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Two-Stage Rocket | ![]() |
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Success! My most ambitious project ever was my two-stage NorthStar from Rocketdyne Systems. This project was built and flown in the summer of 2001 at Blackrock. Having successfully flown a K motor in a Rocketdyne Systems NovaStar the previous summer at Blackrock, I was ready to move up in complexity and size. I felt I would just be covering old ground by flying another K moter, yet I did not feel that I was ready for Level 3, or that I even liked the motors that were available at that time. I needed something like a Level 2.5 project. I have always admired the NorthStar, but was really impressed with the NorthStar Two-Stage, a huge (for me) rocket: 15 feet in length, 5.5 diameter, 16 pounds or more. I had had great success with a G-Whiz electronics package and saw that the enhanced version of the G-Whiz supported two-stage ignition. I decided the two-stage project was for me. I used my homebrew method of soaking the Kraft body tubes in liquid marine epoxy, an incredibly durable epoxy dip from Johnson and Company in Marina Bay, California. This epoxy is normally used to harden wood for boating. After dipping the tubes, which are made of unsealed Kraft paper and soak up the epoxy like a sponge, I let them hang outside for two or three days, and they became hard as phenolic but with a softer result. This is the same method I used on my K motor rocket from RDS. I built all fillets internally with microballoons and two-inch strips of fiberglass. This allowed me to use simple fiberglass strips as outside cosmetic fillets, which produces a minimum fillet. I have found that with super-large rockets, endless fillets of external epoxy can add up to extra weight with no enhancement in strength. I decided to use a K-1050 motor in the booster and a K-250 in the sustainer. These were the two biggest motors available at my certification level. I took the rocket, newly christened "Never Say Never Again," to the Aeronaut launch in Blackrock, Nevada, the last week of August 2001. I arrived at Blackrock early on Friday and flew various rockets for the fun of it, then devoted Saturday to prepping and flying the NorthStar Two-Stage. It took all day to prep the rocket, because I had a failure in my G-Whiz 2 electronics. Luckily, I had set up camp next to Rob Briody; he immediately saw continuity problems in my test-up and said that the G-Whiz I was using had come from a batch with chips that were overcooked in the electronic oven in Watsonville, California, and that they would never work. Rob lent me his own G-Whiz 2, which was military grade and dipped in epoxy. I got the rocket to the RSO and LCO at 4:00 in the afternoon, and all of a sudden I got paranoid that there was not enough time to properly prep at the pad and then fly the rocket. So I pulled the rocket. Of course, after I pulled the rocket and was loading up the car to leave for the day, Pius Morizumi extended the launch window for two and a half more hours. I was too tired, hungry, and dehydrated at that point to continue, so I left the playa, went to my motel in Fernley, ate a delivered pizza, and went to bed at 8:00 p.m. On Sunday, I had a breakfast of skim milk and water, having learned many years ago that steak and eggs is not a good breakfast for flying rockets on the playa (that much food makes me too drowsy). I hit the playa at 9:00 a.m. and rolled out my ingenious rocket cradles, which are made of one-by-ones from a diagram in a model railroad book. I have two cradles with wheels that I assemble on the playa; in conjunction, the two make a magnificent prep-and-work area for a large rocket. I had to use the car (a rented Cadillac) to transport the rocket to the far pad. The booster lay on the back seat, and I shoved the sustainer through the two open back windows, so that it poked out each side of the car. This may be the upper limit of what one person can handle at a rocket launch. With help from the pad manager, I placed the rocket on a large rail. Everything fit like butter--motor, tubes, rail, etc. One of the most powerful moments in my life was when I wrapped and inserted ignitors into the sustainer and booster and taped everything snug. After the rocket was lifted onto the rail, it became obvious that I needed the large ladder, not the stepladder, to reach the key ports. I climbed the ladder, threw the key on the sustainer (ten feet in the air), and then threw the key on the booster (about seven feet in the air). The time was 11:55 a.m. Wind conditions were very light, the sky was clear, and the sun was bright. At 11:58, the button was pushed. The rocket moved slowly at first, but totally straight. At about 1,000 feet, it started to gain tremendous speed. I remember thinking that the first hurdle had been achieved; it was flying excellently, with perhaps just a slight, extremely slow rotation. At about 5,000 feet, event-one staging took place on schedule; first the rear booster and sustainer separated from inertia, which meant that my construction was perfect, and then the silent crowd and I saw a flame and giant white smoke. Three seconds later, the sound of the sustainer ignition reached the playa. It sounded like a Mac Truck: loud, throaty, distant. The sustainer proceeded straight up. (I had programmed a half-second delay between booster shutdown and sustainer ignition; from experience, I know that it actually takes a second or two longer for the sustainer to ignite.) The rocket flew totally straight, totally out of sight. The crowd cheered wildly. When the rocket reached apogee, we could barely see it turn over. One to two seconds later, event two occured; the drouge chute deployed. I found out later that the chute had instantly shredded. I had been overly influenced by an article in HPR that claimed PML chutes work excellently as drouges and are very strong. Bullpucky. I should have gone with my SkyAngel Super Drouge, an indestructible chute made out of airbag material. This will be the last time I let experts influence me to abandon the commonsense empirical knowledge I've accumulated over the years. So the rocket fell—nose cone, nylon shock cord, and all the rest. And it fell. And it fell. And it fell. At 800 feet, I had one chance left: the close-proximity chute. My heart started beating again as the enormous chute deployed magnificently, and the rocket settled gently onto the playa about a half mile away from the launch pad. The crowd cheered and whooped it up, reminding me of the pod races in Star Wars Episode One. I jumped in the car and drove to the rocket, playing Thunderbirds music on the stereo. I danced around the rocket like a deranged idiot, totally satisfied that I had achieved above and beyond the "Big Boys" level. The booster, which also used G-Whiz electronics, had deployed perfectly and landed about a quarter mile away. I picked it up on my way back to the base camp and realized that I didn't need to fly another rocket that day in any form. This can be a frustrating hobby, yet I had reached a state of satori. I packed all my stuff up, bid adieu to friends, and left. Sidenote: Less than two weeks after the launch, September 11 occurred. It was thought for a time that my two-stage NorthStar would be the last highpowered rocket to fly at Blackrock, Nevada. |
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