NASA's independent investigative arm has called for the suspension of 6 of the 19 members of a board charged with reviewing the agency's programme to replace the space shuttle.

The board members in question are employed by contractors already working on Orion, the shuttle's replacement. This creates a conflict of interest that violates US federal law, the Office of the Inspector General said in a report issued last week.

But NASA officials have said that the board should remain intact and that it is difficult to find completely independent aerospace experts. The inspector-general's office is calling that “nonresponsive”. Further action may be taken after 28 May, when NASA's comments on the report are due.