||2x Quest C6-5||This first flight of the new millennium wasn't terribly auspicious.
We were flying with a battery that we suspect is sulfated -- an old car
battery that a club member brought that hasn't been holding a charge as
it should. Even after having been left on trickle charge for several
days after last use, we found in a preliminary test that it wouldn't even
light the continuity bulb in my launch controller.
Okay, it's a car battery and I have jumper cables -- we hooked it up to my car, blocked the accelerator to rev the engine enough to be sure the alternator would charge, and left it on charge for ten minutes or so; after doing so, it lit the continuity and popped an igniter promptly, so we carted all our stuff down to the field (we can't drive onto the field this time of year due to the very soft, wet ground -- more on that ground condition later) and set up.
First try to launch the Luna 2-18 Express resulted in a complete ignition failure. Okay, tried reseating the battery clips, scraping the launch key in and out to clean the contact point, and tried again. This time I did get ignition, but one of the motors was slow, and I got a graphic demonstration of what I'd been afraid might happen if both motors didn't light immediately: the rocket was kept from immediate pinwheeling by the launch rod, and started off more or less straight, but when the second motor came up to pressure about twenty feet above the pad, the rocket started coning. The anhedral in the main wing did its job, and prevented a simple cartwheel tumble; instead, the rocket imitated a large, slow Corkscrew as yaw-roll coupling kicked in. Naturally, with the reduced thrust and greatly increased drag, the flight was low, but the first motor to ignite ejected with plenty of room above ground -- and the shock cord harness promptly tangled on one wing tip, bringing the rocket into much more of a nose down attitude than I'd designed for.
Landing damage consisted only of a small section of the tube mouth buckling inward, and it was easily popped out; no lasting harm done -- and in the process, I got confirmation that the rocket could survive a single motor ignition or late ignition (though without the second motor, it might well have been on the ground before deployment).
||The battery once again failed to ignite the cluster, though it had
lit several single motors with reasonable promptness in between.
This time, the failure was complete, even after disassembling my controller
to scrape the safety key contacts and once more grinding the battery clips
into the soft lead terminal posts. I had given up and packed my stuff,
planning to hold the prepped rocket until next week's launch in Monroe,
when another group arrived bringing their rockets, pad, and a freshly charged
and very healthy battery. I waited for them to get set up, and loaded
up the Cobra on their pad.
This time, all three motors lit promptly. and the rocket shot skyward, completely nominal with a slight curve during the burn of the C6-7 that lasted beyond the burnouts of the B6-6 motors. Ejection seemed early -- the rocket, of course, was climbing faster than it would have been with a cluster of only B6-6 motors -- and the shock cord, which I'd commented during prep was about due for replacement, parted at the airframe end.
Conditions were so calm that the light payload section still recovered on the edge of the field, only about a hundred feet from where the airframe came in. The bad news is, the airframe stopped tumbling and stabilized into core sample attitude about 150 feet up. The good news is, the ground was so soft and the body so stable that when it took a core sample about two and a half inches deep, there was no buckling or crumpling of the tube -- all I had to do was remove the grass and soil from the tube mouth, and I'll be able to replace the shock cord and fly again without further repairs.