Before the first stars lit the universe, hydrogen filled the cosmos in silence — and the faint radio echo of that primordial darkness has never been heard from Earth. A team of international researchers now proposes CosmoCube, a suitcase-sized spacecraft that would orbit the Moon's far side, using the lunar body itself as a shield against the electromagnetic noise of human civilization. The mission seeks to capture the 21-centimetre hydrogen signal — a whisper from the universe's first billion years — and in doing so, illuminate how dark matter, gas, and gravity conspired to birth the first ga