Dan Ashenfelter wrote: >>>>>>> I have a question about the aerodynamics of SpaceShip 1, specifically the "feather" mode. Is the descent controlled in a manner similar to a free-flight's pop-up dethermalizer or some other means? <<<<<<<
The "Feather" descent pretty much does emulate a pop-stab DT (though it is jackknifing the twin booms and taking part of the rear portion of the wing with it). But it does seem that during the Feather descent, there is a little bit of control possible, I noticed on at least one flight it slowly rotated about the yaw axis in a manner that seemed as though it was being controlled (useful for being able to set up the return to glide pointed in the desired direction back to the landing site). At any rate, the feather descent is self-stabilized once in the atmosphere, so the pilot does not have to do anything to maintain it. However it would not be a good idea to start reentry upside down, so it would be forced to flip over, so the pilot ought to get it into the ballpark attitude before starting to get back into some atmosphere (It has a limited amount of pressurized air onboard for use as �cold thrusters� to control it when in the vacuum of space. The flight that spun so much used up a lot of that pressurized air to stop the spin). The current issue of "Fly R/C" Magazine (ME-163 rocket fighter on the cover) has an article on Rutan and SS1. There are a couple of pics of him as a teenager (in the 1950's) with model airplanes, and 1-2 of the F/F models looked like they were at least capable of pop-stab DT's (A lot of models of those types of F/F designs were often DT'ed, just can't say for sure his were. But he at least would have known about DT's). BTW - In the 1970's, NASA had a small test program that used a modified manned sailplane, with the stab modified to pivot 90 degrees, so effectively like a big DT'ed F/F model, except it could UN-DT itself to return to normal flight. It was investigating "Deep stall" modes and recovery. But the project was not for re-entry, it was more for the "Aeronautics" part of NASA rather than the "Space" part. - George Gassaway RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
