File:KSC-05-S-00171 (ksc 071305 rtf scrub).webm

English: Ok Dave, we are working an issue now on the countdown so, as long as you're here with us you have background on this kind of thing so can you tell us exactly what it is that they are talking about. George, I don't want to be the bearer of poor news but there is a problem with the vehicle that we're examining, right now, it's called a Low Level Fuel Cutoff LH2 low level cutoffs sensor, there's four of them on the vehicle. And if we really don't want the engine to be running at high speed and then suddenly run out of fuel, that can lead to a devastating breakdown of the engine even uncontained failure of the engine, if that should happen, therefore we have four sensors on the vehicle, and it requires two of those to detect a low level fuel in order to cutoff the engines early, before they would run out, and this is only comes into play in special conditions on the ascent, not on nominal ascent, so it's essentially a backup for a backup situation, but the flight director's here and the launch control directors are discussing this issue right now and this could lead to the scrub of this launch, I'm sorry to say, for today, for further testing but we'll have to listen in and and see where they go with this. Looks like the weather is starting to come together for the vehicle's ecos ensors for some reason, did not behave today and so we're going to have to scrub this launch attempt, so once we develop our scrub turnaround plan for you obviously we'll get that back to you, so appreciate all we've been through together, but this one is not going to result in a launch attempt today. We'll probably need some time to determine how long this stand down is going to be, I assume, that's right to know for sure, at risk of being somewhat speculative. George, there are several failure modes we could be in here which could allow rapid turnaround so I wouldn't rule out another attempt tomorrow, that's rather speculative and early information, but at such risk that could still happen for us we'll have to watch several hours and listen in on the technical teams' assessment of this problem.