Olga’s Reviews > Rockets: Two Classic Papers > Status Update

Goddard describes in great detail such modern rocketry concepts as staging, parachute staging, escape velocity, and efficient fuel-oxidizer combinations for liquid rocketry. All this at the time when he placed his payload bay on a frame behind the motor, so essentially in its exhaust, in order to stabilize it (he doesn't mention anything about active stabilisation or passive stabilization using fins.)

I take my words back about Goddard's Tsiolkowsky equation being incomplete--he has completely and correctly defined it, using only slightly different terms than we are used to. He aslo coins the term "effective velocity".

Amazing! Goddard observed that a rocket performs better in a vacuum, but failed to conclude that it has to do with the increase in pressure difference. In fact, he though chamber pressure was irrelevant and performance increase was due to a more efficient ignition in a vacuum. He does graze the subject of designing a combustion chamber for operational pressure (air density) but doesn't complete the thought.

Here Goddard makes a very important (ground-breaking for rocketry at the time) discovery: that not only is rocket propulsion possible in a vacuum, but that it gives a better performance than in an air environment.
I also really appreciate the simplicity and high level of detail with which Goddard describes his experiments, so that anyone would be able to produce his results. I admire that.

It's interesting how thrust measurements were taken in the 1910s: pendulums and chalk, sometimes combined with photography. Also curious how back then people were convinced that a rocket would propel itself not by expelling matter, but by "pushing off the air" with the expelled matter, that Goddard spent a great deal of effort to test (or disprove?) that idea.

As an example, in the overview, Goddard describes the contemporary atmospheric model: "troposphere, stratosphere, hydrogen sphere, and geocronium sphere"--people had no idea what lay beyond the stratosphere! Also, early rocket theory seems to have a lot of (empirical? seemingly arbitrary) power relations: proportions to the 5th power, 27th power, etc. I'm really curious about Goddard's testing and recording methods.

An amazing, mind-blowing glimpse into the origins of modern rocketry. Published in 1919, this text was so ahead of its time, so advanced, and at the same time, so primitive, it's amazing to see what progress rocket engineering has made since then.