WASHINGTON --The Stafford-Covey Return to Flight Task Group announced Wednesday that it has closed out all but three of the 15 recommendations NASA must complete before it can launch the Space Shuttle Discovery in July.

The group plans to meet again toward the end of June, either face-to-face or via teleconference, to close out the remaining items related to tank debris, orbiter hardening and tile repair.

The task force group, led by veteran astronauts Thomas Stafford and Richard Covey, was established in the wake of the February 2003 Space Shuttle Columbia accident to monitor NASA's compliance with the recommendations of the Columbia Accident Investigation Board (CAIB). The CAIB released 29 findings and recommendations for NASA, 15 of which needed to be addressed before returning the shuttle fleet to flight status.

Covey told reporters in Houston Tuesday that the task group has closed out five additional recommendations since its last meeting. Those items had mainly to do with management issues and steps NASA has taken to more closely observe the shuttle during its launch and ascent.

Among the three remaining recommendations that Stafford-Covey must still close out, Covey and other members of the task group said they saw no show-stoppers that should interfere with return to flight.

Covey said the task group has additional analysis to do on changes NASA has made to prevent the shuttle's external tank from shedding potentially lethal debris such as insulating foam and ice during launch. The group must also perform additional analysis to evaluate changes NASA has made to harden the shuttle orbiter against debris damage and determine whether the fixes were sufficient to comply with the CAIB recommendations. Covey said the group has nearly all the data in hand it needs to reach a judgment and expects to be able to do so in time for a flight readiness review NASA has tentatively scheduled for June 29 and 30.

The only other remaining open item relates to orbiter inspection and repair. The CAIB said NASA must have a "practicable" solution for repairing "the widest possible range of damage". The ambiguity of the wording recommendation has been a source of ongoing debate among Stafford-Covey task group members. Jim Adamson, chairman of the group's operations panel, said until that debate is resolved the group will not be able to determine whether or not NASA is in full compliance with that particular CAIB recommendation.

Either way, NASA has made clear it intends to resume shuttle flights with the repair capabilities it has in hand without knowing for sure whether they would work in an emergency.

At present, Discovery is being fitted with a new external tank, and the spaceship should be back at the launch pad within a week. Concerns over the potential danger of ice debris from the original external tank led mission managers to call for the refit, drawing out the shuttle's launch to no earlier than July 13.