Another space shuttle disaster could occur if Nasa does not address its self-protective culture, which is schedule-driven, hampered by lack of funds and burdened by an insufficient safety programme, investigators of the destruction of the space shuttle Columbia said yesterday.

The investigation board's scathing report into February's tragedy, which killed seven astronauts, said little had changed at Nasa since the 1986 Challenger crash. Its report said: "The board strongly believes that if these persistent, systemic flaws are not resolved the scene is set for another accident."

In the run-up to the loss of Columbia, Nasa mission managers routinely accepted as normal some flaws in the shuttle system, including the breaking away of foam insulation, which fatally damaged Columbia's heat shield.

The investigators made 29 recommendations, including some that the agency must act on before it launches another flight. Some blame was also shifted to Congress and the White House, because Nasa lost 13% of its purchasing power between 1993 and 2002.