An independent commission of aviation experts says the U.S. space shuttle is much safer to fly since the loss of the orbiter Columbia in 2003. The panel says the U.S. space agency NASA has accomplished most of the safety modifications recommended by the investigators who probed the causes of the Columbia accident. But, as VOA's David McAlary reports, NASA is not expected to finish them all before the planned July 13th launch of the shuttle Discovery to the International Space Station.
The panel's job is to advise NASA on how well the agency has done to eliminate the causes of the Columbia accident and return the remaining three shuttles to orbit safely. The commission's co-chairman, former astronaut Richard Covey, says the agency has failed to meet all safety requirements established by the accident investigators two years ago, but has nevertheless done well.
"Efforts undertaken by the agency have been extraordinary and outstanding. I know from our reports and from the things you have had heard from NASA themselves, you know how much work has gone in to the return to flight effort over the last two years," Mr. Covey says.
The shuttle Columbia disintegrated after a piece of hard foam insulation peeled off the huge external fuel tank during launch and punched a hole in the wing. This hole allowed extremely hot gases generated on re-entry into the atmosphere to penetrate and destroy the orbiter and kill its seven astronauts minutes before landing.
Panel member James Adamson says NASA has eliminated almost all chances that foam could shed from the external fuel tank again, but it is still unsure about how to prevent ice caused by frigid liquid hydrogen and oxygen fuel from breaking off during launch and causing orbiter damage.
"While there is a gap between the debris allowables and the arbiter's ability to withstand impacts, we think that the proximate cause of the damage to Columbia has been eliminated without doubt," Mr. Adamson says.
As a result, Mr. Adamson says, NASA has significantly reduced the chance that it will have to apply unprecedented techniques it has developed to inspect and repair a shuttle in orbit. That is important because the panel believes NASA is not ready for in-flight repair. It says the agency has lagged behind recommendations by the Columbia accident investigators in devising ways astronauts could fix small cracks and holes in heat-protective ceramic tiles and other parts of the surface once in orbit.
Panelist Joseph Cuzzopoli is a veteran of the team that took a decade to develop the tiles in the 1970s. He says the lack of progress in tile repair methods is not surprising.
"Here we're trying to do tile repair, which is just as difficult as starting over again, and ask NASA to get it done in two years. It is very difficult," Mr. Cuzzopoli says.
The commission says its task is not to determine if shuttles are ready to fly again, but to provide its observations so NASA can make that decision. On balance, panel co-chair Covey says the space agency has met 95 percent of the accident investigators' recommendations for safety upgrades.
Joseph Cuzzopoli puts it this way, "From NASA's inputs to us, we feel it is a safe vehicle to fly."
NASA officials are to meet later this week to make a formal decision about Discovery's readiness for launch on the planned date of July 13. Agency chief Michael Griffin says he expects a healthy debate during the meeting.