2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/209699We show that among simply connected surfaces of general type unirationality is a common feature, even when fixing the positive characteristic or numerical invariants. To do so, we construct unirational Horikawa surfaces in abundance.12 pages, 1 table; final version: corrected some typos, added details concerning Theorem 8, rephrased section 6Algebraic GeometryNumber Theory14J29, 14M20text