comparison, the clipper spacecraft alone would have a mass of only about 5,000 kilograms.

That additional mass would drive the selection of the launch vehicle, requiring the use of the Space Launch System. “If we co-manifest the lander and clipper, we’re only on SLS,” he said. “It’s still a slow boat, so to speak: you’d still do inner solar system gravity assists.”

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Future Planetary Exploration on the Europa Mission Lander

While there’s at least eight years until it launches, this has been a pivotal year for developing NASA’s Europa mission. Last spring, NASA selected a rich and highly capable instrument set. This summer, following a design concept review, the mission moved from concept studies to an official mission. And just last week, Congress directed NASA to expand the mission by adding a small lander as well as launch the mission by 2022 and use the Space Launch System. These latter aren’t just suggestions: they are the law.

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NASA Working on Lander as Part of Europa Mission

NASA is very publicly planning a mission to Europa in the 2020s, one that will soar over the intriguing moon dozens of times. Yet the reality is more thrilling. Quietly, the same engineers who masterminded the daring Curiosity landing on Mars in 2012 have been plotting how best to drop a lander onto the nightmare glacier. In early November, they presented their preliminary findings for a 230-kg lander to the one person in the world who can, and who dearly wants to, make that happen.

“I told them to do whatever it takes,” said Representative John Culberson after meeting with the NASA scientists. “All of humanity is going to want to know what’s under the ice.”

A God-fearing, cowboy-boot wearing conservative Texas Republican, Culberson is far from a household name. But as chairman of the House Appropriations Subcommittee with oversight of NASA’s budget, he has the final say on the agency’s budget in the House. As much as anything else he has ever wanted in his life, Culberson yearns for NASA to land on Europa. And with the federal purse in hand, he’s doing everything possible to make it happen.

Culberson isn’t the first to fall under the moon’s spell. In Greek mythology, Zeus, the Greek counterpart to the Roman god Jupiter, abducted the Phoenician princess Europa and made her the queen of Crete. The moon is named after her. In the seminal science fiction series Space Odyssey, novelist Arthur C. Clarke recognized Europa’s special place in the Solar System. At the end of the series’ second novel, 2010: Odyssey Two, a ship sent to Jupiter appears to receive a message from aliens: “All these worlds are yours except Europa. Attempt no landing there.”

Sorry HAL, we’re going. It’s difficult to imagine a more compelling mission for NASA in the next 10 to 15 years than the exploration of Europa. NASA touts its human “Journey to Mars,” but in reality the most astronauts will accomplish by the mid-2020s is a repeat of the Apollo 8 flight around the Moon, which already happened in 1968. Likewise, while Curiosity awed the world, it was the eighth probe NASA has successfully landed on Mars. Cold, dry, and probably lifeless today, Mars no longer seems all that exotic.

Europa, by contrast, is undiscovered country. NASA last visited the Jupiter system in the 1990s and early 2000s with the Galileo spacecraft. Galileo snapped images of Europa during 11 flybys, but everything about those photos ended up limited. The best of those pictures had a resolution of only about 10 meters per pixel. The spacecraft stored those images on a tape recorder with a capacity of 114 megabytes, but a flawed rewind mode hampered even that modest device. Additionally, Galileo’s closest approach to Europa brought the probe only to within about 200 km of the moon’s surface.

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NASA/APL's Europa Clipper Mission Moves Ahead, Selects Solar Panels Over RTGs

Designers of a proposed NASA mission to study the icy and potentially habitable Jupiter moon of Europa have decided to use solar panels rather than a nuclear power source for the spacecraft, while keeping spacecraft’s launch options open.

In an Oct. 3 presentation at the 65th International Astronautical Congress here, Europa Clipper deputy project manager Thomas Magner of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said that using large solar panels for the mission was both technically viable and less expensive than a radioisotope thermoelectric generator (RTG).

“For the last two years, we did extensive risk reduction work looking at whether solar is feasible,” Magner said. “We found that solar works fine, so our final decision about two months ago was to go to solar.”

Those tests included subjecting solar cells to a range of temperatures and radiation conditions the spacecraft would experience during the mission. Engineers also examined whether the large solar panels, with an area of 50 square meters, would cause jitter that would adversely affect the spacecraft’s scientific instruments.

Europa Clipper would not be the first solar-powered Jupiter mission: NASA’s Juno spacecraft, launched in 2011 and scheduled to go into orbit around Jupiter in July 2016, also uses solar panels. Magner said they tested solar cells used for Juno, exposing them to a wider range of temperatures to reflect the different trajectory that Europa Clipper would take to reach Jupiter.

A solar-powered Europa Clipper would be less expensive than one that used an RTG, Magner said, although he did not quantify the difference in costs. It would eliminate the need for an environmental impact statement that is required for nuclear-powered spacecraft and launch approval from the director of the Office of Science and Technology Policy. It would also free up constrained supplies of plutonium-238, the isotope used in RTGs, for other potential missions.

Magner said after his presentation that using solar power would increase the spacecraft’s mass in order to accommodate the panels and structures, although it remained well within current design margins. A few other tweaks would be needed to the spacecraft’s design to incorporate the solar panels, he said.

While NASA has not yet decided to develop Europa Clipper or any other mission to Europa, Magner said the project passed a NASA-sponsored mission concept review in September “with flying colors” and predicted the agency would move ahead with it.

“We expect later this year for NASA to select us as the mission they want to go forward with to Europa, and we’ll get a new start early next year,” he said.

If NASA does choose to proceed with Europa Clipper, it will defer a choice of launch vehicle for several years. One mission design could use an existing rocket, such as the workhorse Atlas 5. In that scenario, Europa Clipper would launch in mid-2022 and, after a series of gravity assist flybys of Venus and Earth, would arrive at Jupiter in early 2030.

An alternative approach would use NASA’s still-in-development Space Launch System heavy-lift rocket to send Europa Clipper on a direct trajectory to Jupiter. A mid-2022 launch would allow the spacecraft to reach Jupiter in fewer than three years, without the need of any flybys.

Launching on SLS, Magner said, would reduce the costs of operating Europa Clipper given the much shorter travel time to Jupiter, and also simplify the thermal design since the spacecraft would not have to perform a Venus flyby in order to reach Jupiter. However, it was unclear how much more Europa Clipper would have to pay for an SLS launch.

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