Speaker
Description
Over the past decades, ground-based astronomy has advanced through the search for drier sites and the construction of ever-larger telescopes, resulting in facilities such as VLT, ALMA, and soon the SKA and ELT. These observatories deliver unprecedented angular resolution and sensitivity, yet their cost and complexity continue to rise. At the same time, even prime observing sites such as the Atacama desert are experiencing worsening atmospheric conditions, underscoring the need to move the frontier of high-resolution astronomy into space.
Interferometry offers the only path to angular resolutions far beyond the capabilities of single-dish telescopes. Past space VLBI missions such as VSOP and RadioAstron demonstrated the feasibility of placing a radio antenna in orbit, but with only one spacecraft, their imaging capabilities and sensitivity were limited. Truly transformative progress requires an array in space: a constellation of antennas forming a flexible interferometer that can probe compact sources with unprecedented fidelity.
We present two complementary initiatives toward this goal. SHARP (Space-based High-resolution Array for Radio astronomy and Physics) is a concept submitted to the recent ESA call for M-class mission proposals. It will consist of three satellites operating at sub-mm wavelengths to demonstrate key technologies for space interferometry, including high-frequency receivers, precise baseline knowledge through GNSS and laser ranging, high-bandwidth inter-satellite links, and real-time correlation. SHARP will enable pioneering science such as resolving the event-horizon-scale structure of black holes at frequencies beyond the EHT.
Looking further ahead, Space Array is a study for a large orbital interferometric array of (sub-)millimetre and far-infrared antennas. Building on SHARP’s pathfinding work, Space Array envisions tens of satellites in medium Earth orbit, providing dense uv-coverage and order-of-magnitude improvements in angular resolution and imaging capability. Enabled by recent advances in small satellite platforms, re-usable launch vehicles, and precision metrology, such a facility would open a new era of ultra-high-resolution astronomy.
We will present the status on both initiatives and argue that the convergence of science drivers and technological maturity makes now the right moment to take decisive steps toward interferometric arrays in space.
