The next Space Shuttle mission is unlikely before spring of next year, says shuttle director Michael Kostelnik.
Work continues on the space vehicle which has not flown since the shuttle Colombia was destroyed on re-entry from orbit a year ago. It had been hoped that the work would be completed by September, with shuttle Atlantis resuming missions to the International Space Station.
New rules will limit the launch of the shuttle to daylight hours when it can be observed during flight - one of the recommendations in a report following last year's disaster.
Kostelnik said the biggest problem was finding ways to make sure the foam insulation on the shuttle's external fuel tank did not fall off during launch.
It was a section of foam that fell off Columbia's tank while it was launched last year striking the left wing that ultimately caused the accident.
Nasa was unaware of the extent of the damage until the shuttle was destroyed during its return to Earth 16 days later, killing the seven crew members.
Nasa has pledged to implement all the recommendations of the investigation board.
Source: Flight Daily News
