Albert L. Hopkins
Encyclopedia
Albert L. Hopkins worked at the US MIT Instrumentation Laboratory (now known as the Draper Lab) during the development of the Apollo Guidance, Navigation, and Control System, or the GN&C
. The system was designed in two forms, one for the command module
and one for the lunar module
. The CM version included an optical system with an integrated scanning telescope
and sextant for erecting and correcting the inertial platform. Albert Hopkins (Assistant Director with MIT lab) together with Ramon Alonso, and Hugh Blair-Smith was a member of the group that designed the computer, designated AGC for Apollo Guidance Computer
, identical in the CM and LM.
The AGC was a 15-bit plus parity
machine with a 1 MHz clock
. It was about one cubic foot in volume and weighed about 80 pounds. It used integrated circuit NOR gate
s, two to a package, but integrated RAM
and ROM
devices had not been developed yet. It had 2,000 words of magnetic ferrite core read-write memory and maybe 24 thousand words of read-only memory in the form of magnetic core
ropes. These cores used metal tape magnetic cores. With such limited computing resources, the software had to be extremely tightly written in assembly code. These computers were designed with extremely long mean times to failure. Some 50 were built by Raytheon
, and none ever had a failure over several years of life. The human interface was a keyboard with ten digit keys and a few auxiliary keys for such things as "+" and "–" and "enter", and a display with three numbers of 5 decimal/octal digits, a two-digit program number, and a two-digit verb and a two-digit noun. The astronauts used it for all phases of command.
After leaving Draper Labs, Albert Hopkins, with his wife Lynne Zaccaria, opened a pottery and antiques shop in South Danbury
, New Hampshire
. They now live in Florida
.
Apollo PGNCS
The Apollo Primary Guidance, Navigation and Control System was a self-contained inertial guidance system that allowed Apollo spacecraft to carry out their missions when communications with Earth were interrupted, either as expected, when the spacecraft were behind the moon, or in case of a...
. The system was designed in two forms, one for the command module
Apollo Command/Service Module
The Command/Service Module was one of two spacecraft, along with the Lunar Module, used for the United States Apollo program which landed astronauts on the Moon. It was built for NASA by North American Aviation...
and one for the lunar module
Apollo Lunar Module
The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back...
. The CM version included an optical system with an integrated scanning telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
and sextant for erecting and correcting the inertial platform. Albert Hopkins (Assistant Director with MIT lab) together with Ramon Alonso, and Hugh Blair-Smith was a member of the group that designed the computer, designated AGC for Apollo Guidance Computer
Apollo Guidance Computer
The Apollo Guidance Computer provided onboard computation and control for guidance, navigation, and control of the Command Module and Lunar Module spacecraft of the Apollo program...
, identical in the CM and LM.
The AGC was a 15-bit plus parity
Parity bit
A parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code....
machine with a 1 MHz clock
Clock
A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece...
. It was about one cubic foot in volume and weighed about 80 pounds. It used integrated circuit NOR gate
NOR gate
The NOR gate is a digital logic gate that implements logical NOR - it behaves according to the truth table to the right. A HIGH output results if both the inputs to the gate are LOW . If one or both input is HIGH , a LOW output results. NOR is the result of the negation of the OR operator...
s, two to a package, but integrated RAM
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
and ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
devices had not been developed yet. It had 2,000 words of magnetic ferrite core read-write memory and maybe 24 thousand words of read-only memory in the form of magnetic core
Magnetic core
A magnetic core is a piece of magnetic material with a high permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, inductors and magnetic assemblies. It is made of ferromagnetic metal such...
ropes. These cores used metal tape magnetic cores. With such limited computing resources, the software had to be extremely tightly written in assembly code. These computers were designed with extremely long mean times to failure. Some 50 were built by Raytheon
Raytheon
Raytheon Company is a major American defense contractor and industrial corporation with core manufacturing concentrations in weapons and military and commercial electronics. It was previously involved in corporate and special-mission aircraft until early 2007...
, and none ever had a failure over several years of life. The human interface was a keyboard with ten digit keys and a few auxiliary keys for such things as "+" and "–" and "enter", and a display with three numbers of 5 decimal/octal digits, a two-digit program number, and a two-digit verb and a two-digit noun. The astronauts used it for all phases of command.
After leaving Draper Labs, Albert Hopkins, with his wife Lynne Zaccaria, opened a pottery and antiques shop in South Danbury
Danbury, New Hampshire
In 1800, there were 165 people living in Danbury, according to the first official census.As of the 2000 census, there were 1,071 people, 435 households, and 310 families residing in the town. The population density was 28.6 people per square mile . There were 596 housing units at an average...
, New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
. They now live in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
.