Apollo 5

Description

The unmanned Saturn/Apollo 5 was the first test flight of the Lunar Module (LM). Mission objectives were to verify the ascent and descent stages, the propulsion systems, and the restart operations, and to evaluate the spacecraft structure, LM staging, 2nd stage (S-IVB) and instrument unit (Iu) orbital performance.

After launch, the S-IVB 2nd stage ignited to insert the spacecraft into a 163 x 222 km Earth orbit with a period of 88.3 minutes and an inclination of 31.63 degrees. The nose cone was jettisoned and after a coast of 43 min 52 sec the LM was separated from the LM adapter. The LM entered a 167 x 222 km orbit with a period of 88.4 min and an inclination of 31.63 degrees. A planned descent propulsion system (DPS) of 39 seconds was cut short after only 4 seconds. The burn was designed to simulate deceleration for descent to the lunar surface, but was stopped prematurely due to overly conservative programming of the flight software. An alternate flight plan was put into effect, in which the DPS fired for 26 seconds at 10% thrust and then for 7 seconds at maximum thrust. A third DPS firing was performed 32 seconds later, consisting of a 26 second burn at 10% thrust and 2 seconds at maximum thrust, followed by a burn to simulate an abort during the landing phase, in which the ascent propulsion system (APS) was ignited simultaneously with the DPS being shut down. The APS burn lasted 60 seconds, followed by a 6 min 23 sec firing which depleted APS fuel. At the end of the 11 hr, 10 min test period, both LM stages were left in orbit eventually to reenter and disintegrate. Despite the initial premature DPS shutdown, the mission was deemed a success and operation of all LM systems was confirmed.