I recently ran into Mr Williams at one of my companies seminars. I received this email ...
-----Original Message----- From: John Michael Williams [mailto:[EMAIL PROTECTED] Sent: Monday, August 23, 2004 11:26 PM To: Eversole, Rick Subject: Model Rocket Plan Hi Rick. I enjoyed our long conversation after the Cliff presentation last week. I've been thinking about the multiple-rocket throttle idea, for control during flight. I forget the term you used, but I believe you wanted four nozzles (motors), each with finely-adjustable thrust. I don't think it is the best way: The main problem is in testing the rocket: The motor throttling can't be tested unless the thrust is about the same as in-flight, and this means a test with the rocket cabled to a test pad, which would be very stressful: Even if the test seemed OK, and the deflection could be calibrated finely enough, the test itself would seem likely to leave the system in a state of unknown reliability, making the subsequent flight likely to fail. On the other hand, using just one motor (nozzle) with movable deflection plates in the exhaust stream would seem much better: The displacements could be calibrated with the motor off, and the relatively low temperatures, I think, would mean that the deflection plates would not have to be of special refractory material. Of course, corrosive ablation might be an issue. I think just two solenoids would be enough, with feedback-determined deflection under flight-control system control. Using feedback from an attitude reference system, based on a couple of gyroscopes or a solar or stellar image, might mean little or no need for calibration at all. _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
