# The Analysis of Experimental Deployment of IGLUNA 2019 Trans-Ice Longwave System
## 1 Introduction  
As the return of manned spacecraft to the Moon is predicted to take place as soon as the 2020s, new technology concepts and skilled human resources need to be created to support this process in a long-time perspective. One of the answers to these needs is the IGLUNA ESA_Lab demonstrator project, launched by the Swiss Space Center in 2018 and aimed at university students from European countries [1]. The 2019 (first) edition of IGLUNA took part in June 2019 in Zermatt, Switzerland, and comprised of two main venues: a mission to simulate a lunar habitat and surface operations on the Klein Matterhorn glacier and an exposition of conceptual designs of future lunar equipment in Zermatt's downtown. Among the student teams involved in the mission part of the initiative, the team P14 from Warsaw University of Technology, Poland, designed equipment responsible for providing radio communication on the surface of the glacier-for the 'astronauts' during simulated extra-evidivities--EVAs--and through the glacier into the simulated lunar habitat [2]. The surface radio communication system consisted of a 2.4-GHz network with mobile transceiver mounted on the astronaut's vambrace-it allowed the transmission of simple commands and telemetry data. The trans-ice communication system, connecting the EVA region with the habitat located 15 m below, inside the Glacier Paradise ice caves, consisted of two large antennas with separate transmitters and mobile receivers, forming a communication channel with the carrier frequency of 270 kHz (see schematic on Figure 1). As the designed channel was to overcome the main obstacle of the ice ceiling of the Glacier Palace, the preferred transmitting antenna type was determined as the magnetic loop--similar to the antennas of in-body implants, which allow the signal crossing of the tissue (highly humid, aqueous barrier) by employing the less-attenuated magnetic compound of the EM field created by two coaxially-placed loop radiators, functioning simultaneously as transmitting- and receiving ends [3], or antennas used for sub-surface communication systems for various data transmission--the majority of such systems used in deep caves [4] or mines [5], also employing magnetic antennas andLF/VLF frequency ranges for monitoring and rescue services (speelologists and miners). A large project also incorporating a loop antenna employing large terrain features was carried out in New Zealand in 1993 [6], yet with vertical polarization (VML--vertical magnetic loop), different frequency range and different (fully rocky) environment. Antennas deployed in the aforementioned cases were, however, used mainly in deep underground environments, with coal or solid rocks as surroundings--in the IGLUNA 2019 case, the surroundings were relatively thin (much shorter than the wavelength), icy, and positioned highly above the surface of the Earth. Nevertheless, the prevailing arguments for the HML (horizontal magnetic loop) antenna solution for IGLUNA 2019 were the character of the Glacier Palace (resembling a cave/tunnel from purely practical perspective) and the facility of installation (a ground-laid loop does not require high and elaborated supporting structures, which could pose a risk of corona discharges or stability issues on the surface of the glacier during blizzards) with simultaneous maximization of antenna length/aperture (using available floor/surface space) with minimum obstruction to the visitors of the Glacier Palace (as it was all publicly accessible throughout the field campaign). Initially designed as a combination of two D-class 1-kW transmitters, during the development phase of the project the system was changed to two A-class 1-W transmitters to comply with the imposed demand of functionality of an 'inductive device'--the requirement had to be met by a drastic reduction of power [7].