Preparing for subsurface planetary exploration


DEPTHX. Credit:

In October 2018, a study committee of the National Academies of Science, Engineering, and Medicine (NAS) – specifically, the Committee on the Astrobiology Science Strategy for the Search for Life in the Universe, Space Studies Board –  published a reportproviding recommendations for a NASA astrobiology strategy for the search for life in the universe. IMHO, the report is on the mark. (Whether the White House and Congress will provide needed funding to enable the implementation of these recommendations remains to be seen.)

I am a (part-time) consultant to the NASA astrobiology program and was asked to help prepare a NASA response to the NAS committee’s recommendations. Much of the content I prepared was deleted. But it’s still interesting. So I’ll provide it here.

One of the NAS study committee’s recommendations was that “NASA’s programs and missions should reflect a dedicated focus on research and exploration of subsurface habitability in light of recent advancesdemonstrating the breadth and diversity of life in Earth’s subsurface, the history and nature of subsurface fluids on Mars, and potential habitats for life on ocean worlds.”

Exploring for evidence of subsurface habitability in the solar system is a big deal in planetary science these days. Astrobiologists are itching to get beneath the surface of Mars, Europa, and Enceladus (I should note that such missions are only ideas at this point…but good ideas, IMHO).

The work on this goal that the NASA astrobiology program has funded over the past 10-15 years (and continues to fund today) is fascinating (at least to this space science geek). And it shows how slowly, but methodically, the development of planetary exploration technologies proceeds, step by step.

Over the past several years NASA has taken some steps to advance research and exploration of subsurface habitability by funding a number of projects to develop and demonstrate subsurface exploration technologies and techniques. NASA’s Planetary Science and Technology Through Analog Research (PSTAR) Program has funded the Atacama Rover Astrobiology Drilling Studies (ARADS) project, led by Brian Glass of NASA Ames Research Center. The ARADS project, intended to iteratively develop a simulated Mars rover mission, conducted its first field test in Chile’s Atacama Desert in 2016. Several instruments have been designed, developed or modified to be tested in ARADS field experiments, including the fifth generation of a series of space-prototype, one- to two-meter-class rotary-percussive drills by Honeybee Robotics; a sample-transfer robotic arm from MDA Aerospace (the developer of robotic arms for NASA’s Phoenix and InSight missions to Mars); and a new autonomous mid-sized rover concept (K- REX2) developed by NASA Ames.

NASA also has funded the Mars Analog Rio Tinto Experiment (MARTE), led by Carol Stoker of NASA Ames. The MARTE project is developing drilling, core- and sample-handling, and instrument technologies relevant to searching for life in the martian subsurface and demonstrating them in a Mars-analog site on Earth, Spain’s Rio Tinto region. The MARTE drilling system is being developed by Honeybee Robotics for future use on Mars. Honeybee Robotics has developed drilling and sample-handling systems for NASA’s last three Mars landers, including systems for the last three of NASA’s Mars landers, including the first drill ever to look inside a rock on Mars and the sample-handling system on the Mars Science Laboratory. (I visited Honeybee Robotics in New York City several years ago – those people produce amazing technology.)

NASA’sMars 2020 rover will feature a drill that can collect core samples of the most scientifically promising rocks and soils and cache them on the surface of Mars for future retrieval and return to Earth.The European Space Agency’s (ESA’s) ExoMars 2020 rover willcollect samples with a drill down to a depth of two meters and analyze them with next-generation instruments in an onboard laboratory. NASA and ESA are closely coordinating work on these two missions and will be sharing data from science operations.NASA is providing a major portion of the premier instrument for ESA’s ExoMars mission: the mass spectrometer for the Mars Organic Molecule Analyzer.  In addition, European scientists are on a number of instrument teams for NASA’s Mars 2020 mission.  In 2018,the NASA astrobiology program awarded a $7 million grant to a Georgia Institute of Technology-led Oceans Across Space and Time alliance to intensify the search for life in our solar system’s present and past oceans. This alliance is a member of the Network for Life Detection (N-FoLD), an astrobiology research coordination network (RCN) focusing on life detection strategies and methods.

The NASA astrobiology program has supported two recent “workshopswithout walls” (virtual workshops) that focused on research and exploration of subsurface habitability: “Upstairs Downstairs: Consequences of Internal Planet Evolution for the Habitability and Detectability of Life on Extrasolar Planets,” held February 17 – 19, 2016, in Tempe, Arizona, and virtually; and “Serpentinizing Systems Science,” held January 31, 2017, virtually. NASA Astrobiology is also co-hosting a conference, “Mars Extant Life: What’s Next?” January 29–February 1, 2019, at the National Cave and Karst Research Institute. This conference will focus on understanding and discussing strategies for exploring candidate target environments on Mars that may host evidence of extant life including surface, shallow subsurface, and deep subsurface niches.

Astrobiology is well represented on NASA’s Europa Clipper mission team. Europa Clipper (to launch some time in the 2020s) willconduct detailed reconnaissance of Jupiter’s moon Europa to see whether the icy body might be habitable. The science definition team for the Europa Lander mission concept study included several astrobiologists, including Alison Murray as one of the co-chairs and Ken Nealson, Chris German (Woods Hole Oceanographic Institute), Britney Schmidt (Georgia Institute of Technology), and Alexis Templeton (University of Colorado) as team members. (All three of these scientists have done fascinating astrobiology research in the field.) The SDT identified three science goals for the mission: detect and characterize biosignatures and signs of life, analyze in-situ habitability, and prepare for future exploration. The mission concept team identified a model payload for this mission that includes, among other instruments, a microscope for life detection and an organic compositional analyzer.

The technological challenges of exploring subsurface environments on icy worlds are formidable. On Earth, researchers have only reached a depth of 3.5 kilometers beneath ice. Europa’s ice shell could be as much as 15 kilometers deep. Consequently, the NASA astrobiology program has supported a number of technology development and demonstration projects for in-situ exploration of subsurface environments on other planetary bodies.

For example, the program has supported the development of four Stone Aerospace autonomous underwater vehicles (AUVs) that are prototypes for subsurface exploration of Europa: DEPTHX (Deep Phreatic Thermal Explorer), ENDURANCE (Environmentally Non-Disturbing Under-ice Robotic ANtarctiC Explorer), VALKYRIE (an ice-penetrating robot), and ARTEMIS (Autonomous Rovers/airborne-radar Transects of the Environment beneath the McMurdo Ice Shelf). (Bill Stone, founder and head of Stone Aerospace, is a brilliant engineer and obsessed with Europa.)

The NASA astrobiology program also funded the development oftwo underwater autonomous vehicles (AUVs) called Jaguar and Puma, developed by the Woods Hole Oceanographic Institution (WHOI) and deployed on WHOI’s 2007 Arctic Gakkel vents expedition (AGAVE). Jaguar and Puma are prototypes of AUVs that could look for evidence of subsurface hydrothermal activity on other planetary bodies. The NASA astrobiology program also funded the Monterey BayAquarium Research Institute’s development of another subsurface planetary exploration prototype, an Environmental Sample Processor for Deep-Sea Seep and Hydrothermal Vent Applications.

The Science Mission Directorate’s Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO), MATuration of Instruments for Solar System Exploration (MatISSE), and Planetary Science and Technology from Analog Research (PSTAR) R&A programs have also funded a number of projects aimed at aiding the exploration of subsurface planetary environments. For example, the PICASSO program has funded work on a rover-mounted dielectric (non-conducting) spectrometer for in-situ subsurface planetary exploration, which could measure subsurface material composition at radio frequencies; and a compact color “biofinder” for fast, non-contact detection of biomarkers, biomolecules and polyaromatic hydrocarbons in ocean worlds.

The MatISSE program has funded the development and testing of a prototype digital beam-forming polarimetric synthetic aperture radar (look it up) for subsurface imaging. This instrument could detect and map buried ice deposits and measure the depths of such deposits. The PSTAR program has funded the development and demonstration of a thermal high-voltage ocean-penetrator research platform, a cryobot (a robot that can operate in freezing temperatures) capable of rapid, deep subglacial access that carries an onboard science payload optimized for environmental characterization and life detection; a seismometer designed to investigate ice and ocean structure (SIIOS) on Europa and Enceladus; the SUBSEA project, which is exploring the habitability of a seamount (a mountain on the sea floor whose peak is well below the surface of the water) off the coast of the Big Island of Hawaii as an analog for icy moons, using two submarine-type remotely operated vehicles; and the DEEP project – Detecting Extraterrestrial Piezophiles in ocean-world analog environments – which is testing a high-pressure sampling system in deep hydrothermal vents in the mid-Cayman Rise that would allow sample retrieval and manipulation without decompression, enabling sample-handling protocols that optimize life detection in high-pressure environments. (A piezophile, also known as a barophile, is an organism that thrives in high-pressure environments.)

NASA’s publicity machine tends to focus on promoting missions. But those missions are made possible by projects such as those described here. It’s going to be a long, slow trip to exploring subsurface environments in the solar system. But the trip will be worth it, I think. Given NASA’s current obsession with sending people back to the Moon and on to Mars, I keep thinking that robotic planetary exploration has been what’s delivered the goods for decades.

Moon-Mars Madness, Redux



As Yogi Berra once said, “it’s like déjà vu all over again.”

Last week, the Vice President of the United States, who chairs the National Space Council, told NASA that the President is directing the agency to land people back on the Moon by 2024, “by any means necessary.”

Today, NASA Administrator Jim Bridenstine testified to the House Science, Space and Technology Committee – the committee in charge of authorizing NASA spending – about the administration’s $20 billion fiscal year 2020 budget request for NASA – which does not include funds for a return to the Moon by 2024.

In fact, the 2020 budget request calls for a return to the Moon by 2028.

Rep. Kendra Horn (D-OK), chair of the House Science, Space and Technology Subcommittee on Space and Aeronautics noted in her opening statement for today’s hearing, in September 2018, “a full year and a half AFTER its Congressionally-directed due date, the Committee received the report directed in Section 435 of the NASA Transition Authorization Act of 2017.”

According to Rep. Horn, this report – the NASA Exploration Campaign Report – “is a high-level strategy…mainly a plan for a plan…and may not ultimately play a substantive role in efforts to place humans in Mars orbit by 2033. Further specificity of NASA’s long-term plans in a public document would help Congress and other public policy officials make informed decisions over the coming decades.”

According to the Exploration Campaign Report, “The National Space Exploration Campaign strategy is ready. It includes direction from the White House and Congress, with input from industry, academia, international partners and, most importantly, the American public. It is not a repeat of efforts of the past 50 years. The National Space Exploration Campaign does not assume or require significant funding increases.”


Today, Bridenstine told the House committee that meeting the President’s 2024 goal would require a supplemental budget request.

According to the Exploration Campaign Report, “NASA is building a plan for Americans to orbit the Moon, starting in 2023, and land astronauts on the surface no later than the late 2020s…. By the late 2020s, a lunar lander capable of transporting crews and cargo will begin sortie missions to the surface of the Moon.”

Uh huh.

Those of us who have been working in the space community for some time (for me, since 1983), we’ve heard “bold” calls over and over again for a return to the Moon and human missions to Mars. I have a large stack of reports in my office on Moon-Mars proposals and plans.

In 1986, President Reagan received a report from a National Commission on Space (NCoS – which I worked for) outlining goals for the next 20 years of U.S. space exploration. NCoS offered a rationale for exploring and settling the solar system and a “vision” of making the solar system “the home of humanity.”  At the same time, NCoS noted, “financial realities will dictate the pace at which we proceed.”

By 2006, we had not proceeded very far along the way to executing the NCoS vision.

In 1989, President George H.W. Bush directed NASA to develop what became the Space Exploration Initiative (SEI), which would send people back to the Moon and on to Mars. According to NASA’s “Report of the 90-Day Study on Human Exploration of the Moon and Mars” (November 1989), “The basic mission sequence is clear”: first build a space station, then “return to the Moon to stay early in the next century, and then journey to Mars” by 2019.

In 1991, a “Synthesis Group” tasked with reporting on the Space Exploration Initiative produced four possible architectures for the SEI.

Funding did not materialize.

In 2004, President George W. Bush announced his “Vision for Space Exploration”, directing NASA to develop a Crew Exploration Vehicle by 2008 “and to conduct the first [crewed] mission no later than 2014. The Crew Exploration Vehicle will be capable of ferrying astronauts and scientists to the Space Station after the shuttle is retired. But the main purpose of this spacecraft will be to carry astronauts beyond our orbit to other worlds…. Beginning no later than 2008, we will send a series of robotic missions to the lunar surface to research and prepare for future human exploration. Using the Crew Exploration Vehicle, we will undertake extended human missions to the moon as early as 2015, with the goal of living and working there for increasingly extended periods.”

And…here we are.

In her opening statement for this morning’s hearing with Bridenstine, Science, Space, and Technology Committee chair Eddie Bernice Johnson (D-TX) got right to the point:

“You have stated that NASA’s fiscal year 2020 budget request is a good one, apparently in part because the President didn’t cut your budget as much as he is proposing to cut the rest of America’s federal R&D investments, including misguided and harmful cuts to DOE’s and NSF’s research budgets. I am not persuaded. In fact, I find both this NASA budget request and your written testimony for today’s hearing to be disappointing and inadequate.”

Rep. Johnson indicated that the budget request as it stands will likely not make it through Congress. “The President’s budget request for FY 2020 proposes the same ill-advised cuts to important NASA science and education initiatives that it did last year—cuts which Congress has already considered and rejected in the FY 2019 appropriations act.” She and other members of the committee criticized proposals to de-fund key NASA STEM activities—especially those that support students – the WFIRST mission – “the highest ranked astrophysics decadal priority” and “two critical Earth Science missions.” These cuts “made no sense last year,” Rep. Johnson said, “and they make no sense this year. I have little doubt that those cuts will be rejected by Congress once again.”

“And what is the justification for this crash program?” Johnson went on. “To quote the Vice President again, it’s because ‘we’re in a space race today, just as we were in the 1960s, and the stakes are even higher.’ Moreover, according to the Vice President, the Chinese have ‘revealed their ambition to seize the lunar strategic high ground,’ whatever that means. The simple truth is that we are not in a space race to get to the Moon. We won that race a half-century ago, as this year’s commemoration of Apollo 11 makes clear. And using outdated Cold War rhetoric about an adversary seizing the lunar strategic high ground only begs the question of why if that is the Vice President’s fear, the Department of Defense with its more than $700 billion budget request, doesn’t seem to share that fear and isn’t tasked with preventing it from coming to pass…. Given the absence of an urgent crisis, it would be the height of irresponsibility for the Vice President of the United States to direct NASA to land astronauts on the Moon within the next five years without knowing what it will cost, how achievable the schedule is, and how it will impact NASA’s other programs.”

I heartily agree with Rep. Johnson.

Rep. Horn had this to say in her statement:

“Let’s take a moment to review the last three to four months. First, the Administration shut down the Federal Government for a total of 35 days…. [M]any projects will experience delays and some level of cost increase due to the disruption.  Second, in a delayed release of the FY 2020 budget request due to the shutdown, the Administration proposed a more ambitious Moon program– to send humans to the lunar surface by 2028 — while also proposing to cut a half billion dollars from the agency’s topline relative to the FY 2019 enacted appropriation. Third, just two weeks AFTER the Administration released its FY 2020 request for NASA, the Vice President announced that ‘it is the stated policy of this administration and the United States of America to return American astronauts to the Moon within the next five years’….Fourth, last Friday, again just weeks AFTER releasing the FY 2020 Request, the Committee received notice of NASA’s request for a major reorganization of NASA’s technology and exploration activities that NASA is proposing through a ‘reprogramming request’ to the Committee on Appropriations.”

(Are you confused? I am.)

Horn went on, “This request would create a new Moon to Mars Mission Directorate that would subsume the space technology program into a Directorate focused on large exploration development programs like the Gateway. NASA’s request proposes other major organizational changes that, if approved, would bypass this Committee’s authorizing role in considering such drastic reorganizational changes.”

“These issues are not partisan,” she said. “We have learned over several Congresses and Administrations that attempting to implement major programs through fits and starts creates confusion and often delays progress. Changes in direction also present challenges for the Committee’s work toward providing effective guidance and policy through the reauthorization process.”

She is right on.

Finally, I will note that a recent poll by a reputable organization, the Pew Research Center, showed that respondents ranked returning people to the Moon and sending people to Mars #8 and #9 – next to last and last – on a list of nine priorities for NASA.

Perhaps the worst aspect of these stop-and-start plans is that so many people work diligently on them, only to see them shelved. NASA wastes hundreds of millions of dollars on studies mandated by the White House and Congress for projects and programs that don’t receive adequate funding. (I wonder if we’ll ever know how much money NASA invested in the now-defunct Asteroid Initiative.) It’s too bad.