Apollo 5 - Flight

Flight

The launch vehicle for Apollo 5 was the Saturn IB, a smaller rocket than the Saturn V but capable of launching an Apollo spacecraft into Earth orbit. The Saturn IB SA-204 used on Apollo 5 was the one originally intended for Apollo 1. It had been undamaged in the fire at Launch Complex 34 and was reassembled at Launch Complex 37B for the Apollo 5 launch.

The windows of LM-1 were replaced before the flight with solid aluminum plates. To hasten delivery, it was decided to do without the Lunar Module's legs. Without a crew or CSM, there was no need for a launch escape system. As a consequence the assembled rocket was 55 meters (180 ft) tall, compared to the usual CSM stack height of 68 meters (223 ft).

On January 22, 1968, Apollo 5 lifted off just before sunset. The Saturn IB worked perfectly, inserting the second stage and LM into a 163 x 222 km orbit. The nose cone was jettisoned and after a coast of 43 minutes 52 seconds, the LM separated from its adapter, with a 167 x 222 km orbit. After two orbits, the first planned 39 second descent engine burn was started, but aborted by the onboard guidance computer after only 4 seconds. Shortly before launch there was a suspected fuel leak and a decision was made to delay arming the engine until the time of ignition. This change had increased the time required for the propellant tanks to pressurize and thrust to build to the required level.

The ground controllers moved to an alternate plan to fire the descent engine manually two more times. They then performed the "fire in the hole" test and another ascent engine burn.

After 11 hours and 10 minutes the test was over, and control of the two stages was terminated. The stages were left in a low enough orbit that atmospheric drag would soon cause their orbits to decay and re-enter the atmosphere. The ascent stage (1968-007A) re-entered on January 24 and burned up; the descent stage (1968-007B) re-entered on February 12, falling into the Pacific several hundred kilometers southwest of Guam.

Despite the descent engine programming error, NASA deemed the mission a success in demonstrating the LM systems, and a second unmanned flight test using LM-2 was canceled. LM-3 was cleared for the first manned LM flight, which occurred on Apollo 9.