Reilly: 'They were ready to fly'
CNN's Miles O'Brien, left, discusses the shuttle problem with NASA astronaut Jim Reilly.
YOUR E-MAIL ALERTS
KENNEDY SPACE CENTER, Florida (CNN) -- NASA officials scrubbed Wednesday's scheduled launch of the space shuttle Discovery because of a problem with a low-level fuel sensor in its external fuel tank.
CNN space correspondent Miles O'Brien discussed the situation with astronaut Jim Reilly soon after the launch was called off.
O'BRIEN: As I understand it this is a sensor ... it detects the fuel is running out of the main engine. It's a redundant sensor, but nevertheless it is one of four. It's a very important piece of equipment that's inside the main engine. NASA astronaut Jim Reilly has more information for us.
REILLY: What we've got right now is we have one of the four low-level cutoff switches in the hydrogen side of the tank and those things are designed to sense when we get to a low-level cutoff so that if we get to a low position in the propellant it will start to spin the engines down so you don't shut them off catastrophically.
O'BRIEN: You don't want a quick shutoff. This is a device inside the orange fuel tank?
REILLY: That's what we have right now is that we have low-level cutoff switches in these two tanks, the oxygen and the hydrogen side
O'BRIEN: Each of them have the switches. There are two of them in each?
REILLY: There are four in each is my understanding. We're still working to get some information on that. What we had is one of the four that's in the hydrogen side, was the latest information we have gotten, was one of the four has failed the test. And we have to have all four working for that to be a launch commit criteria -- to meet the requirement.
O'BRIEN: So it has to be backed up three times, essentially in order to fly, it's that critical a device? What do we know about access to it and fixing that kind of a thing; that's the big issue.
REILLY: I don't know that yet. We're busy looking at that. The mission management team is looking at what it is going to require to repair this, what workarounds they might have, what repairs are required. We understand that the place for the latest information, they are going to have to de-tank and they will have to remove the propellants from the tank. Then they will be looking at what it takes to replace this one faulty switch.
O'BRIEN: So we don't know if this is something that can be done at the launch pad.
REILLY: That's true, they are planning, a mission management team. ... We will have a news conference here shortly that will go into the engineering details at the fix, what they are looking at and what it will require. And of course, more importantly, how long of a turnaround will it take for us to get ready to go back to fly.
O'BRIEN: That is the key question here. NASA wants to launch the space station under daylight hours and that poses a limitation because they can only do that at certain times of the day, obviously to meet the international space station. By August, they are running out of daylight for this go around of launches with five-minute launch windows each day. If they can't get the shuttle in the orbit before then, they are going to have to wait until September to do that. Do we know yet if this is something that could take that long? I guess not at this point, right?
REILLY: We don't know at this point. We're just waiting to hear what the engineers have to tell us about what it will take to fix it.
O'BRIEN: What's your inkling on this -- have you ever run into this kind of problem before?
REILLY: They have had a similar issue on a previous flight, but it was able to cycle itself is my understanding. We're waiting right now to really get the experts to tell us what they think it will require.
O'BRIEN: So we're past the point where this is something that can be recycled. They obviously tried to do that.
REILLY: The crew is coming out of the vehicle right now, so we're not going to fly today.
O'BRIEN: I'm sure that's very disappointing for the crew. You've been through a few scrubs yourself, what goes through your mind at this point?
REILLY: At this point, Charlie Camarada, is in the middeck with his hands so of course they are all very disappointed. They were ready to fly. The weather was finally cooperating with us. Everything was looking good. So we have this one thing. The nice thing about it we are doing the right thing as far as seeing these things and stopping the count because it's not in what we consider to be a minimum configuration for launch.
O'BRIEN: It just goes to show you, all morning long we talked about the weather. We should be reminded this is an incredibly complex vehicle -- the most complex vehicle ever devised. A million parts. The fact that they all work well enough to launch ever is pretty amazing when you think about it. So many possibilities.
REILLY: And it's been such a clean flow right up to this point. Everything was looking good. I'm sure they are very disappointed. They will be coming back to crew quarters this afternoon. Of course the mission management team will be giving us more information shortly.
|© 2007 Cable News Network.
A Time Warner Company. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines. Contact us. Site Map.