NASA launches investigation into shuttle pad damage
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 2, 2008
The shuttle Discovery's heat shield showed no obvious signs of damage during a slow back flip before docking today at the international space station. But it will take NASA managers several more days to complete their analysis and examination of high-resolution photos shot by the station crew.
Back at the Kennedy Space Center, meanwhile, an investigation has been launched to find out what caused extensive damage to launch pad 39A as it was pounded by Discovery's main engine and solid rocket booster exhaust plumes during liftoff Saturday.
Photos of the damage can be seen here.
LeRoy Cain, chairman of NASA's Mission Management Team, said heat-resistant fire bricks lining a 75- by 20-foot section of the "flame trench" that diverts the booster exhaust away from the pad was blown out like shrapnel as Discovery climbed skyward, littering the pad perimeter with concrete and mortar debris and seriously damaging a security fence some 1,500 feet away.
Built in the 1960s for the Apollo moon program, NASA's shuttle launch pads have been enduring the 5,000-degree booster exhaust and enormous pressures associate with shuttle launchings for decades, but Cain said this was the most severe post-launch damage ever seen.
"From the standpoint of the ongoing mission, it's not going to be a concern to us," he said. "The imagery and the analysis teams have pored over the liftoff imagery and all of the data that we have and they have assured us they have seen nothing in the way of any of this debris coming back at the vehicle, if you will. So we don't have ay concerns for the ongoing mission.
"However, as you can imagine we do have concerns because we're planning to go launch off this pad again, of course. So we have an investigation team that's already being assembled to go look at this damage ... to ascertain exactly what happened here. ... They'll put together some options and a forward plan of action to get the pad cleaned up and repaired so we can go launch of it again. Part of those discussions includes pad B and there are lots of options out there that need to be developed."
He said the flame trench and support structures at both of NASA's shuttle launch pads are routinely inspected and "obviously when you have an area (of damage) this large over the course of one event, something else is going on, or has gone on, to result in this kind of damage. We need to go understand what that is."
NASA plans to complete the space station and retire the shuttle fleet in 2010 to focus on developing a new spacecraft expected to debut around 2015. As part of the Constellation program, aimed at eventually building a base on the moon, NASA plans to launch the remaining shuttle flights from pad 39A while modifying pad 39B for use by the new Ares 1 rocket and its Orion crew capsule.
But pad 39B still has a role to play in the shuttle program. The shuttle Atlantis is scheduled for launch Oct. 8 on a mission to service the Hubble Space Telescope. Launched into a different orbit, the Hubble repair crew cannot reach the space station for "safe haven" if any major problems develop. As a result, NASA plans to have the shuttle Endeavour ready for launch on a rescue flight if needed.
The current plan calls for readying Endeavour for flight on pad 39B while Atlantis is processed and launched from pad 39A. If a rescue flight is needed, Endeavour would be moved to pad 39A and launched from there. But that plan assumes pad 39A can be repaired in time.
Cain said it was too early to speculate about the eventual impact of the pad damage seen after Discovery's launch, but he said he had no concern "with having to delay the HST mission. We just have to figure out what's the course we want to go. We need both launch pads. ... That's not a negotiable term at this point."
NASA can process Endeavour on pad 39B, but the complex has not been maintained as required for an actual countdown and launch. Any major change to the current plan for the Hubble mission and its rescue flight likely would cause downstream delays for the first test flight of the Ares 1 rocket next year.
"Our plan for the Hubble mission, the next mission in October, is that we will roll that flight vehicle out to pad A and we will launch from pad A. At the time of launch, we will have the launch-on-need vehicle rolled out to and on pad B. ... There are some issues associated with payload and the payload changeout room and the capabilities we have at pad A as opposed to pad B. We've started to do some work at pad B as it relates to the Constellation program that's coming on and so we would have to change some of our planning ... as it relates to work going on on pad B. That's both from a modification standpoint, but also from a routine maintenance standpoint."
To use pad B for a launch, "there are some things we would want to go do," Cain said. "Do we have time to still change the path we're on and go do that? We'd have to study that. My answer today would be yeah, I believe we could figure out how to go do that. Will there be impacts to both the shuttle, potentially the station and no doubt the Constellation program? I'm quite certain there would be. All of those things will be in the trade space.
"It's early for me to be talking about it in terms of really knowing what we have here at pad A because I don't know what we have. And it may not be an option we would want to pursue at all. But could we? I believe the answer is yes. But there would be some aches and pains with that probably for all three programs from a schedule standpoint."
While Cain was discussing the launch pad with reporters at the Johnson Space Center, astronaut Gregory Chamitoff's Soyuz seat liner was being moved from Discovery to the Soyuz TMA-12 spacecraft docked to the station. The transfer was completed at 6:35 p.m. and Chamitoff officially became a member of the Expedition 17 crew, replacing Garrett Reisman, who will return to Earth aboard Discovery.
Astronauts Michael Fossum and Ronald Garan, meanwhile, are preparing to spend the night in the station's Quest airlock module at a reduced air pressure to purge nitrogen from their bloodstreams prior to a spacewalk Tuesday. The goals of the excursion are to prepare the Kibo laboratory module for attachment to the station and to retrieve a space shuttle heat shield inspection boom left on the lab complex last March.