Nasa said tonight it would not try to launch the space shuttle Discovery until late next week – at the earliest.

A former Nasa inspector has been accused of lying about inspecting crucial parts on the space shuttle Discovery before and after the Columbia disaster that killed seven astronauts and grounded the entire orbiter fleet.

Nasa has discovered a fuel-line crack in its newest space shuttle today, the same potentially dangerous problem affecting the rest of the fleet.

Nasa will give only 24 hours notice of its exact launch times from now on to guard against possible terror attacks.