Altitude and velocity limits imposed by the spacecraft computer program on the AS-503 mission


As you know, we are currently figuring on using the AS-278 spacecraft computer programs for AS-503. Ed Copps called me the other day to state that the orbital integration routines in the AS-278 program are scaled such that they will only work for altitude less than about 5,400 nautical miles above the surface of the earth and velocities no greater than about 32,700 feet per second. (I am told the maximum values to be encountered in a nominal mission are about 3,900 nautical miles and 29,500 feet per second). He was looking for reassurance that this scaling would not present a constraint on the AS-503 mission, and I told him that I didn’t think it would but I would check here at MSC. In the meantime, MIT is proceeding, assuming that these limits are not unacceptably restrictive for the AS-503 mission. If anyone knows a reason why this is not satisfactory, please let me know immediately.

Terms & Abbreviations


see AS-207/208


see AS-503


AS-207/208 (also known as AS-278) was to have been the first test of the LM in Earth orbit. It was also to have be a dual mission with the command and lunar modules launched on separate Saturn 1Bs. The mission was cancelled after the Apollo 1 fire and the Saturn 1Bs were used to launch Skylab 3 (AS-207) on July 28, 1973 and Skylab 4 (AS-208) on November 16, 1978. The LM was first tested by Apollo 5 in January 1968.


see AS-207/208


Before the Apollo 1 fire, the mission referred to as AS-503 was an unmanned Earth orbit test flight of the LM and CM scheduled for October 1967. The launch vehicle, SA-503 was used for Apollo 8, December 23 1968.

Copps, Ed

Member of the MIT Instrumentation Lab

E. Copps

see Copps, Ed


Massachussets Institute of Technology. In these memos, MIT is shorthand for the MIT Instrumentation Laboratory, created and led by avionics pioneer Charles Stark Draper. It is now known as the Charles Stark Draper Laboratory and became independent of MIT in 1973.


Manned Spacecraft Center. Now known as Johnson Space Center.