Instrument Unit (1960s)

[Music] the Apollo Saturn 5 consists of two major parts the launch vehicle and the spacecraft between them is a small ring like section called the instrument unit it's the brain and nerve center of a huge launch [Music] vehicle made of thin wall aluminum honeycomb the unit is nearly 22 ft in diameter the same as the third stage of the Saturn 5 but only 3 ft High yet it supports the Apollo spacecraft and contains the electronic and electrical equipment required for navigation guidance and control of the entire vehicle it also carries equipment for temperature control electric power for the launch vehicle instruments measuring flight operations and Communications with the ground the emergency of boort and destruct systems are monitored in the ring as [Music] well the instrument unit sensors are constantly at work determining the vehicle's position and velocity in other words navigating the Saturn 5 through the atmosphere and in Space the guidance system Compares this information with the plan to flight plan and determines what Corrections have to be sent to the Saturn's engines and telemetered to Earth [Music] [Music] the varying conditions of flight make guidance necessary a standard flight is influenced by winds aoft engine performance and a number of other factors the guidance system constantly corrects for these changing conditions relying on the information from navigation it plots a new flight path so the spacecraft will arrive at its destination traveling at a specific speed and at the same time arriving in the shortest possible time with the least possible expenditure of fuel as can be seen in the test stand control a method of physically altering the course of the vehicle is achieved in most cases by gimal or moving the engines this corrects for variations observed by the guidance and navigation ation systems and steers the vehicle in its selected flight path the four outboard engines on both the first and second stages are gimb the instrument unit computes and controls the direction of the engines and of their thrust the third stage has only one main engine also gimb to provide directional control of thrust however to keep the vehicle from Rolling six smaller engines are used to stabilize the craft here too it's the instrument unit that controls and coordinates these engines in lunar flight once the spacecraft is on its way to the moon the command and service module separates from the lunar module turns and ducks with the lunar [Music] module the third stage and instrument unit are are jettison their job completed the brain of the Saturn 5 the translator between man and machine Navigator Helmsman and computer all of these jobs are done by the small ring called the instrument unit