Blacksky Research Optimal 65
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I received this kit in mid 1997 and was quite enthralled. The aluminum fins were the most attractive feature but I also liked the fact that there were no spiral grooves to fill in the c-phenolic airframe tubing. I haven't seen similar tubing around since Scott Bartell (the proprietor) stopped selling kits. I also liked the aluminum baffle and bulkhead plates. The nose cone looked like a typical Loc/PML plastic ogive. The "65" means 65mm diameter airframe (2.5" for any USA or Burma citizens reading this). Blacksky also offered 100 and 150 mm versions with a similar design. This kit seemed more sophisticated compared to the cardboard kits I had been working with. Of course, since I have a thing for the classic three-fin 20:1 performance rockets, that helped as well. The Optimal 65 had a nice modular design; everything screwed together, it had three interchangeable configurations (motor only deploy, electronic main, or electronic dual deploy), and two different diameter motor mounts...all of which could be screwed together in place. It had very nice instructions and CAD drawings, with only a couple of minor mistakes, which were easily recognized and corrected via e-mail with Scott. Originally, the kit came with a parachute from the legendary Bob Stroud, but by the time I ordered the kit, Scott's deal with Bob had fallen through. I used an appropriately sized RocketMan chute.
I happily jumped in and finished construction in short order.
I used 30 minute hobby epoxy throughout. I had one of the fins black
anodized, and left the other two natural, using two coats of clear coat to seal
them. I used the same industrial black, white,
and orange paint scheme as I had with the Loc Legacy, using hardware store
Krylon spray paints. It looked good!
I decided to go for level one certification, using a BlackSky Altacc to record the flight data, motor ejection charge and "main-only" parachute deployment. I had purchased Chuck Rogers' ALT v4.05 simulation software, and an AeroTech H242T motor for the attempt. My only screw-up was that I had inadvertently loaded two of these motors in the simulation software, and thus convinced myself that a "long" ejection delay was appropriate.
The soonest and nearest launch was a ROC launch November of '97, so I packed everything into my wife's Volvo station wagon and headed down I-5 to Lake Lucerne. My brother and his son helped me prep and Rick O'Neill of ROC agreed to keep an eye on me for the certification. I used a BlackSky igniter and all went well up to apogee. But....no parachute. It turned over and proceeded to pursue a ballistic trajectory down, and down, and down. Finally, after the rocket had lost half its altitude, the recovery charge fired and much to my amazement, everything deployed and it landed gently without damage. That was very lucky, and I was relieved to get out of there with my level 1 certification. Here's an Excel version of the Altacc data, and you can see why I was so nervous:
1,400 feet is no big deal, I think I had done better in my Estes teenage years, so I was anxious to improve on that and the Optimal 65 could easily use one of the newly released 38mm J350s for a level 2.
In preparation for the level two attempt, I detached the fins and soaked the two natural finish clear coated fins in paint thinner to remove the clear coat and had them anodized grey. I re-attached all three using hobby epoxy to augment the screws, boned up on the written test, ordered the J350 hardware, and was ready to go! LDRS XVII at Bonneville seemed like the appropriate time and place. I rented a green Taurus (I knew there would be salt caked on the undercarriage), and my best friend Keith flew in from Houston to make the drive from silicon valley to Utah. The drive was quite a kick; it's fun to have a long male-bonding road trip once in a while. While Keith was driving, I studied for the test, and while I was driving, he quizzed me. Bonneville is a fantastic launch site and the accommodations across the state line in Nevada were nice and cushy. I passed the written test with a 100%, and all that was left was the flying. I had configured the Optimal 65 for main-only deployment, with motor ejection charge and the Altacc for data. My screw-up for this flight was not completely arming the Altacc, so I never got the flight data. By this time, I was using Rocksim, and the flight was probably about 7500 feet, which correlates to results from other fliers with similar motors. Having been scared of late deployment from the previous flight, I used a medium delay and the chute deployed a little early, resulting in a small 1/2" zipper, but generally speaking, a nominal flight. Jerry Vaughn was the observer and he signed off on my level 2.
On the way out, Keith and I made a land speed record attempt in the rental Taurus category, and got up to 100mph. I'm still looking for the speedometer photograph to prove it, and when I find it I'll publish it here.
I have never gotten around to fixing that little 1/2" zipper, and the wonderful Optimal 65 sits idle in my garage while I've been working on newer projects. The "Optimal" series lives on in a small way......the cool aluminum fin sets are still available from Blacksky and are used for the ARLISS student rocket projects at Black Rock. I recently bought a set just in case...