That Professor Goddard, with his ‘chair’ in Clark College and the countenancing of the Smithsonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react – to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.
- New York Times, January 30, 1929
Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th Century and it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error.
- New York Times, July 17, 1969
Which isn’t to say that the Times was entirely wrong. A propeller airplane pushes the atmosphere around itself backwards, and thus propels itself forward. A jet aircraft does the same. So does your car, which pushes the road back while the road pushes itself forward. (The earth is very massive, and is not displaces much by your car.)
Rockets are no exception. If they wish to be pushed forward, they have to have something to push backward. Basic conservation of momentum. The Times was wrong in that rockets do have something better than the vacuum to push against: their rocket fuel. In essence a rocket engine shoves the fuel back out of the rocket, and that push in turn send the rocket forward.
I say all this because several of the great pioneers in rocketry like Goddard and von Braun were not always professional well-funded research scientists. They started as curious amateurs. The tradition continues apace today. Last Saturday a man named Steve Eves lauched a 1/10 scale Saturn V rocket. The rocket was of his own construction and cost him about $25,000 – half of that being fuel costs.
It’s a thing of beauty: