Description: Creating a ground penetrating radar (GPR) antenna for both Earth and planetary science applications requires high efficiency, robust operational frequency, as well as low size, weight, and power (SWaP) features. Furthermore, the value of an antenna that provides these core competencies and that is versatile enough to be integrated on numerous platforms is of high value to NASA and the commercial space industry. The benefits of such technology could enable the characterization of lunar lava tubes, subsurface water-ice, and the location of planetary ore deposits in a manner that is both affordable and simple to integrate with larger systems. The challenge is that this solution does not currently exist in the market. Choosing a solution that meets these criteria often requires combining multiple antennas, thereby increasing SWaP and complexity. The proposed antenna solution intends to resolve this challenge, and the proposing team of Astrobotic Technology, Inc. (Astrobotic) and the Ohio State University (OSU) have the expertise and technological development to do so. The performance and operational requirements of the proposed antenna are summarized as follows: Extremely wide operating frequency range from 120 MHz to 2000 MHz (bandwidth of 16:1) Effective ground coupling from a clearance of 8 cm – 20 cm Very low profile for ease of mounting under a mobile platform Low antenna ringing with good radiation efficiency Ground-independent antenna impedance matching condition Low sidelobe and backlobe above ground to minimize impacts from mounting different platforms Compact size (less than 75 cm (L) × 26 cm (W) × 7 cm (H) Simple lightweight structure (~300g) Space qualified in accordance with the thermal vacuum, shock, and vibration mission environments

Benefits: The success of the Phase I research will lead to a novel under-rover ultra-wide band GPR antenna design. Manufacturability will be assessed and real performance will be validated during Phase II and will culminate with an engineering model of the antenna that can be easily infused into future missions through the Commercial Lunar Payload Services (CLPS) program, Tipping Point program, or a Phase III opportunity that leverages any of Astrobotic's exiting Phase I or Phase II related contracts.

In addition to surveying planetary subsurfaces, there are numerous applications that demand mobile GPR. These applications include construction, land surveying, mapping building integrity, characterizing hazardous waste leakage, and identifying archeological artifacts. Furthermore, Astrobotic would be a user of this antenna for future rovers that require GPR capabilities.