Flight Log for 10 April 1999, Boeing Space Center, Kent, WA

High overcast with lower partial cover, appr. 2000' AGL; wind variable direction and 0-15 mph.  Best flying weather in months.
Model Flt 
Recovery Type Motor Comments
24" nylon parasheet
Aerotech RMS 29/40-120 F40-4
I got a lot of ribbing from people for repeating the combination of rocket and motor that caused such a disaster at NSL just under a year ago, but I was confident that I'd learned the cause of that and one subsequent deployment failures, and I wanted to verify my confidence.  I was careful to ensure that the launch rod was angled well away from both all spectators and fliers, and the Boeing plant.  After one ignition failure -- my first in which a Laser Fire igniter burned, but failed to ignite the motor -- I opened the rear closure, verified that the propellant was still in a condition that would permit ignition, and reloaded with a new, stiff Copperhead.  This time, despite ignition with a low-tech Estes controller connected to a Pratt battery pack, the motor ignited immediately, and the rocket lifted slowly off the pad.  As I expected, the flight wasn't very high, but it was completely stable, and though I got approximately one second of bonus delay, ejection was still only about two seconds past apogee and thirty to fifty feet above ground.  Vindication has been acheived!
18" nylon parasheet
Estes D12-3
Continuing the theme of minimum motors for the rocket, I repeated my well proven "stunt" of launching my Spike on a black powder D.  As always, the flight was completely predictable; low, slow, but absolutely straight, with ejection just past apogee.  No surprises, and not much walking at all.
24" nylon parasheet
Aerotech RMS 29/40-120 F52-5
With the certification (finally!) of the F52 reload in 1998, I bought a couple of them, and this was my first time flying one.  This is a much better motor for the Thug than the F40; it gets off the pad much more smartly, and seems to give up much less to gravity losses; the altitude seems greater, despite violating the 2:1 ratio that is touted as ideal for maximum altitude -- I suspect this is because the F40 violates the rule of getting up to "cruise" speed quickly.  Ejection was very close to apogee; with a more vertical rod position (as would be indicated on a less breezy day), I think this would be a near-perfect combination, much like the F62-4.  I had the rod angle just right, though; I almost dropped the rocket on the LCO table.
24" nylon parasheet
Aerotech G40-4W
Digging through my motor stash, looking for a motor suitable for a quick prep and flight (I didn't want to spend the time to assemble another reload, since the day was wearing on), I found a G40 I'd bought for NSL -- a purchase made around a year ago.  This seemed like a good motor for the Thug, so I prepped up and put it on the pad.  I haven't compared thrust curves, but the G40 seems to get off the pad faster than an F40 in the same rocket; it may start with higher thrust, and tail off lower, to come up with the same average.  In any case, it was a much more satisfactory flight, with substantially more altitude and less of the precarious feel during liftoff.

Back to 4 Apr 1999

Forward to 24 Apr 1999

Back to Launch Logs page.

Back to my Home page.