On 10 Nov 2002 23:49:09 -0800, David Masten <[EMAIL PROTECTED]> wrote:
>If experience is what you get when you don't get what you want, then we >got a lot of experience. I was trying to figure out how to describe our day. I didn't want to say we were successful, because we weren't entirely successful. But the day wasn't a failure, either. Neither were any of the flights. They all went up, they all went down, and they all recovered (mostly) intact. (BTW, the next person who leaves the launch complex on foot without a radio is going to answer to me for it. That's a safety violation. We don't just use a recovery vehicle because it's faster, we use it because it's safer. If you go out of earshot of the blockhouse, bring a radio with you. If you don't have a radio, bring someone who does.) >For the first flight we flew KISS 3 on 4 liters of propellant, at MECO >the altimeter got confused and popped the recovery system. We are still >not sure what caused this. The chute was ripped up pretty bad, but still >slowed the vehicle down enough to recover with very minimal damage. That it survived in any useful fashion is a tribute to the ruggedness of Rocketman parachutes. Ky builds 'em tough. Highly recommended. >The second flight was a KISS-Beta flight with a solid motor built by >Jerry Irvine. The motor was an excellent performer but the Beta booster >fins weren't up to the task. A split second before MECO the fins >seperated from the body. From the OP, in binoculars, it looked more like a second and change. I thought something had gone wrong with the nozzle, because the plume was turning sideways - but it was the whole vehicle turning sideways. Another tribute to ruggedness, this time Dave Weinshenker's overengineering of KISS Beta. It isn't every rocket that can get sideways at Mach 0.8 and survive intact. The halves of the rocket separated, and the parachute opened, just as if it had been planned that way. The fin failure was about as benign as it gets, and another tribute to Dave W's engineering. The fin attach points are intact, as are the parts of the fins inside the lower body tube. The fins themselves failed, breaking off at the body tube. I'm also wondering if some of the fins didn't break off after the vehicle got sideways, instead of under thrust. I think that's what happened, because the initial slew was fairly slow and graceful. It was only after it slewed around a fair amount that it began to tumble. That would also account for the two halves separating immediately after MECO. >On the third flight we flew KISS 3 with a 5 liter load of propellant. >The original plan was to fly with a 7 liter load, but since the >velocities were expected to be similar to the KISS-Beta flight, and both >boosters had similar fin designs, we cut back the load and thus peak >velocity. Also, we went on timer instead of altimeter for recovery >deployment this time. Oh, is that what happened. I wish someone had told me that; I thought I was looking at a lawn dart. >Chute deployed apropriately, but the vehicle was >travelling fairly fast (large horizontal component due to winds). The >chute did not fully open (and/or was ripped) and a fin was slightly >damaged on landing. We probably should have aborted that launch. Between the high wind and the baro altimeter problem, we were asking for trouble, and we got it. The parachute didn't change configuration on the descent, so it had already opened as much as it was going to. I heard a ripping sound for about a second which it deployed, which was pretty loud for just canopy popping. If we're going to continue to launch in windy conditions, we need an anemometer, an easily leaned launch tower/rail, and a good 4DOF to tell us how far to lean the rail. >On both KISS 3 flights we had terrible engine chug. We need to try >duplicating this in static tests, and find the solution before we move >on to other engines. We cannot have this problem on Spike or POGO. Another change we need to make is that everyone takes some Tylenol before we go out - to cool off their launch fever! The default action always seemed to be to launch. That's backwards. Given comm problems, which we had all day, that leads you to launch when someone tries to tell you not to, but you don't hear him. Next time we launch, I want to hear final confirmation from the pyro operator, final confirmation from TRACON, positive confirmation that the air and ground are clear, and positive confirmation that all observers are ready to observe. In the absence of these confirmations, we HOLD. We are under no obligation to launch on any given day, or in any given month. Our goal is reproducible flight, again and again and again. If we fly in such a manner that we can't reproduce the flight, like because we broke something, then we fail. We didn't fail on Sunday, but it wasn't because we made the right decisions; it was because we were lucky. Let's not be lucky. Let's be smart. Let's leave our launch fever in town, and take our prudence and our caution out to MTA. -R -- [EMAIL PROTECTED] "The only time an aircraft has too much fuel on board is when it is on fire." -Sir Charles Kingsford Smith _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
