Antenna Technology Readiness for the Black Hole Explorer (BHEX) Mission

Abstract

The Black Hole Explorer (BHEX) will be the first sub-mm wavelength Space Very-Long-Baseline Interferometry (VLBI) mission. It targets astronomical imaging with the highest ever spatial resolution to enable detection of the predicted photon ring image feature of a supermassive black hole. BHEX is being proposed for launch in 2031 as a NASA Small Explorers mission. The BHEX science goals and the mission opportunity require a large, high precision, lightweight, spaceborne antenna. We present a survey of the technology landscape for realizing such an antenna. Technology readiness (TRL) for the antenna is discussed and assessed to be at TRL 5. A description of our technology maturation efforts towards TRL 6 is provided. Design studies leading to the preliminary design of a high efficiency antenna based on metallized carbon fiber reinforced polymer (CFRP) technology with a large 3.4 m primary reflector, a surface precision of < 40 μm to allow efficient operation up to 320 GHz, and a mass of only ~ 50 kg are outlined. Current plans anticipate attaining TRL 6 in 2027-28. Completed studies leading to the preliminary design point to a large margin in surface precision which also opens up applications at significantly higher THz frequencies, beyond BHEX.

arXiv comment4 pages, 3 figures, 2 Tables; updated version of v1 which was accepted at Proc. Int. Conf. Electromagn. Adv. Appl. (ICEAA), Palermo, Italy, Sep. 2025, but not presented as the author could not travel. This updated version was presented at URSI GASS 2026, Krakow, Poland, 15-22 August 2026