BEIJING, Aug. 27 (Xinhuanet) -- A new X-ray analysis reveals small cracks in the insulating foam over the brackets of space shuttle Discovery's external fuel tank and NASA has called for its removal before the spacecraft can fly again, the agency said Friday.

NASA engineers said the foam -- called Super Light-weight Ablative, or SLA -- should be removed from the brackets because the cracks make the material prone to shedding.

The work will take about nine days and is not expected to delay Discovery's next launch, scheduled for Oct. 23.

Insulating foam covers a shuttle's external tank to prevent ice from building up when super-cold liquid oxygen and hydrogen fuel is pumped into it in the hours before launch.

But foam shedding has been a huge problem for NASA in recent years. The agency has been extremely watchful for any damage to the tank or heat shield after the 2003 Columbia disaster caused by foam shedding.

Two-and-a-half years later, on the first post-Columbia flight, a briefcase-size piece of foam flew off Discovery's tank, narrowly missing the orbiter. The fleet was grounded for another year while engineers designed a fix for that problem.

And just this month, a piece of SLA foam fell off Endeavour's fuel tank 58 seconds after that shuttle's lift-off on Aug.t 8, bounced off a strut connecting the shuttle to the tank, and gouged the sensitive heat-resistant tiles on the underside of the orbiter.

Next year NASA will debut a tank redesign featuring titanium brackets that will not need to be coated with foam at all.

(Agencies)