Late Thursday NASA mission managers in Houston decided that Saturday’s spacewalk will not include repairs of Space Shuttle Endeavour’s heat shield.

"After hours of reviewing data and imagery collected during the inspections by the (shuttle) crew, the managers decided the damage did not pose a safety risk to the crew or Endeavour," a NASA statement said.

The Saturday’s spacewalk will proceed as planned but astronauts are to install and remove antennas on the outside of the ISS and conduct other construction projects.

NASA officials already extended the ongoing of the US space shuttle Endeavour at the orbiting International Space Station (ISS) with three more days. Under the new schedule, Endeavour is to decouple from the space station on August 20 and to land on August 22.

Initially, Endeavour’s mission was intended to last 11 days, but NASA announced the possibility to add three more days because the Station-to-Shuttle Power Transfer System allows the Endeavour crew to conserve the shuttle's battery power. The shuttled docked on August 10 with the International Space Station.

"The MMT made two significant decisions tonight," the chairman of the mission management team, John Shannon said. "The first was a unanimous recommendation that the damage we saw after reviewing all the engineering tests and analysis was not a threat to crew safety, this was not something that the astronauts are in danger about. We had thought that for several days, but we were waiting for the final analysis to be complete.”

The damage is not enough to risk a catastrophic failure of the shuttle's heat shield, like the one that destroyed the shuttle Columbia on re-entry in February 2002, but the process of underside repairs during a spacewalk would have entailed risks for the astronauts.

"We went through all of that data and it was unanimous that we were not in a loss of crew/vehicle case," Shannon said. "The discussion then centered on whether we should use as is and return Endeavour in its current condition or if the uncertainties in the analysis could potentially cause some underlying tile damage or structural damage that we would have to deal with at the Kennedy Space Center. So we had that debate. And it was not unanimous, but it was pretty overwhelming to go with the use-as-is condition, in other words not to do the tile repair."

Early on Thursday, Mission Specialists Barbara Morgan and Alvin Drew participated in an education event with students at the Challenger Center for Space Science Education in Alexandria, Va. Morgan.

The moderator was June Scobee Rodgers, the widow of Challenger's commander and the founding chairman of the Challenger center's board.

Barbara Morgan was awarded Wednesday with Center's Highest Honor, Challenger Center's President George H.W. Bush Award, for her 20-year commitment to keeping the spirit of education as an integral part of the NASA space program.

Barbara Morgan’ association with NASA began more than 20 years ago. Initially Morgan was selected as the backup candidate for the NASA Teacher in Space Program on July 19, 1985.

From September 1985 to January 1986, Morgan trained with Christa McAuliffe and the Challenger crew at NASA’s Johnson Space Center, Houston, Texas. After the Challenger accident Morgan resumed her career as teacher, but she was selected by NASA as a mission specialist in January 1998.

During the teaching session Morgan responded to questions such as what is her favorite space food (M&M she answered), if she can see constellations in space and how and where she sleeps during her space travel.

Morgan and Drew also talked with reporters representing Associated Press Television, Reuters and Idaho Public Television.