The MegaWave Radio Surveyor

The MegaWave Radio Surveyor is an ASTRA Initiative concept for a space-based interferometer designed to open the largely-unexplored low-frequency radio window, below roughly 45 MHz, which is inaccessible from Earth. It addresses Decadal-level questions across astrophysics, exoplanets, astrobiology, and cosmology, and is responsive to the Pathways to Discovery Decadal Survey, three other National Academies studies, and the Enduring Quests, Daring Visions roadmap.

The observatory would use an architecture that is versatile, scalable, and resilient, enabling sensitive and simultaneous observations below 45 MHz with unprecedented angular resolution. It builds on NASA's SunRISE, SPARCS, and LuSEE-Night, and could leverage Artemis program capabilities such as access to and beyond cislunar space, communications, and new autonomy/AI modes for operations.

Its four core science goals are to track space weather of other stars; detect magnetically-generated emission from exoplanets to probe their interiors and assess magnetic shielding of their atmospheres; probe the Universe's evolution during the Dark Ages via the highly-redshifted HI hyperfine line; and assess the role of cosmic rays and magnetic fields in the cosmic web.

By opening one of the last windows in the electromagnetic spectrum and pioneering space interferometry at unprecedented scales, the MegaWave Radio Surveyor would establish a transformational capability, made feasible by recent developments in U.S. space industries.