Launch Vehicle Digital Computer

The Launch Vehicle Digital Computer (LVDC) was a computer that provided the autopilot for the Saturn V rocket from launch, through Canary Islands orbit insertion, and the trans-lunar injection burn that would send the Apollo spacecraft to the Moon.

For comparison, as of 2022, researchers at the University of California created a chip capable of running at 1.78 trillion instructions per second,[1] 146 million times faster.

This meant that, for each of the seven stages, one module in any one of the three pipelines could fail, and the LVDC would still produce the correct results.

The LVDC communicated digitally with a Launch Vehicle Data adapter (LVDA).

[citation needed] The LVDC could also respond to a number of interrupts triggered by external events.

[6] The chassis was made of magnesium-lithium alloy LA 141, chosen for its high stiffness, low weight, and good vibration damping characteristics.

[7]: 511  The chassis was divided into a 3 x 5 matrix of cells separated by walls through which coolant was circulated to remove the 138 watts[8] of power dissipated by the computer.

The decision to cool the LVDC by circulating coolant through the walls of the computer was unique at the time and allowed the LVDC and LVDA (part-cooled using this technique) to be placed in one cold plate location due to the three dimensional packaging.

The alloy LA 141 had been used by IBM on the Gemini keyboard, read out units, and computer in small quantities and the larger frame of the LVDC was produced from the largest billets of LA 141 cast at the time and subsequently CNC machined into the frame.