RIMFAX

RIMFAX
Name	RIMFAX
Country	Norway
Operator	Norwegian Space Agency
Manufacturer	Norwegian Defence Research Establishment
Spacecraft	Perseverance (rover)
Launch	Mars 2020
Mission	Mars 2020
Type	Ground-penetrating radar

RIMFAX is a ground-penetrating radar instrument aboard the Perseverance (rover) of the Mars 2020 mission. Developed by the Norwegian Defence Research Establishment and managed by the Norwegian Space Agency, it provides high-resolution subsurface imaging to depths of several meters, complementing instruments such as Mastcam-Z, SHERLOC, SuperCam, and PIXL. RIMFAX supports objectives tied to Mars Sample Return, geological context, and astrobiology investigations aligned with NASA and international partners like the European Space Agency.

Overview

RIMFAX is a radar sounder designed to probe Martian near-surface stratigraphy and structure, operating in concert with the Perseverance (rover) payload including MOXIE, MEDA, Ingenuity (helicopter), Sherlock Holmes? (note: exclude incorrect items). Its primary role links to mapping sedimentary layering, detecting buried channels, and identifying subsurface materials significant for Mars Sample Return planning and site characterization, interfacing with teams from Jet Propulsion Laboratory, Caltech, Ames Research Center, and the Smithsonian Institution.

Design and Instrumentation

The instrument hardware was built by the Norwegian Defence Research Establishment with contributions from academic partners such as University of Oslo, Norsk Romsenter, and industrial contractors collaborating with Lockheed Martin and SpaceX supply chains indirectly through NASA procurement. RIMFAX comprises a broadband antenna, transmitter, receiver, and on-board signal-processing electronics mounted under the rover chassis near the Curiosity (rover)-class mobility system. The design draws on heritage from terrestrial ground-penetrating radars used by organizations including Norwegian Geological Survey and techniques developed at Stanford University and Massachusetts Institute of Technology laboratories. Power, thermal, and data interfaces conform to NASA Deep Space Network and JPL system architectures.

Science Objectives and Methods

RIMFAX aims to (1) image subsurface stratigraphy to inform selection of samples for Mars Sample Return, (2) detect buried structures such as paleochannels and impact-related layering tied to missions like Mars Reconnaissance Orbiter investigations, (3) search for near-surface ice and layering relevant to astrobiology hypotheses and Planetary protection planning, and (4) provide context for surface observations from instruments like Mastcam-Z and PIXL. Methods include multi-frequency chirp transmissions, multi-offset acquisition, and synthetic-aperture processing informed by algorithms developed at Norwegian University of Science and Technology and University of California, Los Angeles. Comparative integration uses datasets from orbital instruments such as SHARAD, MARSIS, and imaging from HiRISE.

Data Acquisition and Processing

RIMFAX collects raw radargrams during rover traverses, synchronized with rover localization from Navcam, Hazcam, and the guidance, navigation, and control system managed by JPL. Data are downlinked via Mars Relay Network assets including Mars Reconnaissance Orbiter, MAVEN, and Trace Gas Orbiter when available. Onboard preprocessing performs filtering, time-zero correction, and dynamic range adjustments before storage in the rover science data system integrated with Viking-era heritage protocols updated by JPL engineers. Ground processing pipelines apply migration, deconvolution, and velocity estimation using laboratory-derived dielectric models from research at University of Oslo, Brown University, and ETH Zurich to convert two-way travel times into depth estimates and to discriminate lithologies.

Results and Discoveries

RIMFAX returned layered subsurface profiles revealing stratigraphic sequences consistent with fluvial, deltaic, and aeolian depositional environments interpreted alongside Mastcam-Z imagery and SuperCam compositional data. Analyses identified sedimentary layering, clast-rich horizons, and dielectric contrasts indicative of potential buried ice or cementation, helping to contextualize samples targeted for Mars Sample Return. Correlative studies compared RIMFAX profiles with orbital sounding from SHARAD and high-resolution imaging from HiRISE and CTX, refining models of local sediment thickness and depositional history relevant to regional studies by teams at Caltech, Brown University, and University of Arizona. Novel features reported include small-scale subsurface reflectors suggesting buried channels and structural discontinuities that informed rover traverse planning and sampling strategies.

Operations and Mission Context

RIMFAX operations are coordinated through science leads at the Norwegian Space Agency and instrument teams collaborating with Jet Propulsion Laboratory, Caltech, and NASA mission management. Tactical planning integrates RIMFAX acquisitions into daily rover command cycles alongside instruments like PIXL and SHERLOC, balancing power and data-volume constraints negotiated with Mission Control Center schedules. RIMFAX also supports preparations for Mars Sample Return by providing subsurface context for caching decisions, and results feed into broader comparative planetology work involving researchers from Smithsonian Institution, European Space Agency, NASA Ames Research Center, and universities worldwide. Continued operations depend on rover longevity, funding allocations from agencies such as the Norwegian Space Agency and NASA, and coordination with future sample return campaign milestones.

Category:Instruments aboard Perseverance