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Ex-NASA engineer: Waiving safety margins 'crazy'

Ex-NASA engineer Bob Daugherty




Don Nelson
National Aeronautics and Space Administration (NASA)
Space Exploration
CNN Access

(CNN) -- A piece of insulating foam broke off the external fuel tank during Discovery's liftoff this week, casting a shadow over the space shuttle's return to flight 2 1/2 years after the Columbia disaster.

NASA has suspended the fleet until the foam problem is solved. CNN anchor Miles O'Brien spoke Friday with former NASA engineers Don Nelson and Bob Daugherty about how the space agency has handled the launch.

O'BRIEN: Do you have a good feel whether Discovery is safe for return?

NELSON: I don't think we're going to know that until we get the results back of the analysis that they're doing at Johnson Space Center [in Houston, Texas], and I understand that's going to be another two days -- where they're analyzing this chip that's up around the forward wheel well.

That's their major concern now, whether or not that chip is going to give them some problems during entry with the thermal protection system.

O'BRIEN: How concerned should we be about a chip near that landing gear door?

NELSON: Landing gear doors have always been a problem for us. We've always been concerned about leaks around those doors, and any time you have a tile around there that gets chipped or whatever, you need to be very, very concerned about what's going on.

O'BRIEN: Bob Daugherty, you may remember his name -- he was a person who sent several e-mails to fellow engineers in the shuttle program, expressing concerns about the situation with Columbia, asking some pointed questions about the way NASA was managing that problem or perhaps not managing it. Clearly, it wasn't managed well.

I spoke to you a little while -- the day before [Discovery's] launch, and you were concerned that some of the same management mistakes that led to Columbia are still at work inside NASA. Tell us about that.

DAUGHERTY: Yes, 2 1/2 years ago, as you know, I wrote an e-mail where I actually used the words, are they crossing their fingers and hoping for the best?

And then I -- just before launch -- I see a press conference where actually the mission-management team had their fingers crossed and were hoping for the best with regard to the hydrogen-fuel sensors.

My concerns really are for the long term. I was angered when I saw that they were prepared to waive a flight rule and actually throw away a layer of safety, with one of the hydrogen fuel sensors.

O'BRIEN: In response to that, NASA said, well, we've made other upgrades, which make it unnecessary to have four operative sensors. In other words, the black box that operates is better; therefore, we can waive that rule. And you know, the point is that you're never going to have a perfect vehicle. What do you say to that?

DAUGHERTY: I say that's crazy. You do not throw away a safety margin on the ground. You know, that redundancy is for when you're flying.

You never throw away a margin while you're sitting on the ground in comfort. Those things are designed for when you're flying. This is an aging vehicle. Those failures and unknowns are probably there because it's an aging vehicle, and you're crazy to throw away that safety while you're sitting there on the ground.

O'BRIEN: Don Nelson, would you agree with that? That decision to fly with -- although ultimately those fuel sensors, we should point out, worked just fine on launch day, and all four of them were operating, but the decision was in the works there to bend the rules, change the launch rules and fly with only three. Does that speak to problems with the way NASA is managing the shuttle program?

NELSON: It certainly does. They had 2 1/2 years to review their flight procedures ... coming back and just arbitrarily saying, hey, we're OK -- they were on the ground for what? A week, two weeks? And that just made the flight of the mission cost more.

O'BRIEN: The foam that fell off, that big piece, Don, when you heard about that, what were your thoughts, and do you think that NASA has responded appropriately to that problem?

DAUGHERTY: I watched when it came off, and it's a pretty good chunk. It looked like a bird as it came off in slow motion. It was that big. And the response is, to ground the space shuttle, that's probably the thing they should do.

What really bothers me is that I wrote a letter to the president telling him that we shouldn't have a full crew on this thing. We should only fly four people because of situations like this. The Russian space programs also said only fly four people because of the limited capability they have to use the Soyuz to bring the crew back.

Now we've got seven people up there, and we're going to have to find some way get them back. It could be -- if we get into the situation where the shuttle can't bring them back -- then you've got to the first of next year. And what bothers you is that the oxygen generators have been showing all sorts of problems for the last couple of years. With nine people up there, we could have another major catastrophe.

O'BRIEN: Bob Daugherty, tell me a little bit about this foam, especially given your experience inside Columbia and trying to get people to focus on the possible damage foam could cause there and much of that falling on deaf ears.

When you heard about a big piece of foam falling off of Discovery's fuel tank, what went through your mind?

DAUGHERTY: Well, 2 1/2 years ago, of course, as it did to everyone who saw the impact, it was obviously a huge impact, and it appeared to me that the planning, or the plan B, if you will, to deal with any potential concerns during re-entry on that weren't there. That's what concerned me. I had no clue whether or not there actually was a hole, and I was concerned that the planning to deal with any potential problems went on. And that's why I wrote the e-mails I did.

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