Panel: NASA has work to do before return to flight
(CNN) -- Five weeks before the scheduled launch of the Discovery, the panel charged with certifying that NASA's efforts to ensure the space shuttle would be ready said the agency still has work to do, and cited concerns over ice possibly endangering the craft.
The Stafford-Covey "Return to Flight" Task Group is the independent oversight panel chartered by NASA to certify that the agency has completed a 15-point "do list" drawn up by the Columbia Accident Investigation Board.
To date, the task group has "closed out" 12 of the board's recommendations, with analysis of the remaining three still incomplete, said the task group, which met Wednesday in Houston, Texas.
But task group co-chairman Richard Covey said the panel and NASA are on the same page regarding the shuttle's eventual readiness for return to flight, and said he saw no show-stoppers on the horizon.
"We don't see anything out there that we have big questions about, that are not the same questions that the program is looking at," Covey said.
Panel member Joseph Cuzzupoli echoed other panel members in his praise of NASA's efforts.
"NASA has done a helluva good job on making this vehicle a very safe vehicle, and their continuing efforts to analyze what the risk is is very important. As long as they stay on that track, we'll be OK."
The task group plans to make a final report to NASA Administrator Michael Griffin before the end of the month, when a critical Flight Readiness Review for Discovery is scheduled.
But the decision on whether to approve the next mission does not belong to the panel. "We don't make a recommendation on return to flight, we are advisory to the administrator," Covey said.
The shuttle fleet has been grounded since February 1, 2003, when the space shuttle Columbia broke apart over Texas while on landing approach to Florida's Kennedy Space Center, killing all seven astronauts on board.
Six months later, the investigation board, led by retired Adm. Hal Gehman, concluded that foam insulation broke off during liftoff from the shuttle's external fuel tank, striking and cracking a panel on the orbiter's wing. When the shuttle re-entered the Earth's atmosphere, searing hot gases seeped into the wing and incinerated the spacecraft.
The major issues confronting the task group involve risk and damage assessment related to ice that builds up on a shuttle's external tank just before launch, when it is filled with super-cold liquid oxygen and hydrogen fuel. Pieces of that ice could break off during liftoff and damage a shuttle orbiter in much the same way that falling foam damaged Columbia, panel members say.
"Ice is a source of debris that could be as serious or more serious than foam," said Cuzzupoli. "We should probably have started the ice debris (analysis) earlier than we did. Foam is understood now. And ice isn't. And we started maybe too late. But right now we're catching up."
In late April, Griffin cited concerns about the ice when he postponed from May to July the launch of Discovery.
NASA engineers are conducting ice damage tests and giving the results to the task group.
NASA managers are scheduled to hold a meeting June 24 on the ice analysis, and the Stafford-Covey group is to make its final call on the issue three days later.
The panel's other unresolved issue, which appears to be headed for resolution, has to do with NASA's ability to repair an orbiter's "thermal protection system" in-orbit.
The underside of a space shuttle is covered with insulating tiles, and the edges of the wings are clad with reinforced carbon-carbon panels. Together, they make up the TPS, which is designed to ensure the shuttle can withstand the heat of re-entry. Before the Columbia accident, astronauts had no way to inspect for and repair any damage to the TPS that they might find.
But, since the Columbia accident, NASA engineers have designed an Orbital Boom Sensor System, a second robotic arm covered with cameras and other instruments and mounted in the shuttle's payload bay.
Astronauts should be able to use the boom to inspect the panels on an orbiter's wings and nose cone for any damage that might have occurred during launch, panel members say.
Engineers also have been developing and testing RCC plug and crack repair procedures, and tile-repair techniques, for use in the event of damage.
Two such methods will undergo limited testing by Discovery astronauts, but mission managers acknowledge that their techniques will likely need to be modified before they can be certified.
Most NASA engineers agree that future astronauts would never be able to repair a hole the size of the one that doomed Columbia.
The Stafford-Covey panel acknowledges it is divided over the recommendation's wording. The investigation board's final report said NASA should "develop a practicable capability to inspect and effect emergency repairs to the widest possible range of damage to the Thermal Protection System."
The sticking point has been a difference of opinion among panel members as to what the investigation board meant by "practicable" and "widest possible range of damage."
Task group co-chairman Gen. Thomas Stafford eventually met with Gehman and several members of the board to clarify the intent of the recommendations.
"I told him ... basically we had no repair, or a minimum of repair capability that really hadn't been verified to a major degree, said Stafford. "They tried a lot, they worked all the major technical problems ... remember, the tile and RCC were never designed to be repaired. And exactly what was brought out was, 'Do the best you can do, and go fly, and keep working the issue.' "
NASA has from July 13 to July 31 to conduct a daytime shuttle launch on a rendezvous trajectory with the space station.
If Discovery does not launch during that window, shuttle managers would have to wait until September 9 for acceptable lighting conditions to return.