If you’ve been following our Tweets (www.twitter.com/SEGames) you’ll know that we had a problem today with the pulley and the cable. I was not at the lake-bed operations today (I was watching it on ustream along with many others) and I am not party to the after-mission meeting where this is all being discussed. So, take what I’m writing here with a grain of salt. I’ll try and differentiate between what I know and what I think I know.
I know that the cable broke. Everyone has confirmed this – I have seen pictures of it (and am waiting to get them from Danny Leafblad of the KCSpace Pirates so I can put them on this blog). I also know that the pulley that the cable was threaded through (the steel cable goes from the winch through the pulley and to the helicopter) broke. I have seen pictures of this, too.
What appears to have happened (and remember, this is subject to update based on the after-mission analysis going on now) is that the pulley broke first. It cause the cable to bend or catch on something. This weakened the cable so that it broke. No other links in the tether chain broke, and some were designed to break at forces well below the level necessary to break a ‘healthy’ cable. Because these links did not break, I’m forced to conclude that when the pulley broke, it caused the cable to break.
Now, why did the pulley break? Perhaps they know by now (and I certainly will update you when I do). It’s inconceivable to me that both Ben Shelef (the organizer of these Games and the engineer who designed this system) and the NASA review team would have overlooked the issue of the pulley rating. I’m guessing that somehow the cable was able to jump off of the pulley wheel and somehow lodge itself between the pulley wheel and its mounting bracket. Either that or the pulley itself was defective. Let me emphasize that this last paragraph is speculation on my part and when I know the answer, I’ll let you know.
I’ve also heard (second-hand) that there is no chance of the helicopter flying tomorrow because of some scheduling conflict, so further testing of this sort may need to be put off until just before the Games. Again, I’m not sure, but will let you know.
On the bright side, overall the system seemed to perform very well; the helicopter and winch we’re able to work together to reel-out and reel-in the cable satisfactorily. The winch operator, tether handler and helicopter personnel all were able to practice working together under real (not simulated) conditions. The NASA TV team was able to get some practice in filming helicopter and winch activities and, if you tuned into their Ustream live broadcast, you were able to see it. The target at the top of the tether functioned properly. I am unaware at this time of any other significant problems that happened during the operation.
Also on the bright side, the TRUMPF people say that there laser is all set up and operating at full-capacity with no issues. This means that both the Kansas City Space Pirates and LaserMotive should be able to laser-qualify their climbers (checking for reflections, etc.) tomorrow.
So, that’s the status. I’ll update you as soon as I have more/better information.