FRI 25 MAY 2001

Thought for the Day
"It is my belief that nearly any invented quotation, played with confidence, stands a good chance to deceive."
-- Mark Twain

More Rocketry
Yesterday was a perfect day for launching -- clear, sunny, almost no wind. (We're still launching from the neighbor's yard, since the hayfield behind our house has yet to be mowed and rolled, but we expect the field to be ready by June, as it is every year.) We launched four models.
First was the Hyper-X, a ready-to-fly (RTF) model I purchased for instant gratification. It will be my last RTF. You just can't become "one with the rocket" with RTFs the way you can with models you build yourself. There's not much satisfaction in it, and in addition this one was rather poorly designed, I thought. The nosecone recovers using helicopter blades, and the booster is supposed to come down via parachute. However, the blades on the nosecone push the parachute so far down into the body tube that it doesn't want to deploy well. I launched it with a B6-2 engine, it went up to maybe 200 feet. The nosecone spiraled down on its bright fucia blades, but the booster parachute failed to deploy and the rest of the rocket dropped to earth on its own. Fortunately, the body is solidly made and suffered no damage. The second flight of the Hyper-X used a C6-5 engine, which sent it up close to 500 feet. The booster 'chute only partially deployed, and again the main body of the rocket fell on its own. The nosecone, on the other hand, flew quite well -- so well, in fact, that it disappeared into a field across the road and could not be found. I suppose I can use the remains of the Hyper-X for parts, or perhaps fit it with another nosecone, but this is not a priority.
Second came the Heatseeker, which suffered from a shock cord blowout on its first flight a few days ago. I put an A8-3 in it for its first post-repair flight. It didn't go up quite as far as before (maybe 120 feet), possibly because of the slight extra weight from the redone shock cord mount, and it was quite low before the 'chute deployed, but landed safely nonetheless. Its next flight was on a B6-4, which took it up about 350 feet; it deployed beautifully and was recovered safely.
The third rocket launched was the Skywinder, which I finally finished on Tuesday night. This is an ingeniously designed rocket that helicopters down in one piece, although despite the claims on the packaging it does not assemble in "about an hour" unless you don't bother to wait for the glue to dry. It took me several days to put it together, mostly because of having to wait for the glued parts to dry fully. The plastic recovery rotors fold up over the body tube like insect wings, and at apogee the ejection charge pushes the nosecone up a slide and releases them. On the first launch I used a B4-2, which took it up about 200 feet. The rotors deployed successfully, but two of them slipped their mounts on descent, so the Skywinder came down slightly sideways but unhurt. For the second launch I used a C6-3, which sent the rocket up in a spectacular flight to about 500 feet. The rotors deployed flawlessly, and the rocket gently spun straight down -- into a tree. One of the rotor blades got stripped and hung on the far upper branches, but the rocket itself was recovered safely from the lower branches, minus its third rotor. I contacted Estes customer service about getting a replacement rotor (or "spin", as they call it). They were very friendly and were happy to supply the replacement.
The final launch was not exactly a rocket, but a flying-saucer-shaped device called the Snitch. It's the only RTF model worth buying in my opinion, because it isn't so much a model rocket as a rocket-powered toy. It flew up to about 125 feet on a C6-0 engine, then turned over and dropped back to earth on its landing legs. Not awe-inspiring, but easy and fun. If you save it for your last launch, you're virtually guaranteed a successful flight at the end of your rocketing session, although it's also a good one to start off with if you have an audience.

Thought for the Day
"Be warned that being an expert is more than understanding how a system is supposed to work. Expertise is gained by investigating why a system doesn't work."
-- Brian Redman

Thought for the Day
"All laws are simulations of reality."
-- John C. Lilly

Flight Log
Late yesterday afternoon I conducted the first launch of the AGM-57X Heatseeker I built over the weekend (the Skywinder is still under construction). It was almost windless, maybe a slight breeze from the south. With an A8-3 motor, the Heatseeker climbed to about 150 feet, but when the parachute deployed it blew out the little external shock cord retainer, so the nosecone came down on the chute while the body tumbled back in free fall. It landed remarkably gently, however, with virtually no damage except for a very slightly loosened fin. The tiny plastic shock cord retainer was of course lost in the grass, though. I effected repairs by covering the small hole in the body tube where the retainer went with a small square of black electrical tape (fairly inconspicuous since it matches the overall color scheme) and reinstalling the chute with a traditional paper shock cord mount. Weather permitting, I'll test it again this afternoon after work. [Follow-up note: weather did not permit.] Things like this are why you use a low-thrust engine on a rocket's first flight -- if something goes wrong, it doesn't have as far to fall.

Thought for the Day
"A chap was sealed in a rocket ship and shot upwards to see how high he could go. He was told to keep track of the altitude, so he kept counting, 20,000, 30,000, 100,000, 500,000. When he got this far, he said to himself, 'Jesus Christ!' And a very soft voice answered back: 'Yesssss?'"
-- Edna Purviance

Blast Off!
Regular patrons of this site may have noticed that updates have been rather sparse over the past week. This is due to several factors, one of which is reading more actual books instead of spending quite so much time online. But the main reason is model rockets.
Some friends of ours have an 11-year-old boy, and the other night he mentioned model rockets. I was really into model rockets when I was in junior high school, but it had been 25 or 30 years since I thought about them. And suddenly I wanted to build and fly rockets again.
I was pleased to find that the company I used to buy rocket supplies from, Estes, was still in business. I bought a Scorpion starter kit on Friday afternoon, assembled the rocket that night, and was ready to launch it on Saturday morning.
Various factors delayed the launch until the afternoon, but the Scorpion -- renamed the "Betty Boop" -- was ready for her maiden voyage by about 2:00 pm. A number of the neighbors came out to watch. For the first flight I used an A8-3 engine, which took Betty up to about 250-300 feet. The parachute deployed successfully, but it melted slightly due to insufficient recovery wadding.
For the second flight I used a B6-4 engine (along with more wadding). The rocket streaked up to over 500 feet, nearly out of sight, before it popped the chute and drifted down for a near-perfect landing.
The third and final flight of the Betty Boop was powered by a C6-5 engine. It shot up and disappeared completely for several seconds. Then, over 1000 feet up, we saw the parachute eject. The shroud lines tangled and the rocket started spinning down quickly -- too quickly to land safely. It fell whirling, dropping closer, closer... and then the lines somehow untangled themselves, the chute unfolded fully, and a gust of wind took it up again. It was still a couple of hundred feet up when it drifted out of sight over a line of trees. Several hours of searching the field behind the trees proved utterly fruitless, although there's still a standing $5 reward for anyone who can find the Betty Boop.
I'm currently working on building the Skywinder. If updates continue to be sporadic this week, you'll know why.

Puritans vs. Partiers
The other day I read Nathaniel Hawthorne's The Maypole of Merry Mount for the first time in years, and as always, literature is far more enjoyable when you're not reading it for a class. The story involves the inhabitants of an early Massachusetts settlement called Merry Mount, whose activities consist of singing, dancing, and generally having far too a good a time for the nearby Puritans to tolerate. As Hawthorne himself puts it, "Jollity and gloom were contending for an empire." Guess which side won? Some things never change....

Thought for the Day
"Don't Panic!"
-- Douglas Adams