MACIE: Mars Astrobiology Cave and Internal habitability Explorer
A New Frontiers Mission Concept
Shown here: The inside of a lava tube at Craters of the Moon National Monument, Idaho. The floor is covered in ice. The inset is a scanning electron microscope image of the microorganisms living in this lava tube.
WHAT IS MACIE?
The Mars Astrobiological Cave and Internal habitability Explorer (MACIE) is named for Macie Roberts, one of NASA’s ‘human computers’. As a group chief for the computers at JPL and she provided job opportunities for women in space. It seems only fitting a mission concept designed to a hidden habitable environment would highlight these oft hidden contributions of women to space science and exploration.
MACIE would access the Martian subsurface via a lava tube. Lava tube caves are compelling subsurface astrobiological targets because they have their own relatively stable microclimates, are shielded from radiation and harsh surface conditions, and may contain water ice. Lava tube caves may also provide access to materials vital to future human exploration and in situ resource utilization (ISRU) activities (Sam et al., 2020).
A cave mission represents a compelling next-step in Mars astrobiology and habitability exploration. We expect to propose MACIE to the New Frontiers 7 call, late in the 2020s.
You can read our MACIE Concept Whitepaper submitted to the Decadal Survey LOCATED here.
We chatted with WeMartians Podcast about this (listen here) and we have a press release with Astrobiology Web.
Map of the Tharsis Region on Mars. Orange dots indicate the locations of lava tube caves that may host water ice (Williams et al. 2010). Ice caves are expected to exist across Mars surface in Noachian to Amazonian terranes; however the highest density of lava tube caves that may host ice are in the Tharsis region.
This is one potential mission architecture MACIE could adopt. Here we feature a legged rover being tested by the CoSTAR team, a comms relay that could be deployed within the lava tube and a landed asset that could communicate back to Earth.
MACIE’s MISSION GOALS:
Assess the present and past habitability of a martian lava tube
The Martian subsurface is expected to have remained habitable long-after surface conditions degraded.
search for evidence of present or past life
MACIE would target multiple objectives to determine whether life may have existed in a lava
tube now or in the past. These biosignatures would indicate whether life may have colonized a Martian cave and represent a major advance in our understanding of the astrobiological potential of Mars’ deep subsurface.
What’s next for MACIE?
To make MACIE feasible in the next decade, we need to narrow down potential landing sites. While many cave entrances on Mars are vertical entrances, which would require a tethered robot like MoonDiver’s Axel, some entrances are lateral, allowing a robot to walk into the cave.
While other mission ideas can select a landing location late in the development cycle, we need to prioritize this selection early in the process as it will drive engineering decisions and therefore, cost. Current work being done by scientists analyzing HiRISE and SHARAD data will help us make these choices.
Want to help?
Community enthusiasm and support for subsurface exploration to understand Mars’ habitability and astrobiological potential are essential. Your enthusiasm and engagement with the space program help drive our ability to understand our Solar System. Let’s keep the excitement up about all of the exploration going on, including Europa Clipper, DragonFly, Mars2020, ExoMars, and other planetary missions that help us learn more about our place in the Universe.
We face several challenges that must be solved to propose MACIE. Because MACIE would potentially employ a novel space craft architecture and explore an unknown place where communication will be limited, more work needs to be done to support machine learning and artificial intelligence. MACIE will likely require autonomous sampling, on-board data processing and prioritization, and autonomous navigation. Continuing support for this type of science research will help MACIE’s development. Supporting basic scientific research to better connect lava tube skylights to their subsurface extents, e.g. the ongoing SHARAD work, is essential as it will help us further constrain the best sites for MACIE to potentially explore. This will drive the engineering developments. Additional developments, like a commercial-public partnership for Mars exploration may help lower mission costs. If the Lunar commercial-public partnerships go well, this may set the stage for MACIE.