Milty's Mag Page four
Space ship Dept:
Every once in a while I start writing a paper on the mathematics of rocket flight, but I never finish it because I know darn well that Swisher or Ley or a half dozen other people know a lot more about it than I do and could write a more completee paper. (Why the hell don't they? There isn't a word on the subject in English, except in unebtainable Astronautics.)
Anyway, I got curious about the length of a time a trip to the moon would take, and having lots of time recently, started calcutating. It didn't take me long to find out that I couldn't solve the diffential equation that appeared, so I applied a series of approximations, assuming straight-line flight, which shoudn't make more than 50% error.
I started with the time-honored axiom that the rocket must reach the speed of 7 miles per second, the velocity of scape, in arder to negotiate a successful voyage. I assumed a physicological acceleration of 100 feet per second per second. (Physiological acceleration is the acceleration actually felt. It is the mechanical acceleration plus the pull of gravity.) It took ten minutes to reach a velocity of 8 miles per second, at a height of 1600 miles. This took into account the varying gravity of the earth. Propulsion was then stopped, and at 40,000 miles, velocity has dropped to 6 miles per second, remained fairly constant from then on, and the rocket reached the moon in about 10 hours.
Ten hours is a short time. If you lowered your maximum velocity to six miles per second, you'd hit the moon at two or three miles per second (I didn't calculate that far) and it would take you about 30 hours, which is still quite a reasonable time. You would save fuel accelerating, and you'd have less velocity to get ride of at the end of the trip, meaning another fuel saving.
What has happened to the velocity of escape? The point which nobody has mentioned, to my knowledge, is the fact that the seven miles per second figure refers to a projectile starting at the surface of the earth with that velocity. The rocket doesn't attain its maximum velocity until it has risen to a height where gravity is cut in half. It's velocity of escapes is less than seven miles per second.
Trouble is, if you are going to the other planets, you want to go faster than that if you are going to get there in any reasonable time. So we still need atomic energy.
Page four stencilled three A.M. April 23, 1944, while sitting in the orderly room as corporal of the guard. .... Hope I remain at this camp long enough to finish Will Durant's "Mansions of Philosophy," which I got from the post library, Very interesting so far. .. But there's no doubt that I'll be elsewhere soon. Perhaps within the week. Certainly by the time the mailing comes out.
Auf Wiedersehn