The space shuttle Discovery has been cleared for re-entry to earth next week.
NASA officials told astronauts on the shuttle that its heat shield is safe after concerns that it had been damaged during lift-off.
Engineers at mission control in Texas said it was not necessary to have an astronaut conduct a space walk to make minor repairs to the shield.
In 2003, space shuttle Columbia broke up on re-entry after lift-off debris pierced its heat shield.
Discovery is just the second shuttle flight since that disaster, in which all seven crew members died.
