NASA: Extra Heat Shield Inspection Unlikely for Shuttle Discovery

HOUSTON – Astronauts aboard the space shuttle Discovery will likely not have to perform a focused inspection of their spacecraft’s heat shield, NASA said Thursday.

NASA shuttle engineers poring over recent data and images of Discovery’s heat shield have yet to find concerns that would warrant a second look at the orbiter’s heat-resistant tiles of wing edge panels, though mission managers will make the final decision as early as Friday.

Astronaut Tony Antonelli, serving as spacecraft communicator in Mission Control here at the Johnson Space Center, radioed the good news to Discovery’s STS-120 crew, which is preparing for the first of five record-tying spacewalks outside the International Space Station (ISS). NASA’s orbiter project team plans to recommend that mission managers not take time from the crew’s busy schedule this week for the extra heat shield inspection, he said.

“Oh man, that is fantastic news,” Discovery commander Pamela Melroy replied. “We sure appreciate it. Obviously, it’s been a question that’s very much on our minds.”

Analysis still under way

Mission managers had set aside about three hours on Saturday for Melroy and her crew to revisit any suspect areas in Discovery’s heat shield using sensors at the tip of a 50-foot (15-meter) extension of the shuttle’s robotic arm.

John Shannon, head of NASA’s mission management team for Discovery’s flight, told reporters that engineers were about 90 percent complete with their analysis of a Wednesday scan of Discovery’s wing edges and nose cap, and had yet to find cause for concerns. A similar analysis of high-resolution images taken of the shuttle’s belly-mounted tiles as it docked at the ISS earlier today was still under way, he said.

“No one has seen anything that has caused any alarm or concern at all,” Shannon said of Discovery. “It’s a pretty clean vehicle.”

A small piece of ice that shook free from a fuel tank pipe and glanced off aft-mounted tiles as Discovery ignited its engines during a Tuesday launch also posed no risk to the orbiter, he added.

NASA has kept a close watch on shuttle heat shield integrity since 2003, when foam damaged the Columbia orbiter’s wing leading to the loss of the spacecraft and its crew during landing.

In addition to now standard inspections just after launch, shuttle crews perform focused scans if required and also make one final survey - dubbed a “late inspection” - before landing to check for signs of damage from micrometeorites or space debris.

Spacewalk on tap

Melroy said that without the extra heat shield inspection, she and her crew can focus their attention on installing and outfitting the Harmony module. Formerly known as Node 2, the Italian-built pressurized module will serve as the anchor for future European and Japanese laboratories at the ISS, and is the first new room to be added to the station since 2001.

Discovery spacewalkers Scott Parazynski and Douglas Wheelock will step outside the ISS early Friday and, working alongside robotic arm operators inside the station, help install Harmony to the outpost’s Unity module.

The planned 6.5-hour excursion will mark the first of five planned during the STS-120 to deliver the new node, relocate a massive solar power tower, prime the ISS for future expansion and test shuttle repair techniques.

“We’re pretty excited to hear about that because it’ll give us more time with Node 2,” Melroy said of the plan to skip the focused inspection. “We just can’t wait to get inside.”

NASA is broadcasting Discovery's STS-120 launch and mission operations live on NASA. Click here for mission updates and NASA TV from SPACE.com.

• SPACE.com Video Interplayer: Delivering 'Harmony' with NASA's STS-120 Mission
• Test Your Smarts: Space Shuttle Countdown Quiz
• Complete Space Shuttle Mission Coverage