Harold Gehman, chairman of Columbia Accident Investigation Board (CAIB), said NASA has to "initiate an aggressive" program to ensure that foam or debris does not fall off in future shuttle launches.

The government troubleshooter also said the protective skin of the remaining space shuttles should be toughened so they can withstand impacts with minor pieces of debris during launch.

Despite these concerns, Gehman, a retired admiral, told a press conference, that:"The space shuttle program is not inherently unsafe."

He spoke after the released its findings into the Feb 1 Columbia shuttle disaster which claimed the lives of seven astronauts, including the first Israeli in space.

The report confirmed that a piece of foam broke off the shuttle's launch structure during take off, pierced the craft's skin and sparked the eventual overheating the tore Columbia apart as it re-entered earth's atmosphere February 1.

John Logsdon, a director of the Space Policy Institute, who sat on the 13-strong board with Gehman said NASA's "culture must be modified."

The board said they were concerned that NASA's culture contributed to the disaster as internal concerns raised during the Columbia mission were ignored.

Major General John Barry, another CAIB member and former fighter pilot, also said a "broken safety culture resides in the human space flight" program.

Gehman said the board had delivered a hard-hitting report because it did not want its safety warnings to be forgotten in a few years.

While levelling equal criticism at National Aeronautics and Space Administration managers as at the foam shard that hit Columbia, Gehman said NASA's launch schedules should be more flexible if concerns mount prior to launch.

Logsdon noted that "the shuttle program was squeezed during the 1990s."

He said NASA's budget and staffing levels were cut by 40 percent during this period.

The report was delivered to the White House, Congress and the families of victims simultaneously today.

SPACE.WIRE