ORLANDO, Fla. (AP) -- There are no major hurdles to NASA launching a space shuttle in May or June, a task force overseeing return-to-flight efforts said, while also expressing concern about crew members' ability to make repairs in orbit.

"There are no show-stoppers that we see out there," Richard Covey, co-chairman of the Return to Flight Task Group, said Friday.

Covey said one issue that may arise is the availablility of "feasible repair techniques."

NASA has scheduled a May or June launch window for Discovery, which would be the first shuttle sent aloft since the Columbia's breakup over Texas two years ago that killed seven astronauts. A chunk of foam insulation from Columbia's fuel tank had come off during launch and ripped a hole in the left wing, dooming the shuttle.

Discovery's seven astronauts will have a hole-repair kit, although it is uncertified and rudimentary. If unable to return to Earth, they also would have the option of moving into the orbiting space station to await rescue by shuttle Atlantis in a month's time.

NASA still needs to fulfill eight of 15 recommendations made by the Columbia accident investigators, Friday's report said. Unfinished items include preventing the shedding of debris and hardening the orbiter.

But NASA is close to completing several of those recommendations and should be able to complete them before the launch window, Covey said.

The task force - headed by Covey, a former shuttle commander, and former Apollo astronaut Thomas Stafford - is charged with evaluating how NASA is implementing the recommendations made by the Columbia Accident Investigation Board. Members plan to issue a final report in April.