pdafriendly

Ch1-4
Computers in Spaceflight: The NASA ...
burroghs atlas guidance - G...
Creating the computer: government, industry, ...
burroghs atlas guidance - G...
Some Burroughs Transistor Computers - Folklor...
The Atlas Guidance Computer The Burroughs G...
Atlas Guidance Computer - G...
[PDF] Biography of Spacecraft Computer Referen...
Atlas ICBM - Thor Able Ground Guidance Compute...
Gemini Inertial Guidance Sy...
1962 February 22 Proposal for redundant subs...

"1. Overview [8. 1 MB]: Introduces the project. 2. CTL Module [9. 9 MB]: Design and construction of the control module. 3. PROC Module [6. 7 MB]: Design and construction of the processing (CPU) module. 4. MEM Module [6. 8 MB]: Design and construction of the memory module. 5. IO Module [7. 0 MB]: Design and construction of the diskplay/keyboard (DSKY) module. 6. Assembler [0. 5 MB]: A cross-assembler for AGC software development. 7. C++ Simulator [5. 2 MB]: A low-level simulator that runs assembled AGC code. 8. Flight Software [2. 8 MB]: My translation of portions of the COLOSSUS 249 flight software. 9. Test & Checkout [0. 9 MB]: A suite of test programs in AGC assembly language."

"Steering a rocket using proportional navigation depends on three factors. The sideways or lateral acceleration, called latax, given to the rocket must be the product of: (1) the navigation constant times (2) the closing velocity times (3) the target sightline rotation rate. Sounds simple enough. The difficulty comes from how you measure the last one, how you measure the rocket's true orientation and motion rates in space and how you implement the control motions. The multiplier number is always 1 or higher and the closing speed can't be zero if you want to have intercept, so let's look at the last factor. This is the one you want to have be zero, which means that you're on a collision course and you now need no further correction. Approaching impact, the target always appears to be at the SAME angle. Early ship captains knew that this was a sure sign a collision at sea was about happen, and which would ruin their whole day! An interesting curiosity regarding the perfect initial lead angle is that if your rocket has the same vertical speed as the target's constant horizontal speed during its entire flight and the target flies straight, you need only to launch at exactly as many degrees ahead of the target as the target is seen in degrees above the horizon at the instant of launch. If the navigation constant is 2, the sightline angle is always constant and the rocket will move in a circle. (The angle you use is dependent on closing speed.) The navigation constant ideally is 3, needing the least correction over the entire flight. In reality it varies from 2 to 5, depending on the motions of the target and the rocket. The navigation constant depends roughly on the area of the fins and the fin swing angle. This can be measured in a wind tunnel. The closing velocity is how fast the rocket and target come together. But if we're only hitting a towed kite or bunch of balloons, the closing velocity is the vertical velocity. You can find this speed using a BASIC rocket flight dynamics program, providing you know your individual rocket's true parameters. Or you can track it using a camera-theodolite. How do we account for the sightline swing? We don't. An operator watches a TV monitor and controls sightline angle. A concentric circle representing the chosen angle is marked on the screen. The operator is to keep the target on the circle (not centered) with it's flight direction passing thru the center of the screen. Automatic roll control is a must, by using the sun's position or a good model-hel"

Crews began the catch-up by entering the ground-calculated rendezvous angle desired into address 83. The rendezvous angle indicated how much farther along in a 360-degree orbit the rendezvous was to take place. For example, if the crew desired rendezvous one-third orbit ahead, 12000 was entered into address 83 using the MDIU. The interval at which the pilot wanted to see updates was then entered in address 93. For example, if 04000 was entered, the computer would display on the IVI any required velocity changes at 120 degrees from the rendezvous point (the start), 80 degrees to go, and 40 degrees to go. If the IVI indicated that the computer had calculated that such a rendezvous was possible within the designated fuel limits, the astronauts pressed the START button and the IVI displayed the first set of velocity differentials. The pilot then fired the thrusters until the displays were all at zero