[AR] Re: Happy Liquid Rocket Day!
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Sun, 17 Mar 2019 14:14:23 -0400 (EDT)
On Sun, 17 Mar 2019, JOHN HALPENNY wrote:
How did Goddard steer his rocket? Liquid fueled rockets were not very
useful until they developed a steering mechanism with vanes or gimbals...
His earliest rockets embodied the Pendulum Fallacy -- he thought putting
the engine at the top would make them fly stably straight up, and of
course it did nothing of the sort and the actual trajectories were more or
less random. (The first flight reached an altitude of about 40ft but
covered about 180ft horizontally, i.e. an average of more than 45deg from
vertical, despite a vertical launch.)
He spent much of the next decade working -- somewhat intermittently due to
the vagaries of funding -- to make gyro-controlled jet vanes (aided by
fins) work, and finally got a successful gyro-controlled flight in 1935.
(Although it only had two-axis control and started to spin near the end.)
Later he successfully demonstrated a slightly eccentric form of engine
gimbaling -- he gimbaled the entire tail section, including the fins.
Henry
Other related posts: